Bio

Clinical Focus


  • Diagnostic Radiology
  • Cardiovacular Imaging
  • Radiology

Academic Appointments


Administrative Appointments


  • Medical Director, 3DQ Lab, Department of Radiology (2012 - Present)
  • Chief, Cardiovascular Imaging, Department of Radiology (2011 - Present)
  • Director, Computed Tomography, Stanford Hospital and Clinics (2008 - Present)

Professional Education


  • Internship:AO Krankenhaus Allentsteig (1991) Austria
  • Medical Education:University of Vienna Medical School (1989) Austria
  • Residency:University of Vienna (1997) Austria
  • MD, University of Vienna, Austria, Medicine (1989)

Research & Scholarship

Current Research and Scholarly Interests


Non-invasive Cardiovascular Imaging
Image Post-processing
Contrast Medium Dynamics

Clinical Trials


  • Prognostic Value of Baseline Computed Tomography (CT) Perfusion Parameters of Pancreatic Cancer for Patients Undergoing Stereotactic Body Radiotherapy or Surgical Resection Not Recruiting

    The purpose of this study is first, to determine whether baseline perfusion characteristics of pancreatic cancer, as characterized by CT perfusion studies, can predict tumor response to treatment by stereotactic body radiotherapy (SBRT). The second goal of this study is to determine whether baseline perfusion characteristics in those patients with resectable pancreatic cancer correlate with immunohistologic markers of angiogenesis such as microvessel density and vascular endothelial growth factor (VEGF) expression.

    Stanford is currently not accepting patients for this trial. For more information, please contact Lindee Burton, (650) 725 - 4712.

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  • Perfusion CT as a Predictor of Treatment Response in Patients With Hepatic Malignancies Recruiting

    The purpose of this study is to determine whether baseline CT perfusion characteristics (measurements of blood-flow using CT) of hepatic cancers can predict tumor response to treatment and whether perfusion CT after treatment can be used as a biomarker for response to treatment. Treatment may consist of chemotherapy or stereotactic body radiotherapy (SBRT)or embolization therapy.

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  • Perfusion CT as a Predictor of Treatment Response in Patients With Rectal Cancer Recruiting

    Recent advances in computed tomography (CT) technology have made CT perfusion imaging feasible for the assessment of tumor perfusion in solid tumors of the abdomen. CT perfusion has shown promising results in serving as a noninvasive method of predicting response to therapy in cancer patients. CT perfusion parameters have also been found to correlate with immunohistologic markers of angiogenesis in a number of solid tumors, suggesting a possible role for CT perfusion as a noninvasive biomarker of tumor angiogenesis. The goals of the investigators study are twofold: first, to determine the relationship between baseline CT perfusion characteristics of rectal cancers and their response to treatment, and second, to determine if perfusion CT can be used to subsequently monitor tumor response to treatment. The investigators hope to enroll those patients with locally advanced rectal cancer undergoing standard CT for pre-treatment planning, integrating CT perfusion imaging into the current abdomen/pelvis imaging protocol with close clinical and radiologic follow-up after treatment to determine response to therapy and time to disease progression.

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Teaching

2013-14 Courses


Publications

Journal Articles


  • Prospective optical motion correction for 3D time-of-flight angiography. Magnetic resonance in medicine Kopeinigg, D., Aksoy, M., Forman, C., Straka, M., Seaman, D., Rosenberg, J., Fleischmann, D., Hornegger, J., Bammer, R. 2013; 69 (6): 1623-1633

    Abstract

    Magnetic resonance angiograms are often nondiagnostic due to patient motion. In clinical practice, the available time to repeat motion-corrupted scans is very limited-especially in patients who suffer from acute cerebrovascular conditions. Here, the feasibility of an optical motion correction system to prospectively correct patient motion for 3D time-of-flight magnetic resonance angiography was investigated. Experiments were performed on five subjects with and without parallel imaging (SENSE R = 2) on a 1.5 T unit. Two human readers assessed the data and were in good agreement (kappa: 0.77). The results from this study indicate that the optical motion correction system greatly reduces motion artifacts when motion was present and did not impair the image quality in the absence of motion. Statistical analysis showed no significant difference between the (vendor-provided) SENSE and the nonaccelerated acquisitions. In conclusion, the optical motion correction system tested in this study has the potential to greatly improve 3D time-of-flight angiograms regardless of whether it is used with or without SENSE. Magn Reson Med, 2013. © 2012 Wiley Periodicals, Inc.

    View details for DOI 10.1002/mrm.24423

    View details for PubMedID 22887025

  • Pulmonary Circulation Imaging: Embryology and Normal Anatomy SEMINARS IN ULTRASOUND CT AND MRI Murillo, H., Cutalo, M. J., Jones, R. P., Lane, M. J., Fleischmann, D., Restrepo, C. S. 2012; 33 (6): 473-484

    Abstract

    This review focuses on the embryology and normal imaging anatomy of the pulmonary circulation, with emphasis on the major arterial and venous vasculature. The pulmonary circulation and parenchyma have a complex intertwined embryologic origin. Understanding the embryologic basis of normal pulmonary vasculature aids recognition of anomalies and visceral situs in the chest. Adaptive changes to congenital anomalies of the pulmonary arterial vasculature are used to contrast from normal and review associated temporal adaptive vascular and parenchymal changes.

    View details for DOI 10.1053/j.sult.2012.08.001

    View details for Web of Science ID 000312179300002

    View details for PubMedID 23168059

  • CT patterns of fungal pulmonary infections of the lung: Comparison of standard-dose and simulated low-dose CT EUROPEAN JOURNAL OF RADIOLOGY Christe, A., Lin, M. C., Yen, A. C., Hallett, R. L., Roychoudhury, K., Schmitzberger, F., Fleischmann, D., Leung, A. N., Rubin, G. D., Vock, P., Roos, J. E. 2012; 81 (10): 2860-2866

    Abstract

    To assess the effect of radiation dose reduction on the appearance and visual quantification of specific CT patterns of fungal infection in immuno-compromised patients.Raw data of thoracic CT scans (64 × 0.75 mm, 120 kVp, 300 reference mAs) from 41 consecutive patients with clinical suspicion of pulmonary fungal infection were collected. In 32 patients fungal infection could be proven (median age of 55.5 years, range 35-83). A total of 267 cuboids showing CT patterns of fungal infection and 27 cubes having no disease were reconstructed at the original and 6 simulated tube currents of 100, 40, 30, 20, 10, and 5 reference mAs. Eight specific fungal CT patterns were analyzed by three radiologists: 76 ground glass opacities, 42 ground glass nodules, 51 mixed, part solid, part ground glass nodules, 36 solid nodules, 5 lobulated nodules, 6 spiculated nodules, 14 cavitary nodules, and 37 foci of air-space disease. The standard of reference was a consensus subjective interpretation by experts whom were not readers in the study.The mean sensitivity and standard deviation for detecting pathological cuboids/disease using standard dose CT was 0.91 ± 0.07. Decreasing dose did not affect sensitivity significantly until the lowest dose level of 5 mAs (0.87 ± 0.10, p=0.012). Nodular pattern discrimination was impaired below the dose level of 30 reference mAs: specificity for fungal 'mixed nodules' decreased significantly at 20, 10 and 5 reference mAs (p<0.05). At lower dose levels, classification drifted from 'solid' to 'mixed nodule', although no lesion was missed.Our simulation data suggest that tube current levels can be reduced from 300 to 30 reference mAs without impairing the diagnostic information of specific CT patterns of pulmonary fungal infections.

    View details for DOI 10.1016/j.ejrad.2011.06.059

    View details for Web of Science ID 000308079700067

    View details for PubMedID 21835569

  • Imaging of the Aorta: Embryology and Anatomy SEMINARS IN ULTRASOUND CT AND MRI Murillo, H., Lane, M. J., Punn, R., Fleischmann, D., Restrepo, C. S. 2012; 33 (3): 169-190

    Abstract

    This review focuses on the embryology and anatomy of the aorta with some imaging examples. Dividing the aorta by segments of unique function and embryogenesis facilitates organizing the group of potential anomalies encountered. A basic understanding of the embryologic development of the aorta and its major branches helps in understanding and recognizing typical and atypical anatomic findings. Diagnostic imaging of the aorta and its major branches can be accomplished by invasive and noninvasive methods, based on the clinical scenario and the age of the patient. In this review, computed tomography and magnetic resonance imaging examples are emphasized.

    View details for DOI 10.1053/j.sult.2012.01.013

    View details for Web of Science ID 000305094700002

    View details for PubMedID 22624964

  • State-of-the-Art Computed Tomography Angiography of Acute Aortic Syndrome SEMINARS IN ULTRASOUND CT AND MRI Chin, A. S., Fleischmann, D. 2012; 33 (3): 222-234

    Abstract

    Acute aortic syndrome refers to a spectrum of acute life-threatening aortic abnormalities requiring prompt recognition and treatment. Although underlying pathologies are diverse, presenting signs and symptoms are often indistinguishable clinically, underscoring the role of imaging to make the correct diagnosis. Computed tomography (CT) angiography, a safe and accessible imaging modality, is paramount in accurately confirming or excluding critical aortic lesions, defining location and extent, and describing associated complications. Electrocardiographic gating further improves diagnostic precision of CT, providing motion-free 3- and 4-dimensional imaging of the entire aorta. This article reviews the imaging spectrum and state-of-the-art CT for patients presenting with acute aortic syndrome.

    View details for DOI 10.1053/j.sult.2012.01.003

    View details for Web of Science ID 000305094700005

    View details for PubMedID 22624967

  • Cardiac Paraganglioma: Diagnostic and Surgical Challenges JOURNAL OF CARDIAC SURGERY Huo, J. L., Choi, J. C., DeLuna, A., Lee, D., Fleischmann, D., Berry, G. J., Deuse, T., Haddad, F. 2012; 27 (2): 178-182

    Abstract

    Primary cardiac paragangliomas are rare extra-adrenal tumors. Though they account for less than 1% of all primary cardiac tumors, they are considerable sources of morbidity and mortality. In this case review, we discuss the challenges associated with the diagnosis and management of cardiac paragangliomas.

    View details for DOI 10.1111/j.1540-8191.2011.01378.x

    View details for Web of Science ID 000302172800009

    View details for PubMedID 22273468

  • Antiangiogenic and Radiation Therapy Early Effects on In Vivo Computed Tomography Perfusion Parameters in Human Colon Cancer Xenografts in Mice INVESTIGATIVE RADIOLOGY Ren, Y., Fleischmann, D., Foygel, K., Molvin, L., Lutz, A. M., Koong, A. C., Jeffrey, R. B., Tian, L., Willmann, J. K. 2012; 47 (1): 25-32

    Abstract

    To assess early treatment effects on computed tomography (CT) perfusion parameters after antiangiogenic and radiation therapy in subcutaneously implanted, human colon cancer xenografts in mice and to correlate in vivo CT perfusion parameters with ex vivo assays of tumor vascularity and hypoxia.Dynamic contrast-enhanced CT (perfusion CT, 129 mAs, 80 kV, 12 slices × 2.4 mm; 150 ?L iodinated contrast agent injected at a rate of 1 mL/min intravenously) was performed in 100 subcutaneous human colon cancer xenografts on baseline day 0. Mice in group 1 (n=32) received a single dose of the antiangiogenic agent bevacizumab (10 mg/kg body weight), mice in group 2 (n=32) underwent a single radiation treatment (12 Gy), and mice in group 3 (n=32) remained untreated. On days 1, 3, 5, and 7 after treatment, 8 mice from each group underwent a second CT perfusion scan, respectively, after which tumors were excised for ex vivo analysis. Four mice were killed after baseline scanning on day 0 for ex vivo analysis. Blood flow (BF), blood volume (BV), and flow extraction product were calculated using the left ventricle as an arterial input function. Correlation of in vivo CT perfusion parameters with ex vivo microvessel density and extent of tumor hypoxia were assessed by immunofluorescence. Reproducibility of CT perfusion parameter measurements was calculated in an additional 8 tumor-bearing mice scanned twice within 5 hours with the same CT perfusion imaging protocol.The intraclass correlation coefficients for BF, BV, and flow extraction product from repeated CT perfusion scans were 0.93 (95% confidence interval: 0.78, 0.97), 0.88 (0.66, 0.95), and 0.88 (0.56, 0.95), respectively. Changes in perfusion parameters and tumor volumes over time were different between treatments. After bevacizumab treatment, all 3 perfusion parameters significantly decreased from day 1 (P ? 0.006) and remained significantly decreased until day 7 (P ? 0.008); tumor volume increased significantly only on day 7 (P=0.04). After radiation treatment, all 3 perfusion parameters decreased significantly on day 1 (P < 0.001); BF and flow extraction product increased again on day 3 and 5, although without reaching statistically significant difference; and tumor volumes did not change significantly at all time points (P ? 0.3). In the control group, all 3 perfusion parameters did not change significantly, whereas tumor volume increased significantly at all the time points, compared with baseline (P ? 0.04). Ex vivo immunofluorescent staining showed good correlation between all 3 perfusion parameters and microvessel density (?=0.71, 0.66, and 0.69 for BF, BV, and flow extraction product, respectively; P < 0.001). There was a trend toward negative correlation between extent of hypoxia and all 3 perfusion parameters (?=-0.53, -0.47, and -0.40 for BF, BV, and flow extraction product, respectively; P ? 0.05).CT perfusion allows a reproducible, noninvasive assessment of tumor vascularity in human colon cancer xenografts in mice. After antiangiogenic and radiation therapy, BF, BV, and flow extraction product significantly decrease and change faster than the tumor volume.

    View details for DOI 10.1097/RLI.0b013e31823a82f6

    View details for Web of Science ID 000298400100006

    View details for PubMedID 22178893

  • Coil Embolization of a Left Circumflex Feeder Branch in a Patient With a Mediastinal Paraganglioma JACC-CARDIOVASCULAR INTERVENTIONS Ho, M. Y., Fleischmann, D., Forrester, M. D., Lee, D. P. 2011; 4 (12): 1345-1346

    View details for DOI 10.1016/j.jcin.2011.06.021

    View details for Web of Science ID 000298830500011

    View details for PubMedID 22192376

  • Evaluation of Two Iterative Techniques for Reducing Metal Artifacts in Computed Tomography RADIOLOGY Boas, F. E., Fleischmann, D. 2011; 259 (3): 894-902

    Abstract

    To evaluate two methods for reducing metal artifacts in computed tomography (CT)--the metal deletion technique (MDT) and the selective algebraic reconstruction technique (SART)--and compare these methods with filtered back projection (FBP) and linear interpolation (LI).The institutional review board approved this retrospective HIPAA-compliant study; informed patient consent was waived. Simulated projection data were calculated for a phantom that contained water, soft tissue, bone, and iron. Clinical projection data were obtained retrospectively from 11 consecutively identified CT scans with metal streak artifacts, with a total of 178 sections containing metal. Each scan was reconstructed using FBP, LI, SART, and MDT. The simulated scans were evaluated quantitatively by calculating the average error in Hounsfield units for each pixel compared with the original phantom. Two radiologists who were blinded to the reconstruction algorithms used qualitatively evaluated the clinical scans, ranking the overall severity of artifacts for each algorithm. P values for comparisons of the image quality ranks were calculated from the binomial distribution.The simulations showed that MDT reduces artifacts due to photon starvation, beam hardening, and motion and does not introduce new streaks between metal and bone. MDT had the lowest average error (76% less than FBP, 42% less than LI, 17% less than SART). Blinded comparison of the clinical scans revealed that MDT had the best image quality 100% of the time (95% confidence interval: 72%, 100%). LI had the second best image quality, and SART and FBP had the worst image quality. On images from two CT scans, as compared with images generated by the scanner, MDT revealed information of potential clinical importance.For a wide range of scans, MDT yields reduced metal streak artifacts and better-quality images than does FBP, LI, or SART.http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.11101782/-/DC1.

    View details for DOI 10.1148/radiol.11101782

    View details for Web of Science ID 000290898100030

    View details for PubMedID 21357521

  • Computed tomography-old ideas and new technology EUROPEAN RADIOLOGY Fleischmann, D., Boas, F. E. 2011; 21 (3): 510-517

    Abstract

    Several recently introduced 'new' techniques in computed tomography--iterative reconstruction, gated cardiac CT, multiple-source, and dual-energy CT--actually date back to the early days of CT. We review the historic origins and evolution of these techniques, which may provide some insight into the latest innovations in commercial CT systems.

    View details for DOI 10.1007/s00330-011-2056-z

    View details for Web of Science ID 000286943600013

    View details for PubMedID 21249371

  • Incomplete Endograft Apposition to the Aortic Arch: Bird-Beak Configuration Increases Risk of Endoleak Formation after Thoracic Endovascular Aortic Repair RADIOLOGY Ueda, T., Fleischmann, D., Dake, M. D., Rubin, G. D., Sze, D. Y. 2010; 255 (2): 645-652

    Abstract

    To determine the clinical importance of the bird-beak configuration after thoracic endovascular aortic repair (TEVAR).The institutional review board approved this retrospective study and waived the requirement to obtain informed consent from patients. Sixty-four patients (40 men, 24 women; mean age, 64 years) who underwent TEVAR were evaluated. The treated diseases included dissection (n = 29), degenerative aneurysm (n = 13), acute traumatic transection (n = 8), pseudoaneurysm (n = 4), penetrating aortic ulcer (n = 6), intramural hematoma (n = 2), and mycotic aneurysm (n = 2). Bird-beak configuration, defined as the incomplete apposition of the proximal endograft with a wedge-shaped gap between the device and the aortic wall, was assessed with postprocedural CT angiography. The presence and length of the bird-beak configuration were compared with the formation of endoleaks and adverse clinical events.Endoleaks were detected in 26 (40%) of the 64 patients, including 14 with type Ia endoleak formation, one with type Ib endoleak formation, six with type II endoleak formation (from the left subclavian artery), two with type IIo endoleak formation (from other arteries), and three with type III endoleak formation. Bird-beak configuration was observed in 28 (44%) of 64 patients and correlated significantly with the risk of developing a type Ia or IIa endoleak (P < .01). Mean bird-beak length was significantly longer (P < .01) in patients with a type Ia or II endoleak (mean length, 14.3 and 13.9 mm, respectively) than in patients without endoleaks (mean length, 8.4 mm). Adverse events included early aortic-related death in three patients, additional treatment for endoleak in eight patients, and stent-graft collapse or infolding in six patients.Detection of bird-beak configuration is helpful in the prediction of adverse clinical events after TEVAR.

    View details for DOI 10.1148/radiol.10091468

    View details for Web of Science ID 000276976200040

    View details for PubMedID 20413775

  • CT Angiography: Injection and Acquisition Technique RADIOLOGIC CLINICS OF NORTH AMERICA Fleischmann, D. 2010; 48 (2): 237-?

    Abstract

    CT scanner technology is continuously evolving, with scan times becoming shorter with each scanner generation. Achieving adequate arterial opacification synchronized with CT data acquisition is becoming increasingly difficult. A fundamental understanding of early arterial contrast medium dynamics is thus of utmost importance for the design of CT scanning and injection protocols for current and future cardiovascular CT applications. Arterial enhancement is primarily controlled by the iodine flux (injection flow rate) and the injection duration versus a patient's cardiac output and local downstream physiology. The technical capabilities of modern CT equipment require precise scan timing. Together with automated tube current modulation and weight-based injection protocols, both radiation exposure and contrast medium enhancement can be individualized.

    View details for DOI 10.1016/j.rcl.2010.02.002

    View details for Web of Science ID 000279865000003

    View details for PubMedID 20609872

  • Embolization of a Symptomatic Systemic to Pulmonary (Right-to-left) Venous Shunt Caused by Fibrosing Mediastinitis and Superior Vena Caval Occlusion JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Sze, D. Y., Fleischmann, D., Ma, A. O., Price, E. A., McConnell, M. V. 2010; 21 (1): 140-143

    Abstract

    Paradoxical embolization can occur when a right-to-left shunt allows a venous thromboembolus to escape filtration by the lungs. Venous collateral pathways draining into the left heart incited by superior vena cava obstruction are a rare acquired right-to-left shunt. Herein, the authors report on a case of transient ischemic attack in a patient with vena caval occlusion secondary to histoplasmosis-related fibrosing mediastinitis, with subclavian vein thrombosis and a right-to-left extracardiac shunt diagnosed with echocardiography. Despite the complexity of the collateral network, this shunt was successfully eradicated with coil embolization.

    View details for DOI 10.1016/j.jvir.2009.09.022

    View details for Web of Science ID 000277367500017

    View details for PubMedID 20123198

  • Infolding and collapse of thoracic endoprostheses: Manifestations and treatment options JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY Sze, D. Y., Mitchell, R. S., Miller, D. C., Fleischmann, D., Frisoli, J. K., Kee, S. T., Verma, A., Sheehan, M. P., Dake, M. D. 2009; 138 (2): 324-333

    Abstract

    We sought to review the clinical sequelae and imaging manifestations of thoracic aortic endograft collapses and infoldings and to evaluate minimally invasive methods of repairing such collapses.Two hundred twenty-one Gore endografts (Excluder, TAG; W. L. Gore & Associates, Inc, Flagstaff, Ariz) were deployed in 145 patients for treatment of pathologies including aneurysms and pseudoaneurysms, dissections, penetrating ulcers, transections, fistulae, mycotic aneurysms, and neoplastic invasions in 6 different prospective trials at a single institution from 1997 to 2007. Device collapses and infoldings were analyzed retrospectively, including review of anatomic parameters, pathologies treated, device sizing and selection, clinical sequelae, methods of repair, and outcome.Six device collapses and infoldings were identified. Oversized devices placed into small-diameter aortas and imperfect proximal apposition to the lesser curvature were seen in all proximal collapses, affecting patients with transections and pseudoaneurysms. Infoldings in patients undergoing dissection represented incomplete initial expansion rather than delayed collapse. Delayed collapse occurred as many as 6 years after initial successful deployment, apparently as a result of changes in the aortic configuration from aneurysmal shrinkage. Clinical manifestations ranged from life-threatening ischemia to complete lack of symptoms. Collapses requiring therapy were remedied percutaneously by bare stenting or in one case by branch vessel embolization.Use of oversized devices in small aortas carries a risk of device failure by collapse, which can occur immediately or after years of delay. When clinically indicated, percutaneous repair can be effectively performed.

    View details for DOI 10.1016/j.jtcvs.2008.12.007

    View details for Web of Science ID 000268157800011

    View details for PubMedID 19619775

  • Lower Extremity CT Angiography (CTA): Initial Evaluation of a Knowledge-Based Centerline Estimation Algorithm for Femoro-Popliteal Artery (FPA) Occlusions ACADEMIC RADIOLOGY Roos, J. E., Rakshe, T., Tran, D. N., Rosenberg, J., Straka, M., El-Helw, T., Sofilos, M. C., Napel, S., Fleischmann, D. 2009; 16 (6): 646-653

    Abstract

    Existing density- and gradient-based automated centerline-extraction algorithms fail in severely diseased or occluded arterial segments for the generation of curved planar reformations (CPRs). We aimed to quantitatively and qualitatively assess the precision of a knowledge-based centerline-extraction algorithm in patients with occluded femoro-popliteal artery (FPA).Computed tomography angiograms of 38 FPA occlusions (mean length 120 mm) were retrospectively identified. Reference centerlines were determined as the mean of eight manual expert readings. Each occlusion was also interpolated using a new knowledge-based algorithm (partial vector space projection [PVSP]), which uses shape information extracted from a separate database of 30 nondiseased FPAs. Precision of PVSP was quantified as the maximum departure error (MDE) from the standard of reference and the proportion of the interpolated centerlines remaining within an assumed vessel radius of 3 mm. Multiple regression method was used to determine the factors predicting the precision of the algorithm. CPR quality was independently assigned by two readers.The mean MDE (in mm) for occlusion lengths of <50 mm, 50-100 mm, 100-200 mm, and >200 mm was 0.95, 1.19, 1.40, and 2.25, for manual readings and 1.68, 2.90, 9.43, and 19.95 for PVSP, respectively. MDEs of the algorithm were completely contained within 3 mm of the assumed vessel radius in 20 of 38 occlusions. CPR quality was rated diagnostic by both readers in 23 of 38 occlusions.Shape-based centerline extraction of FPA occlusions in lower extremity CTA is feasible, and independent from local density and gradient information. PVSP centerline extraction allows interpolation of occlusions up to 100 mm within the variability of manually derived centerlines.

    View details for DOI 10.1016/j.acra.2009.01.015

    View details for Web of Science ID 000266210300002

    View details for PubMedID 19427978

  • Value of MDCT Angiography in Developing Treatment Strategies for Critical Limb Ischemia AMERICAN JOURNAL OF ROENTGENOLOGY Schernthaner, R., Fleischmann, D., Stadler, A., Schernthaner, M., Lammer, J., Loewe, C. 2009; 192 (5): 1416-1424

    Abstract

    The purpose of this study was to assess the value of MDCT angiography in the development of strategies for the treatment of patients with critical limb ischemia.During a 12-month period, 150 patients were referred to our department for CT angiography of the peripheral arteries. All patients (n = 28) with clinical stage IV peripheral arterial occlusive disease were included in this retrospective study. The treatment reports, discharge summaries, and follow-up examinations were reviewed to ascertain the number of patients correctly treated on the basis of the CT angiographic findings.After CT angiography, endovascular treatment was indicated for eight patients, surgical revascularization for four patients, and a combined endovascular and surgical approach for two patients. That the correct treatment decision had been made in all 14 cases was confirmed on the basis of successful endovascular or surgical revascularization. In eight patients, medical treatment was indicated, and one patient underwent amputation at the level of the thigh. Five patients were referred for complementary digital subtraction angiography, but no additional findings were made. During follow-up, three of the original 28 patients were in grave general condition and died within 7 weeks after CT angiography. Thirteen patients needed no additional treatment during the follow-up period through January 2008. After a median treatment-free interval of 381 days, 12 patients underwent additional revascularization because of clinical progression of disease.MDCT angiographic findings lead to accurate recommendations for the management of critical limb ischemia. Thus CT angiography seems to be an important technique for the management of stage IV peripheral arterial occlusive disease in patients without absolute contraindications to CT angiography.

    View details for DOI 10.2214/AJR.08.1078

    View details for Web of Science ID 000265387300040

    View details for PubMedID 19380571

  • Dual-energy CT Discrimination of Iodine and Calcium: Experimental Results and Implications for Lower Extremity CT Angiography ACADEMIC RADIOLOGY Tran, D. N., Straka, M., Roos, J. E., Napel, S., Fleischmann, D. 2009; 16 (2): 160-171

    Abstract

    The purpose of this work was to measure the accuracy of dual-energy computed tomography for identifying iodine and calcium and to determine the effects of calcium suppression in phantoms and lower-extremity computed tomographic (CT) angiographic data sets.Using a three-material basis decomposition method for 80- and 140-kVp data, the accuracy of correctly identified contrast medium and calcium voxels and the mean attenuation before and after calcium suppression were computed. Experiments were first performed on a phantom of homogenous contrast medium and hydroxyapatite samples with mean attenuation of 57.2, 126, and 274 Hounsfield units (HU) and 50.0, 122, and 265 HU, respectively. Experiments were repeated in corresponding attenuation groups of voxels from manually segmented bones and contrast medium-enhanced arteries in a lower-extremity CT angiographic data set with mean attenuation of 293 and 434 HU, respectively. Calcium suppression in atherosclerotic plaques of a cadaveric specimen was also studied, using micro-computed tomography as a reference, and in a lower-extremity CT angiographic data set with substantial below-knee calcified plaques.Higher concentrations showed increased accuracy of iodine and hydroxyapatite identification of 87.4%, 99.7%, and 99.9% and 88.0%, 95.0%, and 99.9%, respectively. Calcium suppression was also more accurate with higher concentrations of iodine and hydroxyapatite, with mean attenuation after suppression of 47.1, 122, and 263 HU and 7.14, 11.6, and 12.6 HU, respectively. Similar patterns were seen in the corresponding attenuation groups of the contrast medium-enhanced arteries and bone in the clinical data set, which had overall accuracy of 81.3% and 78.9%, respectively, and mean attenuation after calcium suppression of 254 and 73.7 HU, respectively. The suppression of calcified atherosclerotic plaque was accurate compared with the micro-CT reference; however, the suppression in the clinical data set showed probable inappropriate suppression of the small vessels.Dual-energy computed tomography can detect and differentiate between contrast medium and calcified tissues, but its accuracy is dependent on the CT density of tissues and limited when CT attenuation is low.

    View details for DOI 10.1016/j.acra.2008.09.004

    View details for Web of Science ID 000262536500007

    View details for PubMedID 19124101

  • Optimal Vascular and Parenchymal Contrast Enhancement: The Current State of the Art RADIOLOGIC CLINICS OF NORTH AMERICA Fleischmann, D., Kamaya, A. 2009; 47 (1): 13-?

    Abstract

    A fundamental understanding of early arterial and parenchymal contrast medium (CM) dynamics is the basis for the design of CT scanning and injection protocols for state-of-the-art cardiovascular and body CT applications. Although normal parenchymal enhancement is primarily controlled by the total iodine dose injected per body weight, arterial enhancement is controlled by the iodine flux, the injection duration, and cardiac output. The technical capabilities of modern CT equipment allow and require precise scan timing to synchronize data acquisition with the desired phase of vascular enhancement (for CTA) and parenchymal enhancement (for liver and pancreatic CT). Automated tube current modulation and weight-based injection protocols allow individual optimization of radiation exposure and reduce interindividual variability of CM enhancement.

    View details for DOI 10.1016/j.rcl.2008.10.009

    View details for Web of Science ID 000263843900003

    View details for PubMedID 19195531

  • Surgically palliated double-inlet left ventricle with transposition of the great arteries mistaken for aortic aneurysm with dissection INTERNATIONAL JOURNAL OF CARDIOLOGY Gupta, A., Fleischmann, D., Murphy, D. J., Wu, J. C. 2008; 128 (2): E82-E84

    Abstract

    We report a 23-year-old male with history of double-inlet single ventricle with transposition of the great arteries who is s/p pulmonary artery banding, a Damus-Kaye-Stanzel anastomosis, and Fontan procedure during infancy and childhood who now presents with chest pain. A chest CTA at an outside hospital was thought concerning for the presence of a thoracic aortic aneurysm with dissection, prompting immediate transfer to our institution. However, repeat chest CTA at our institution revealed the predicted anastomoses based on his surgical procedures, which was misinterpreted as aortic aneurysm and dissection. An understanding of the physiology of his surgically repaired congenital heart disease is critical in interpreting his subsequent chest CTA and arriving at the appropriate clinical conclusion.

    View details for DOI 10.1016/j.ijcard.2007.04.165

    View details for Web of Science ID 000257950500043

    View details for PubMedID 17689761

  • Unexpected findings during the anesthetic management of a patient with a cardiac paraganglioma JOURNAL OF CARDIOTHORACIC AND VASCULAR ANESTHESIA Soran, P. D., Akram, S., Mihm, F., Fleischmann, D., Reitz, B., van der Starre, P. 2008; 22 (4): 570-572

    View details for DOI 10.1053/j.jvca.2008.01.019

    View details for Web of Science ID 000258388100011

    View details for PubMedID 18662633

  • An improved algorithm for femoropopliteal artery centerline restoration using prior knowledge of shapes and image space data MEDICAL PHYSICS Rakshe, T., Fleischmann, D., Rosenberg, J., Roos, J. E., Straka, M., Napel, S. 2008; 35 (7): 3372-3382

    Abstract

    Accurate arterial centerline extraction is essential for comprehensive visualization in CT Angiography. Time consuming manual tracking is needed when automated methods fail to track centerlines through severely diseased and occluded vessels. A previously described algorithm, Partial Vector Space Projection (PVSP), which uses vessel shape information from a database to bridge occlusions of the femoropopliteal artery, has a limited accuracy in long (>100 mm) occlusions. In this article we introduce a new algorithm, Intermediate Point Detection (IPD), which uses calcifications in the occluded artery to provide additional information about the location of the centerline to facilitate improvement in PVSP performance. It identifies calcified plaque in image space to find the most useful point within the occlusion to improve the estimate from PVSP. In this algorithm candidates for calcified plaque are automatically identified on axial CT slices in a restricted region around the estimate obtained from PVSP. A modified Canny edge detector identifies the edge of the calcified plaque and a convex polygon fit is used to find the edge of the calcification bordering the wall of the vessel. The Hough transform for circles estimates the center of the vessel on the slice, which serves as a candidate intermediate point. Each candidate is characterized by two scores based on radius and relative position within the occluded segment, and a polynomial function is constructed to define a net score representing the potential benefit of using this candidate for improving the centerline. We tested our approach in 44 femoropopliteal artery occlusions of lengths up to 398 mm in 30 patients with peripheral arterial occlusive disease. Centerlines were tracked manually by four-experts, twice each, with their mean serving as the reference standard. All occlusions were first interpolated with PVSP using a database of femoropopliteal arterial shapes obtained from a total of 60 subjects. Occlusions longer than 80 mm (N = 20) were then processed with the IPD algorithm, provided calcifications were found (N = 14). We used the maximum point-wise distance of an interpolated curve from the reference standard as our error metric. The IPD algorithm significantly reduced the average error of the initial PVSP from 2.76 to 1.86 mm (p < 0.01). The error was less than the clinically desirable 3 mm (smallest radius of the femoropopliteal artery) in 13 of 14 occlusions. The IPD algorithm achieved results within the range of the human readers in 11 of 14 cases. We conclude that the additional use of sparse but specific image space information, such as calcified atherosclerotic plaque, can be used to substantially improve the performance of a previously described knowledge-based method to restore the centerlines of femoropopliteal arterial occlusions.

    View details for DOI 10.1118/1.2940194

    View details for Web of Science ID 000257231700039

    View details for PubMedID 18697561

  • Multidetector CT angiography in the assessment of peripheral arterial occlusive disease: accuracy in detecting the severity, number, and length of stenoses EUROPEAN RADIOLOGY Schernthaner, R., Stadler, A., Lomoschitz, F., Weber, M., Fleischmann, D., Lammer, J., Loewe, C. 2008; 18 (4): 665-671

    Abstract

    The purpose was to evaluate the accuracy of multidetector CT angiography (MD-CTA) in the morphologic assessment of peripheral arterial occlusive disease (PAOD) compared to digital subtraction angiography (DSA). Fifty consecutive patients referred for DSA of the peripheral arteries due to PAOD were prospectively included in this study and underwent 16-row MD-CTA prior to DSA. Maximum intensity projections and multipath curved planar reformations were created with a semi-automated toolbox. Twenty-one vascular segments were defined in each leg and compared to DSA findings with regard to gradation, length, and number of lesions. Mean sensitivity and specificity in the detection of significant stenoses (over 70%) were 100% and 99.5% in the iliac arteries, 97.4% and 99.0% in the femoro-popliteal arteries, and 98.3% and 99.8% in the infrapopliteal arteries, respectively. High kappa values for exact stenoses gradation (0.74-1), lesion length (0.74-1), and number of lesions (0.71-1) were reached by MD-CTA, indicating high agreement with DSA. Non-invasive MD-CTA is an accurate tool for the assessment of all treatment-relevant morphologic information of PAOD (gradation, length, and number of stenoses) compared to DSA.

    View details for DOI 10.1007/s00330-007-0822-8

    View details for Web of Science ID 000254235900003

    View details for PubMedID 18094974

  • The aortopathy of bicuspid aortic valve disease has distinctive patterns and usually involves the transverse aortic arch JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY Fazel, S. S., Mallidi, H. R., Lee, R. S., Sheehan, M. P., Liang, D., Fleischman, D., Herfkens, R., Mitchell, S., Miller, D. C. 2008; 135 (4): 901-U54

    Abstract

    Bicuspid aortic valves are associated with a poorly characterized connective tissue disorder that predisposes to aortic catastrophes. Because no criterion exists dictating the appropriate extent of aortic resection in aneurysmal disease of the bicuspid aortic valve, we studied the patterns of aortic dilation in this population.Sixty-four patients with bicuspid aortic valves who underwent computed tomographic or magnetic resonance angiography and echocardiography were retrospectively identified between January 2002 and March 2006. Orthonormal 2-dimensional or 3-dimensional aortic diameters were measured at 10 levels. Agglomerative hierarchic clustering with centered correlation distance measurements and complete linkage analysis was used to detect distinct patterns of aortic dilatation.Mean aortic diameter was 28.1 +/- 0.7 mm at the annulus and 21.7 +/- 0.4 mm at the diaphragmatic hiatus. The aorta was largest in the tubular ascending aorta (45.9 +/- 1.0 mm). Compared with the descending aorta, the transverse aortic arch was also dilated (P < .01). Cluster analysis showed 4 patterns of aortic dilatation: cluster I, aortic root alone (n = 8, 13%); cluster II, tubular ascending aorta alone (n = 9, 14%); cluster III, tubular portion and transverse arch (n = 18, 28%); and, cluster IV, aortic root and tubular portion with tapering across the transverse arch (n = 29, 45%).Distinct patterns of aortic dilatation in patients with bicuspid aortic valves call for an individualized degree of aortic replacement to minimize late aortic complications and reoperation. Patients in clusters III and IV should have transverse arch replacement (plus concomitant root replacement in cluster IV). Patients in cluster I should undergo complete aortic root replacement, whereas in patients in cluster II supracommissural ascending aortic grafting is adequate.

    View details for DOI 10.1016/j.jtcvs.2008.01.022

    View details for Web of Science ID 000254423600028

    View details for PubMedID 18374778

  • Pre- and postoperative imaging of the aortic root for valve-sparing aortic root repair (V-SARR). Seminars in thoracic and cardiovascular surgery Fleischmann, D., Liang, D. H., Mitchell, R. S., Miller, D. C. 2008; 20 (4): 365-373

    Abstract

    Valve-sparing aortic root repair (V-SARR) using the David reimplantation method is an increasingly popular alternative to composite valve graft aortic root replacement in patients with aortic root aneurysms or dissections who wish to avoid anticoagulation. Computed tomography (CT) with retrospective electrocardiograph (ECG)-gating has become routine before and following V-SARR at Stanford. CT allows accurate measurement of aortic dimensions and provides unprecedented three-dimensional (3D) images of the sinuses, the aortic valve cusps, and coronary arteries in patients with the Marfan syndrome (MFS), with a bicuspid aortic valve (BAV), or other aortic diseases. This helps the surgeon to conceptualize the size of the aortic grafts required and how much reduction is necessary proximally (aortic annulus) and distally. These maneuvers are used to reduce the aortic annular diameter (when necessary) and replace the sinuses and ascending aorta (T. David-V, Stanford modification V-SARR). Postoperative ECG-gated CT confirms the reconstructed geometry and reliably detects coronary or other anastomotic problems.

    View details for DOI 10.1053/j.semtcvs.2008.11.009

    View details for PubMedID 19251178

  • Imaging of the thoracic aorta before and after stent-graft repair of aneurysms and dissections. Seminars in thoracic and cardiovascular surgery Ueda, T., Fleischmann, D., Rubin, G. D., Dake, M. D., Sze, D. Y. 2008; 20 (4): 348-357

    Abstract

    Thoracic endovascular aortic repair (TEVAR) has become widely accepted as an important option for treatment of thoracic aortic diseases. Cross-sectional radiologic imaging plays a crucial role for evaluating a patient's candidacy for planning of the intervention and for assessment of postprocedural results and complications of TEVAR. Recent advances in imaging technologies, in part inspired by advances in stent-graft technology, have drastically changed the character and role of pre- and postprocedural imaging. Three-dimensional (3D) datasets acquired quickly by multidetector computed tomography (MDCT), angiography, or magnetic resonance angiography (MRA) allow multiplanar reformations and 3D viewing, as well as quantitative assessment of vessel lumens, walls, and surroundings. Catheter angiography, in contrast, is performed intraoperatively almost exclusively, and is no longer the gold standard for diagnostic or planning purposes. This article reviews state-of-the-art pre- and postprocedural imaging for TEVAR, especially focusing on the role of MDCT angiography.

    View details for DOI 10.1053/j.semtcvs.2008.11.008

    View details for PubMedID 19251176

  • Technical advances in cardiovascular imaging. Seminars in thoracic and cardiovascular surgery Fleischmann, D., Liang, D. H., Herfkens, R. J. 2008; 20 (4): 333-339

    Abstract

    Cardiovascular imaging technology is continuously evolving and provides an increasing array of tests to evaluate cardiovascular morphology and function. A basic understanding of imaging technology is helpful to select the best modality to answer a specific clinical question. This article provides a brief overview of recent technical developments in computed tomography (CT), magnetic resonance (MR), and echocardiography, which have increased our diagnostic understanding and may modulate treatment planning of patients with cardiovascular diseases: electrocardiographically (ECG)-gated CT, 4D-flow magnetic resonance imaging (MRI), and three-dimensional (3D) echocardiography.

    View details for DOI 10.1053/j.semtcvs.2008.11.015

    View details for PubMedID 19251174

  • Acute aortic syndromes: new insights from electrocardiographically gated computed tomography. Seminars in thoracic and cardiovascular surgery Fleischmann, D., Mitchell, R. S., Miller, D. C. 2008; 20 (4): 340-347

    Abstract

    The development of retrospective electrocardiographic (ECG)-gating has proved to be a diagnostic and therapeutic boon for computed tomography (CT) imaging of patients with acute thoracic aortic diseases, such as aortic dissection/intramural hematoma (AD/IMH), penetrating atherosclerotic ulcer (APU), and ruptured/leaking aneurysm. The notorious pulsation motion artifacts in the ascending aorta confounding regular CT scanning can be eliminated, and involvement of the sinuses of Valsalva, the valve cusps, the aortic annulus, and the coronary arteries in aortic dissection can be clearly depicted or excluded. Motion-free images also allow reliable identification of the site of the primary intimal tear, the location, and extent of the intimomedial flap, and branch artery involvement. ECG-gated CTA also allows the detection of more subtle lesions and variants of aortic dissection, which may ultimately expand our understanding of these complex, life-threatening disorders.

    View details for DOI 10.1053/j.semtcvs.2008.11.011

    View details for PubMedID 19251175

  • Effect of MDCT angiographic findings on the management of intermittent claudication AMERICAN JOURNAL OF ROENTGENOLOGY Schernthaner, R., Fleischmann, D., Lomoschitz, F., Stadler, A., Lammer, J., Loewe, C. 2007; 189 (5): 1215-1222

    Abstract

    The purpose of this study was to assess the reliability of treatment decisions based on MDCT angiographic findings of stage IIb peripheral arterial occlusive disease (PAOD).Fifty-eight patients with stage IIb PAOD underwent CT angiography of the abdominal aorta and runoff vessels for further treatment planning. Treatment reports, discharge summaries, and follow-up examinations were reviewed to determine the number of treatments correctly planned on the basis of CT angiographic findings.On the basis of CT angiographic findings, endovascular treatment was indicated for 18 patients, surgical revascularization for nine patients, and a combined endovascular and surgical approach for two patients. Conservative treatment was indicated for 29 patients. On the basis of successful revascularization, the correctness of the treatment decision was confirmed in all but one patient (n = 28). The treatment plan was modified for one patient referred for surgical revascularization. In that patient, stenosis of the common femoral artery had been overlooked on CT angiography. Patients for whom conservative management was indicated on the basis of CT angiographic findings (n = 29) had a mean follow-up period of 501 days without needing revascularization treatment. This result was defined as indirect confirmation of the accuracy of the decision made with CT angiography.The findings on MDCT angiography led to correct treatment recommendations for patients with claudication. Thus, CT angiography should be used in the management of PAOD.

    View details for DOI 10.2214/AJR.07.2054

    View details for Web of Science ID 000250518500033

    View details for PubMedID 17954664

  • Femoropopliteal artery centerline interpolation using contralateral shape MEDICAL PHYSICS Tran, D. N., Fleischmann, D., Rakshe, T., Roos, J. E., Rosenberg, J., Straka, M., Napel, S. 2007; 34 (9): 3428-3435

    Abstract

    Curved planar reformation allows comprehensive visualization of arterial flow channels, providing information about calcified and noncalcified plaques and degrees of stenoses. Existing semiautomated centerline-extraction algorithms for curved planar reformation generation fail in severely diseased and occluded arteries. We explored whether contralateral shape information could be used to reconstruct centerlines through femoropopliteal occlusions. We obtained CT angiography data sets of 29 subjects (16m/13f, 19-86yo) without peripheral arterial occlusive disease and five consecutive subjects (1m/4f, 54-85yo) with unilateral femoropopliteal arterial occlusions. A gradient-based method was used to extract the femoropopliteal centerlines in nondiseased segments. Centerlines of the five occluded segments were manually determined by four experts, two times each. We interpolated missing centerlines in 2475 simulated occlusions of various occlusion lengths in nondiseased subjects. We used different curve registration methods (reflection, similarity, affine, and global polynomial) to align the nonoccluded segments, matched the end points of the occluded segments to the corresponding patent end points, and recorded maximum Euclidean distances to the known centerlines. We also compared our algorithm to an existing knowledge-based PCA interpolation algorithm using the nondiseased subjects. In the five subjects with real femoropopliteal occlusions, we measured the maximum Euclidean distance and the percentage of the interpolation that remained within a typical 3 mm radius vessel. In the nondiseased subjects, we found that the rigid registration methods were not significantly (p<0.750) different among themselves but were more accurate than the nonrigid methods (p<0.001). In simulations using nondiseased subjects, our method produced centerlines that stayed within 3 mm of a semiautomatically tracked centerline in occlusions up to 100 mm in length; however, the PCA method was significantly more accurate for all occlusions lengths. In the actual clinical cases, we found the following [occlusion length (mm):error (mm)]: 16.5:0.775, 42.0:1.54, 79.9:1.82, 145:3.23, and 292:6.13, which were almost always more accurate than the PCA algorithm. We conclude that the use of contralateral shape information, when available, is a promising method for the interpolation of centerlines through arterial occlusions.

    View details for DOI 10.1118/1.2759603

    View details for Web of Science ID 000249547200003

    View details for PubMedID 17926944

  • Multipath curved planar reformation of the peripheral arterial tree in CT angiography RADIOLOGY Roos, J. E., Fleischmann, D., Koechl, A., Rakshe, T., Straka, M., Napoli, A., Kanitsar, A., Sramek, M., Groeller, E. 2007; 244 (1): 281-290

    Abstract

    The study was approved by the institutional review board, and informed consent was obtained. The purpose of the study was to prospectively quantify the angular visibility range, determine the existence of orthogonal viewing pairs, and characterize the conditions that cause artifacts in multipath curved planar reformations (MPCPRs) of the peripheral arterial tree in 10 patients (eight men and two women; mean age, 69 years; range, 54-80 years) with peripheral arterial occlusive disease. Percentage of segments with the maximal possible visibility score of 1 was significantly greater (odds ratio, 1.42; P<.001) for MPCPRs than for maximum intensity projections. One or more orthogonal viewing pairs were identified for all above-knee arterial segments, and artifactual vessel distortion was observed when the vessel axis approached a horizontal course in MPCPRs.

    View details for DOI 10.1148/radiol.2441060976

    View details for Web of Science ID 000247436500032

    View details for PubMedID 17495179

  • Rapid aneurysmal degeneration of a Stanford type B aortic dissection in a patient with Loeys-Dietz syndrome JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY Lee, R. S., Fazel, S., Schwarze, U., Fleischmann, D., Berry, G. J., Liang, D., Miller, D. C., Mitchell, R. S. 2007; 134 (1): 242-U32

    View details for DOI 10.1016/j.jtcvs.2007.03.004

    View details for Web of Science ID 000247595300041

    View details for PubMedID 17599521

  • Knowledge-based interpolation of curves: Application to femoropopliteal arterial centerline restoration MEDICAL IMAGE ANALYSIS Rakshe, T., Fleischmann, D., Rosenberg, J., Roos, J. E., Napel, S. 2007; 11 (2): 157-168

    Abstract

    We present a novel algorithm, Partial Vector Space Projection (PVSP), for estimation of missing data given a database of similar datasets, and demonstrate its use in restoring the centerlines through simulated occlusions of femoropopliteal arteries, derived from CT angiography data. The algorithm performs Principal Component Analysis (PCA) on a database of centerlines to obtain a set of orthonormal basis functions defined in a scaled and oriented frame of reference, and assumes that any curve not in the database can be represented as a linear combination of these basis functions. Using a database of centerlines derived from 30 normal femoropopliteal arteries, we evaluated the algorithm, and compared it to a correlation-based linear Minimum Mean Squared Error (MMSE) method, by deleting portions of a centerline for several occlusion lengths (OL: 10 mm, 25 mm, 50 mm, 75 mm, 100 mm, 125 mm, 150 mm, 175 mm and 200 mm). For each simulated occlusion, we projected the partially known dataset on the set of basis functions derived from the remaining 29 curves to restore the missing segment. We calculated the maximum point-wise distance (Maximum Departure or MD) between the actual and estimated centerline as the error metric. Mean (standard deviation) of MD increased from 0.18 (0.14) to 4.35 (2.23) as OL increased. The results were fairly accurate even for large occlusion lengths and are clinically useful. The results were consistently better than those using the MMSE method. Multivariate regression analysis found that OL and the root-mean-square error in the 2 cm proximal and distal to the occlusion accounted for most of the error.

    View details for DOI 10.1016/j.media.2006.11.005

    View details for Web of Science ID 000245596200005

    View details for PubMedID 17218147

  • Tools of the trade for CTA: MDCT scanners and contrast medium injection protocols. Techniques in vascular and interventional radiology Hallett, R. L., Fleischmann, D. 2006; 9 (4): 134-142

    Abstract

    The introduction of multi-detector row computed tomography (MDCT) scanners in 1998 ushered in new advances in CT angiography (CTA). The subsequent expansion of MDCT scanner capabilities, coupled with advances in understanding of contrast medium (CM) dynamics, has further improved the clinical availability and consistency of CTA. We will review recent advances in CT scanner technology and discuss early CM dynamics. Specifically, we describe an approach tailored to the available scanner technology and to patient size aimed at providing consistently robust CTA studies across all vascular territories. A rational method to design combined CTA scan/injection protocols to facilitate this goal will be described. Our current experience with a simplified protocol for CTA with 64-MDCT will also be explained.

    View details for PubMedID 17709077

  • Giant coronary aneurysms in heart transplantation: an unusual presentation of cardiac allograft vasculopathy JOURNAL OF HEART AND LUNG TRANSPLANTATION Haddad, F., Perez, M., Fleischmann, D., Valantine, H., Hunt, S. A. 2006; 25 (11): 1367-1370

    Abstract

    Cardiac allograft vasculopathy is a leading cause of death during long-term follow-up of heart transplant recipients. We report 2 cases of cardiac allograft vasculopathy associated with giant coronary aneurysms. To our knowledge, these are the first reported cases of spontaneous giant coronary aneurysms in heart transplant recipients.

    View details for DOI 10.1016/j.healun.2006.07.006

    View details for Web of Science ID 000242222100015

    View details for PubMedID 17097503

  • Peripheral CT angiography for interventional treatment planning. European radiology Fleischmann, D., Lammer, J. 2006; 16: M58-64

    Abstract

    Lower extremity CT angiography (CTA) has evolved into a very effective, widely available and robust imaging modality for patients with peripheral arterial occlusive disease (PAOD). In this article we briefly review the acquisition and contrast administration techniques for 4- through 64-channel peripheral CTA. Visualization of atherosclerotic disease with CTA in general requires 'angiography-like' 3D images (such as volume rendered or maximum intensity projection images), but-notably in the presence of vessel wall calcifications and stents-cross-sectional views (such as curved planar reformations, CPR) are also required to accurately assess the flow lumen of the aorta down to the pedal arteries. Adequate visualization and mapping of atherosclerotic lesions in patients with PAOD is not only a prerequisite for generating a dictated report, but more importantly, standardized postprocessed images are the key to communicating the findings to the treating physician, and they also serve as a treatment planning tool. Treatment decisions (surgical versus transluminal revascularization, or conservative treatment), and percutaneous treatment planning (access site, antegrade versus retrograde puncture) can be made in the majority of patients with PAOD based on lower extremity CT angiograms.

    View details for PubMedID 18655268

  • Unusual case of late thoracic stent graft failure after cardioversion ANNALS OF THORACIC SURGERY Caffarelli, A. D., BANOVAC, F., Cheung, S. C., Fleischmann, D., Mitchell, R. S. 2006; 81 (5): 1875-1877

    Abstract

    We report the unusual case of successful endovascular exclusion of a thoracic aortic aneurysm with subsequent thoracic aortic aneurysm reduction, and development of an interval, acute type III endoleak after cardioversion 5 years after stent graft deployment.

    View details for DOI 10.1016/j.athoracsur.2005.04.087

    View details for Web of Science ID 000237001700052

    View details for PubMedID 16631691

  • PTA versus carbofilm-coated stents in infrapopliteal arteries: Pilot study CARDIOVASCULAR AND INTERVENTIONAL RADIOLOGY Rand, T., Basile, A., Cejna, M., Fleischmann, D., Funovics, M., Gschwendtner, M., Haumer, M., Von Katzler, I., Kettenbach, J., Lomoschitz, F., Luft, C., Minar, E., Schneider, B., Schoder, M., Lammer, J. 2006; 29 (1): 29-38

    Abstract

    To determine the primary success and short-term patency of stent application as a primary treatment modality for high-grade lesions of the infrapopliteal arteries compared with treatment with percutaneous transluminal angioplasty (PTA) in critical limb ischemia in a randomized prospective study.Endovascular therapy was performed on 95 lesions in 51 patients (mean age 72.0 years, range 47-80 years) who presented clinically with Fontaine stages III and IV. One patient underwent treatment in both limbs. After angiographic lesion identification, patients were randomized for treatment by PTA (53 lesions in 27 patients) or stent application (42 lesions in 24 patients). Follow-up by clinical investigation and conventional angiography or spiral CT angiography was performed in 37 patients (57 lesions) 6 to 12 months after the procedure, or when clinically indicated. Evaluation was performed by two observers, double-blinded, with thresholds for lesion restenosis of 50% and 70%. Statistical evaluation was performed on a lesion basis by Kaplan-Meier estimated probability rates, and log-rank and Wilcoxon tests. The primary endpoint was the angiographic patency rate of treated lesions.The inter-reader agreement was high (kappa = 0.82). For the stent group the cumulative primary patency at 6 months was 83.7% at the 70% restenosis threshold, and 79.7% at the 50% restenosis threshold. For PTA, the primary patency at 6 months was 61.1% at the 70% restenosis threshold and 45.6% at the 50% restenosis threshold. Both results were statistically significant (p < 0.05).Infrapopliteal stent application is an effective treatment modality for high-grade lesions in chronic critical limb ischemia. Compared with PTA, higher patency rates can be expected after 6 months.

    View details for DOI 10.1007/s00270-005-0276-9

    View details for Web of Science ID 000234728900006

    View details for PubMedID 16252079

  • CT angiography of peripheral arterial disease JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Fleischmann, D., Hallett, R. L., Rubin, G. D. 2006; 17 (1): 3-26

    Abstract

    Lower-extremity computed tomographic (CT) angiography (ie, peripheral CT angiography) is increasingly used to evaluate patients with peripheral arterial disease. It is therefore increasingly important for all vascular specialists to become familiar with the strengths and limitations of this new technique. The aims of this review are to explain the principles of scanning and injection technique for a wide range of CT scanners, to explain and illustrate the properties of current image postprocessing tools for effective visualization and treatment planning, and to provide an overview of current clinical applications of peripheral CT angiography.

    View details for DOI 10.1097/01.RVI.0000191361.02857.DE

    View details for Web of Science ID 000236517800002

    View details for PubMedID 16415129

  • Peripheral CT angiography for interventional treatment planning European Radiology Fleischmann D, Lammer J 2006; 16 Supp.7: M58-M64
  • How to design injection protocols for multiple detector-row CT angiography (MDCTA) EUROPEAN RADIOLOGY Fleischmann, D. 2005; 15: E60-E65

    Abstract

    The basis of the development of optimal injection protocols for multiple detector-row CT-angiography is knowledge of the physiological and pharmacokinetic principles of arterial enhancement. This article reviews the key rules of early arterial contrast medium dynamics: (1) Arterial enhancement is directly proportional to the iodine administration rate (iodine flux), and can be controlled by the injection flow rate and the iodine concentration of the contrast medium; (2) Arterial enhancement continuously increases over time with longer injection durations, due to the cumulative effects of bolus broadening and recirculation; (3) The strength of an individual's enhancement response to intravenously administered CM depends primarily on the patient's cardiac output and correlates inversely with body weight. In CTA, any of the following strategies can be employed alone, or in combination, to achieve adequate arterial enhancement in spite of short acquisition times: Increasing the injection rate, using higher concentration CM or increasing the injection duration (and scanning delay) relative to the scan time. Both injection volumes and flow rates should be adjusted to body weight, at least for patients < or =60 kg and > or =90kg BW. Rationally designed injection protocols based on physiological concepts allow optimal CM utilisation and take full advantage of the technical capabilities offered by modern MDCT scanners.

    View details for DOI 10.1007/s10406-005-0166-x

    View details for Web of Science ID 000235718500007

    View details for PubMedID 18637231

  • Angiographic imaging of the lower extremities with multidetector CT RADIOLOGIC CLINICS OF NORTH AMERICA Hiatt, M. D., Fleischmann, D., Hellinger, J. C., Rubin, G. D. 2005; 43 (6): 1119-?

    Abstract

    Multidetector CT (MDCT) has improved imaging of the arteries in the lower extremities. The main advantages of this novel technology are the exceptionally fast scan times, high spatial resolution, increased anatomic coverage, and capability to generate high-quality multiplanar reformations and three-dimensional (3-D) renderings from raw data that can be reprocessed easily and quickly. The applications of MDCT in imaging the lower extremities are multiple and varied. They include the evaluation of peripheral arterial occlusive and aneurysmal disease, the patency and integrity of bypass grafts, and arterial injury owing to trauma. This article describes the techniques of lower extremity MDCT angiography and its use in a few clinical applications.

    View details for DOI 10.1016/j.rcl.2005.08.008

    View details for Web of Science ID 000233251800011

    View details for PubMedID 16253665

  • Detection of endograft fractures with multidetector row computed tomography JOURNAL OF VASCULAR SURGERY Roos, J. E., Hellinger, J. C., Hallet, R., Fleischmann, D., Zarins, C. K., Rubin, G. D. 2005; 42 (5): 1002-1006

    Abstract

    Delayed endograft metallic strut failures detected in vivo with multidetector row computed tomography (MDCT) are reported in two patients who underwent endovascular abdominal aortic aneurysm repair with AneuRx and Talent endografts. In both instances, nitinol fractures were associated with proximal migration and type I endoleak. In both cases, the metallic strut fractures were detected with transverse sections from 16-channel MDCT angiograms and confirmed by using volume rendering. These cases highlight the previously unreported ability of thin-section, high-resolution MDCT angiography to detect endograft strut fractures.

    View details for DOI 10.1016/j.jvs.2005.07.009

    View details for Web of Science ID 000233090000038

    View details for PubMedID 16275461

  • Quantification of intravenously administered contrast medium transit through the peripheral arteries: Implications for CT angiography RADIOLOGY Fleischmann, D., Rubin, G. D. 2005; 236 (3): 1076-1082

    Abstract

    To prospectively determine the range of aortopopliteal bolus transit times in patients with moderate-to-severe peripheral arterial occlusive disease (PAOD) as a guideline for developing injection strategies for computed tomographic (CT) angiography of peripheral arteries.The study protocol was approved by the local ethics board, and informed consent was obtained. Twenty patients with PAOD referred for CT angiography of the lower extremities were categorized into two groups, Fontaine stage IIb (group 1) and stage III or IV (group 2), and demographic information was collected. In all patients, a 16-mL test bolus was injected intravenously, and single-level dynamic acquisitions were obtained at the level of the abdominal aorta. After injection of a second 16-mL test bolus, dynamic acquisitions were obtained at the level of the knee (popliteal arteries). Aortopopliteal bolus transit times were calculated by subtracting the time to peak enhancement in the popliteal arteries from that in the aorta. Aortopopliteal transit speeds also were derived. Transit times and speeds were compared graphically between clinical stage groups. The time required for the contrast medium to enhance the entire peripheral arterial tree in patients with PAOD was estimated by using linear extrapolation.Sixteen men and four women with a mean age of 69 years (range, 49-86 years) were included. Twelve patients were included in group 1, and eight patients, in group 2. Aortopopliteal bolus transit times ranged from 4 to 24 seconds (median, 8 seconds) in all subjects, which corresponded to bolus transit speeds of 177 and 29 mm/sec, respectively. Wide overlap of transit times and transit speeds was observed between clinical stage groups. The estimated time needed for the bolus to enhance the entire peripheral arterial tree was 6-39 seconds.Aortopopliteal bolus transit times differ widely among patients and may be substantially delayed in all patients with PAOD. Empirical injection protocols should include an injection duration of 35 seconds or more, as well as an increased scanning delay, with table speeds of more than 30 mm/sec.

    View details for DOI 10.1148/radiol.2363041392

    View details for Web of Science ID 000231412600046

    View details for PubMedID 16000649

  • CT angiography of pulmonary artery aneurysms in Hughes-Stovin syndrome AMERICAN JOURNAL OF ROENTGENOLOGY Ketchum, E. S., Zamanian, R. T., Fleischmann, D. 2005; 185 (2): 330-332

    View details for Web of Science ID 000230738500008

    View details for PubMedID 16037501

  • Computed tomography angiography - State-of-the-art imaging using multidetector-row technology JOURNAL OF COMPUTER ASSISTED TOMOGRAPHY Napoli, A., Fleischmann, D., Chan, F. P., Catalano, C., Hellinger, J. C., Passariello, R., Rubin, G. D. 2004; 28: S32-S45

    Abstract

    Multidetector-row computed tomography (MDCT) is an essential diagnostic modality for many clinical algorithms. This is particularly true with regard to the evaluation of cardiovascular disease. As a result of increased image acquisition speed, improved spatial resolution, and greater scan volume, MDCT angiography (computed tomography angiography [CTA]) has become an excellent noninvasive imaging technique, replacing intra-arterial digital subtraction angiography for most vascular territories. The clinical success of CTA depends on precise synchronization of image acquisition with optimal vascular enhancement. As technology continuously evolves, however, this task can be challenging. It remains important to have a fundamental knowledge of the principles behind technical parameters and contrast medium administration. This article reviews these essential principles, followed by an overview of current clinical applications.

    View details for Web of Science ID 000222968800008

    View details for PubMedID 15258492

  • Successful treatment of a Stanford type A dissection by percutaneous placement of a covered stent graft in the ascending aorta JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY Ihnken, K., Sze, D., Dake, M. D., Fleischmann, D., van der Starre, P., Robbins, R. 2004; 127 (6): 1808-1810

    View details for DOI 10.1016/j.jteves.2003.12.019

    View details for Web of Science ID 000221895700036

    View details for PubMedID 15173740

  • Non-Linear Model Fitting to Parameterize Diseased Blood Vessels IEEE Vizualization 2004 La Cruz A, Straka M, Köchl A, Srámek M, Gröller E, Fleischmann D 2004: 393-400
  • Value of negative spiral CT angiography in patients with suspected acute PE: analysis of PE occurrence and outcome EUROPEAN RADIOLOGY Krestan, C. R., Klein, N., Fleischmann, D., Kaneider, A., Novotny, C., Kreuzer, S., Riedl, C., Minar, E., Janata, K., Herold, C. J. 2004; 14 (1): 93-98

    Abstract

    The aim of this study was to analyze pulmonary embolism (PE) occurrence and retrospective clinical outcome in patients with clinically suspected acute PE and a negative spiral CT angiography (SCTA) of the pulmonary arteries. Within a 35-month period, 485 consecutive patients with clinical symptoms of acute PE underwent SCTA of the pulmonary arteries. Patients with a negative SCTA and without anticoagulation treatment were followed-up and formed the study group. Patient outcome and recurrence of PE was evaluated retrospectively during a period of 6 months after the initial SCTA, and included a review of computerized patient records, and interviews with physicians and patients. Patients were asked to fill out a questionnaire concerning all relevant questions about their medical history and clinical course during the follow-up period. Special attention was focused on symptoms indicating recurrent PE, as well as later confirmation and therapy of PE. Of the 485 patients, 325 patients (67%) had a negative scan, 134 (27.6%) had radiological signs of PE, and 26 (5.4%) had an indeterminant result. Of 325 patients with a negative scan, 269 (83%) were available for follow-up. The main reasons for loss to follow-up were change of address, name, or phone number, or non-resident patients who left abroad. Of 269 patients available for follow-up, 49 patients (18.2% of 269) received anticoagulant treatment because of prior or recent deep venous thrombosis (32.6%) or a history of PE (34.7%), cardiovascular disease (18.4%), high clinical probability (8.2%), positive ventilation-perfusion scan (4.2%), and elevated D-dimer test (2%). The remaining 220 patients, who did not receive anticoagulant medication, formed the study group. Of this study group, 1 patient died from myocardial infarction 6 weeks after the initial SCTA, and the postmortem examination also detected multiple peripheral emboli in both lungs ( p=0.45%; 0.01-2.5, 95% confidence interval). The PE did not occur in any other patient. In patients with suspected PE and negative SCTA without anticoagulant therapy, the risk of recurrent PE in this study was less than 1% and similar to that in patients after a negative pulmonary angiogram. Therefore, we conclude that patients can be managed safely without anticoagulation therapy; however, this approach may not be appropriate for critically ill patients and those with persistent high clinical suspicion of acute PE.

    View details for DOI 10.1007/s00330-003-2016-3

    View details for Web of Science ID 000188208500011

    View details for PubMedID 12942280

  • VesselGlyph: Focus & Context Visualization in CT-Angiography IEEE Visualization 2004 Straka M, Cervenanský M, La Cruz A, Köchl A, Srámek M, Gröller E, Fleischmann D 2004: 385-392
  • Use of high-concentration contrast media in multi pie-detector-row CT: principles and rationale EUROPEAN RADIOLOGY Fleischmann, D. 2003; 13: M14-M20

    Abstract

    Contrast-medium-enhanced multiple-detector-row CT (MDCT) is a powerful technique for vascular and hepatic imaging. With increasingly faster acquisition speeds, which have become possible with latest 8- and 16-channel scanner systems, contrast medium delivery is becoming increasingly difficult. This article reviews the pharmacokinetic and physiologic principles of vascular and hepatic enhancement following the intravenous injection of iodinated contrast medium. The effects of user-selectable injection parameters, such as the injection rate, the injection duration, and the contrast medium concentration on arterial and parenchymal enhancement are elucidated. Equipped with this knowledge, rational injection strategies for CT angiographic protocols for scanners with different acquisition speeds are derived. Furthermore, injection and timing protocols, optimized for hepatic MDCT during the early arterial, late arterial, and parenchymal phases, are developed.

    View details for DOI 10.1007/s00330-003-2097-z

    View details for Web of Science ID 000188877800004

    View details for PubMedID 14989606

  • MDCT of renal and mesenteric vessels EUROPEAN RADIOLOGY Fleischmann, D. 2003; 13: M94-M101

    Abstract

    Computed tomography angiography (CTA) with multiple detector-row CT (MDCT) has evolved into an established technique for non-invasive imaging of renal and mesenteric vessels. With adequate selection of acquisition parameters (thin collimation) high spatial-resolution volumetric data sets for subsequent 2D and 3D reformation can be acquired. Contrast medium (CM) injection parameters need to be adjusted to the acquisition speed of the scanners. Whereas fast acquisitions allow a reduction of total CM volume in the setting of CTA, this is not the case when CTA is combined with a second-phase abdominal MDCT acquisition for parenchymal (e.g., hepatic) imaging. Renal CTA is an accurate and reliable test for visualizing vascular anatomy and renal artery stenosis, and therefore a viable alternative to MRA in the assessment of patients with renovascular hypertension and in potential living related renal donors. CTA, combined with abdominal/parenchymal MDCT is a first-line diagnostic test in patients with suspected abdominal vascular emergencies, such as acute mesenteric ischemia, and an excellent tool to assess a wide variety of vascular abnormalities of the abdominal viscera.

    View details for DOI 10.1007/s00330-003-2103-5

    View details for Web of Science ID 000188877800015

    View details for PubMedID 14989617

  • Future prospects in MDCT imaging EUROPEAN RADIOLOGY Fleischmann, D. 2003; 13: M127-M128

    View details for DOI 10.1007/s00330-003-2106-2

    View details for Web of Science ID 000188877800020

    View details for PubMedID 14989622

  • High-concentration contrast media in MDCT angiography: principles and rationale EUROPEAN RADIOLOGY Fleischmann, D. 2003; 13: N39-N43

    View details for Web of Science ID 000188320400005

    View details for PubMedID 15015879

  • Use of high concentration contrast media: principles and rationale - vascular district EUROPEAN JOURNAL OF RADIOLOGY Fleischmann, D. 2003; 45: S88-S93

    Abstract

    Optimal contrast medium delivery remains a crucial issue in CT angiography and it will become even more critical with continuously evolving, faster CT scanner technology. This review article first explains the fundamentals of arterial enhancement using mathematical models of early contrast medium dynamics. The relationship of contrast medium volume, injection flow rates and injection duration are explicitly illustrated. Next, current techniques of contrast medium application are reviewed, with particular attention to methods of accurate timing of the scanning delay (test-bolus and automated bolus triggering), tools for automated saline-flushing of the veins (double-syringe power injectors) and the use of high-concentration contrast medium. From there, rational CT angiographic injection protocols for a wide range of selectable acquisition times for 4-, 8- and 16-channel MDCT are proposed.

    View details for DOI 10.1016/S0720-048X(02)00365-0

    View details for Web of Science ID 000181595800015

    View details for PubMedID 12598032

  • Multiple detector-row CT angiography of the renal and mesenteric vessels EUROPEAN JOURNAL OF RADIOLOGY Fleischmann, D. 2003; 45: S79-S87

    Abstract

    Computed tomography angiography (CTA) of the abdomen with multiple detector-row computed tomography (MD-CT) is an effective technique for minimally invasive imaging of the renal arteries and the visceral vasculature. This article reviews the clinical and technical aspects of MD-CT angiography in terms of image acquisition and reconstruction parameters, contrast medium application, and three-dimensional visualization with special attention to renal and mesenteric vascular imaging. Because of its high sensitivity to detect renal artery stenosis on the one hand, and because a normal renal CTA virtually excludes the presence of a significant renal artery stenosis on the other hand, renal CTA plays a useful role in the management of patients with suspected renovascular hypertension. Mesenteric CTA is a useful tool for visualizing normal vascular anatomy and its variants-particularly in the setting of organ transplantation. Vascular pathology, e.g. atherosclerotic disease (abdominal angina), or aneurysms of the visceral arteries are reliably assessed with CTA. Mesenteric CTA is an invaluable adjunct to abdominal CT in the setting of abdominal emergencies, because of its ability to detect the causes of acute intestinal ischemia (superior mesenteric artery embolism or thrombosis, superior mesenteric vein thrombosis). Accurate timing of the CTA acquisition and the subsequent parenchymal phase acquisition relative to the contrast medium transit time is critical to obtain excellent image quality in double-pass abdominal CT acquisitions.

    View details for DOI 10.1016/S0720-048X(02)00364(02)00364-9

    View details for Web of Science ID 000181595800014

    View details for PubMedID 12598031

  • Advanced Curved Planar Reformation: Flattening of Vascular Structures IEEE Visualization 2003 Kanitsar A, Wegenkittl R, Fleischmann D, Gröller E 2003: 43-50
  • Bone Segmentation in CT Angiography Data Using a Probabilistic Atlas Vision, Modeling, and Visualization VMV 2003 Straka M, La Cruz A, Köchl A, Dimitrov LI, Srámek M, Fleischmann D, Gröller E 2003: 505-512
  • Endovascular stent-graft repair of complicated penetrating atherosclerotic ulcers of the descending thoracic aorta JOURNAL OF VASCULAR SURGERY Schoder, M., Grabenwoger, M., Holzenbein, T., Domanovits, H., Fleischmann, D., Wolf, F., Cejna, M., Lammer, J. 2002; 36 (4): 720-726

    Abstract

    To report our initial experience with endovascular stent-graft repair of complicated penetrating atherosclerotic ulcers as an alternative to surgery in patients with increased risk of perioperative morbidity and mortality.During a 2-year period, eight patients with complicated penetrating atherosclerotic ulcers of the descending thoracic aorta were treated with the Gore Excluder stent-graft. Patients (mean age, 70.6 years) presented with two to five comorbid conditions causing an increased risk for surgical repair. In addition to painful events, three patients presented with severe hemoptysis, one patient with shortness of breath, and one patient with dysphagia. All patients underwent emergency computed tomography, and diagnosis of contained rupture was confirmed in five patients. Computed tomographic findings included one to three penetrating ulcers per patient (n = 4), pseudoaneurysms (n = 5), additional intramural hematomas (n = 4), mediastinal bleeding (n = 2), and hematothoraces (n = 4). Through an iliac or femoral access site, a total of 11 stent-grafts were implanted under general (n = 5), epidural (n = 2), or spinal (n = 1) anesthesia.Deployment of stent-grafts was successful in all patients, and all sites of hemorrhage were sealed. The intramural hematoma resolved completely in three cases, and two pseudoaneurysms decreased in size. Intentional occlusion of the origin of left subclavian artery with the stent-graft in one patient was tolerated without left arm or cerebral symptoms. One patient experienced permanent paraplegia immediately after endovascular repair. There were no deaths during the hospital stay (range, 7-35 days; mean, 14.5 days). One patient was lost to follow-up after hospital discharge. The clinical observation period for the remaining seven patients was 38 to 99 weeks (mean, 60 weeks).Endovascular stent-graft repair in complicated penetrating atherosclerotic ulcers is an alternative therapeutic option to conventional thoracotomy, especially in patients at high risk of increased morbidity and mortality perioperatively and postoperatively.

    View details for DOI 10.1067/mva.2002.126090

    View details for Web of Science ID 000178617900012

    View details for PubMedID 12368732

  • Present and future trends in multiple detector-row CT applications: CT angiography EUROPEAN RADIOLOGY Fleischmann, D. 2002; 12: S11-S15

    View details for Web of Science ID 000177530300003

    View details for PubMedID 12232656

  • Images in cardiovascular medicine. Left main coronary artery compression by the pulmonary trunk in pulmonary hypertension. Circulation Bonderman, D., Fleischmann, D., Prokop, M., Klepetko, W., Lang, I. M. 2002; 105 (2): 265-?

    View details for PubMedID 11790711

  • Christmas Tree Case Study: Computed Tomography as a Tool for Mastering Complex Real World Objects with Applications in Computer Graphics IEEE Visualization 2002 Kanitsar A, Theußl T, Mroz L, Srámek M, Vilanova Bartrolí A, Csébfalvi B, Hladuvka J, Fleischmann D, Knapp M, Wegenkittl R, Felkel P, Guthe S, Purgathofer W, Gröller E 2002: 489-492
  • CPR - Curved Planar Reformation IEEE Visualization 2002 Kanitsar A, Fleischmann D, Wegenkittl R, Felkel P, Gröller E 2002: 37-44
  • [CT angiography (CTA)]. Wiener medizinische Wochenschrift. Supplement Fleischmann, D. 2002: 53-58

    Abstract

    Computed tomography angiography (CTA) is today a well-established diagnostic technique for non-invasive vascular imaging and has replaced diagnostic intra-arterial angiography. Especially since the implementation of multi detector-row computed tomography (MDCT) the acquisition of isotropic data sets is possible, thus widening the spectrum of clinical application of multi detector-row computed tomography. Compared to intra-arterial angiography computed tomography angiography is less invasive and cheaper.

    View details for PubMedID 12621843

  • Internal iliac artery embolization before endovascular repair of abdominal aortic aneurysms: Frequency, efficacy, and clinical results AMERICAN JOURNAL OF ROENTGENOLOGY Schoder, M., Zaunbauer, L., Holzenbein, T., Fleischmann, D., Cejna, M., Kretschmer, G., Thurnher, S., Lammer, J. 2001; 177 (3): 599-605

    Abstract

    The aim of our study was to assess the frequency, efficacy, and incidence of adverse effects of internal iliac artery embolization.Of 343 patients examined for stent-graft repair, 147 were suitable for endovascular treatment. Fifty-five patients underwent preprocedural embolization of the internal iliac artery either unilaterally (46 patients) or bilaterally (nine patients). Successful embolization was assessed angiographically and with helical CT follow-up examinations. Colonic ischemia was ruled out clinically or colonoscopically. Buttock claudication, and sexual dysfunction in men, were evaluated through a questionnaire.Embolization of the internal iliac artery increased by 16% the percentage of patients for whom endovascular repair was suitable. After successful embolization in all patients, routine CT follow-up examinations after a mean time of 16.7 months showed no evidence of endoleaks related to retrograde perfusion via embolized internal iliac arteries. Nevertheless, in all patients who had undergone embolization, a primary endoleak was detected in 43.4% at the first postoperative CT examination. None of our patients had evidence of colonic ischemia. Clinical follow-up data of 46 patients were available. Of these patients, mild to severe new onset buttock claudication was found in 13 (36.1%) of 36 patients with unilateral, and in eight (80%) of 10 patients with bilateral, internal iliac artery embolization (p = 0.03). Five (25%) of 20 men had an erectile dysfunction after the procedure.Embolization of the internal iliac artery is a safe and efficient procedure that increases the applicability for endovascular repair of aortoiliac aneurysms. However, buttock claudication and erectile dysfunction are a drawback in a substantial number of patients.

    View details for Web of Science ID 000170672000015

    View details for PubMedID 11517053

  • Three-dimensional visualization of pulmonary thromboemboli in chronic thromboembolic pulmonary hypertension with multiple detector-row spiral computed tomography CIRCULATION Fleischmann, D., Scholten, C., Klepetko, W., Lang, I. M. 2001; 103 (24): 2993-2993

    View details for Web of Science ID 000169436000024

    View details for PubMedID 11413092

  • Iliac arterial injuries after endovascular repair of abdominal aortic aneurysms: Correlation with iliac curvature and diameter RADIOLOGY Tillich, M., Bell, R. E., Paik, D. S., Fleischmann, D., Sofilos, M. C., Logan, L. J., Rubin, G. D. 2001; 219 (1): 129-136

    Abstract

    To determine the relationship between iliac arterial tortuosity and cross-sectional area and the occurrence of iliac arterial injuries following transfemoral delivery of endovascular prostheses for repair of abdominal aortic aneurysms.Iliac arterial curvature values and orthogonal cross-sectional areas were determined from helical computed tomographic (CT) data acquired in 42 patients prior to transfemoral delivery of aortic stent-grafts. The curvature and luminal cross-sectional area orthogonal to the median centerline were quantified every millimeter along the median centerline of the iliac arteries. An indicator of global iliac tortuosity, the iliac tortuosity index, was defined as the sum of the curvature values for all points with a curvature of 0.3 cm(-1) or greater, and cross-sectional area (CSA) was indexed for all points as the mean cross-sectional diameter (D = 2 radical[CSA/pi]). Following stent-graft deployment, helical CT data were analyzed for the presence of iliac arterial dissections independently by two reviewers.Eighteen dissections were detected in 16 patients. The iliac tortuosity index was significantly larger in iliac arteries with dissections (35.5 +/- 20.8 [mean +/- SD]) when compared with both nondissected contralateral iliac arteries in the same patients (26.1 +/- 21.0, P =.001) and iliac arteries in patients without any iliac arterial injury (20 +/- 9, P =.009). The tortuosity index was higher ipsilateral to the primary component delivery in 10 of 11 iliac dissections that developed along the primary component delivery route.A high degree of iliac arterial tortuosity appears to impart greater risk for the development of iliac arterial injuries in patients undergoing transfemoral delivery of endovascular devices.

    View details for Web of Science ID 000167667400019

    View details for PubMedID 11274547

  • Accuracy of predicting and controlling time-dependent aortic enhancement from a test bolus injection JOURNAL OF COMPUTER ASSISTED TOMOGRAPHY Hittmair, K., Fleischmann, D. 2001; 25 (2): 287-294

    Abstract

    The purpose of this work was to determine the accuracy of predicting arterial enhancement from peripheral versus central venous test bolus injections at CT angiography (CTA).In 40 patients with abdominal aortic aneurysms, aortoiliac enhancement profiles were predicted by mathematical deconvolution of the time-attenuation response to a 16 ml test bolus injection. Injection sites were either a cubital vein (n = 20) or a central venous injection site (n = 20). The accuracy of predicting enhancement was quantified as the "off-predicted deviation" (calculated as mean squared differences between observed minus predicted enhancement values) in all patients.Off-predicted deviation was significantly smaller in the central venous injection group (17 +/- 6 HU) than the peripheral injection group (33 +/- 18 HU) (p < 0.001).Arterial enhancement at CTA can be mathematically predicted and controlled more accurately if a central venous injection site is used. Automated saline flushing of the veins might improve the accuracy of the mathematical model for peripheral injections.

    View details for Web of Science ID 000167521000024

    View details for PubMedID 11242230

  • Long-term MRI observations of childhood-onset relapsing-remitting multiple sclerosis NEUROPEDIATRICS Balassy, C., Bernert, G., Wober-Bingol, C., Csapo, B., Kornek, B., Szeles, J., Fleischmann, D., Prayer, D. 2001; 32 (1): 28-37

    Abstract

    Long-term MRI follow-up of childhood-onset relapsing-remitting multiple sclerosis (RRMS) was carried out in 4 cases. MRI findings were correlated with clinical course and characteristic differences from adult-onset RRMS were elaborated.Two girls and one boy with true childhood-onset, and one girl with juvenile-onset RRMS underwent 5-16 MRI examinations within 6-8 years. The total number of lesions, the numbers of new, active, disappearing and reappearing lesions, infratentorial and U-fibre lesions, "giant" plaques and "black holes" were counted. Callosal atrophy and general brain atrophy were assessed. The findings were related to the physical status according to the Expanded Disability Status Scale (EDSS).Results showed that the primary differences in childhood-onset RRMS compared to adult-onset RRMS lie in the lack of, or slower development of irreversible changes ("black hole" formation, brain atrophy). Despite callosal atrophy and intensive U-fibre region involvement, school performance was unchanged. Regarding the frequency of "giant" lesions, an even more pronounced white matter involvement was found in our children compared to adults. All children exhibited a rather "benign" disease course. A more intensive remyelination, less severe neuronal loss, and higher functional brain plasticity at younger ages may account for these differences.

    View details for Web of Science ID 000167884600005

    View details for PubMedID 11315199

  • Computed Tomography Angiography: A Case Study of Peripheral Vessel Investigation IEEE Visualization 2001 Kanitsar A, Wegenkittl R, Felkel P, Fleischmann D, Sandner D, Gröller E 2001: 477-480
  • Equipment availability and diagnostic strategies for suspected pulmonary embolism in Austria EUROPEAN RADIOLOGY Schibany, N., Fleischmann, D., Thallinger, C., Schibany, A., Hahne, J., Ba-Ssalamah, A., Herold, C. J. 2001; 11 (11): 2287-2294

    Abstract

    The aim of this study was to investigate equipment availability and current diagnostic strategies for suspected pulmonary embolism (PE) in Austrian hospitals. A questionnaire was sent to the medical directors of all Austrian hospitals with emergency and/or surgical, orthopedic, and medical departments. The questionnaire contained questions regarding the available equipment suitable for the imaging diagnosis of PE, the first-line and second-line imaging tests for patients with suspected PE, and additional lower extremity venous imaging and laboratory tests that complement the diagnostic armamentarium. The return rate for questionnaires was 81% (127 of 157 hospitals). There were 97% of hospitals that had the equipment to perform sonography, 59% could perform pulmonary angiography, 54% spiral CT, 19% ventilation/perfusion (V/P) scintigraphy, and 4% perfusion scintigraphy alone. Spiral-CT angiography (SCTA) was the first-line imaging study for suspected PE in 56% of hospitals, followed by echocardiography and V/P scintigraphy. Lower extremity venous imaging (47%) and, interestingly, V/P scintigraphy (43%), served as second-line imaging tests. D-dimer tests were included in the diagnostic strategy in 74% of hospitals. Spiral-CT angiography is the most commonly used primary method for suspected PE in Austrian hospitals. The V/P scintigraphy is available only in a minority of hospitals to investigate patients with suspected PE. When V/P scintigraphy is available, however, it is employed in a large number of patients per annum.

    View details for Web of Science ID 000172277300024

    View details for PubMedID 11702174

  • Quantitative determination of age-related geometric changes in the normal abdominal aorta JOURNAL OF VASCULAR SURGERY Fleischmann, D., Hastie, T. J., Dannegger, F. C., Paik, D. S., Tillich, M., Zarins, C. K., Rubin, G. D. 2001; 33 (1): 97-105

    Abstract

    We conducted a novel quantitative three-dimensional analysis of computed tomography (CT) angiograms to establish the relationship between aortic geometry and age, sex, and body surface area in healthy subjects.Abdominal helical CT angiograms from 77 healthy potential renal donors (33 men/44 women; mean age, 44 years; age range, 19-67 years) were selected. In each dataset, orthonormal cross-sectional area and diameter measurements were obtained at 1-mm intervals along the automatically calculated central axis of the abdominal aorta. The aorta was subdivided into six consecutive anatomic segments (supraceliac, supramesenteric, suprarenal, inter-renal, proximal infrarenal, and distal infrarenal). The interrelated effects of anatomic segment, age, sex, and body surface area on cross-sectional dimensions were analyzed with linear mixed-effects and varying-coefficient statistical models.We found that significant effects of sex and of body surface area on aortic diameters were similar at all anatomic levels. The effect of age, however, was interrelated with anatomic position, and gradually decreasing slopes of significant diameter-versus-age relationships along the aorta, which ranged from 0.14 mm/y (P <.0001) proximally to 0.03 mm/y (P =.013) distally in the abdominal aorta, were shown.The abdominal aorta undergoes considerable geometric changes when a patient is between 19 and 67 years of age, leading to an increase of aortic taper with time. The hemodynamic consequences of this geometric evolution for the development of aortic disease still need to be established.

    View details for Web of Science ID 000166576900022

    View details for PubMedID 11137929

  • High-resolution CT of diffuse interstitial lung disease: key findings in common disorders EUROPEAN RADIOLOGY Schaefer-Prokop, C., Prokop, M., Fleischmann, D., Herold, C. 2001; 11 (3): 373-392

    Abstract

    High-resolution CT (HRCT) is the radiological imaging technique that most closely reflects changes in lung structure. It represents the radiological method of choice for the diagnostic work-up of patients with known or suspected diffuse interstitial lung disease. A single HRCT finding is frequently nonspecific, but the combination of the various HRCT findings together with their anatomic distribution can suggest the most probable diagnosis. The purpose of this article is to summarize the classic HRCT features of the most common diffuse interstitial lung diseases. Lists of differential diagnoses and distinguishing key features are provided to improve diagnostic confidence. The presence of classic HRCT features often obviates the need for biopsy. In patients with atypical findings, HRCT can be used to determine the most appropriate biopsy site.

    View details for Web of Science ID 000167273600002

    View details for PubMedID 11288840

  • Early pulmonary involvement in ankylosing spondylitis: Assessment with thin-section CT CLINICAL RADIOLOGY Turetschek, K., Ebner, W., Fleischmann, D., Wunderbaldinger, P., Erlacher, L., Zontsich, T., Bankier, A. A. 2000; 55 (8): 632-636

    Abstract

    To determine the frequency and the distribution of early pulmonary lesions in patients with ankylosing spondylitis (AS) and a normal chest X-ray on thin-section CT and to correlate the CT findings with the results of pulmonary function tests and clinical data.Twenty-five patients with clinically proven AS and no history of smoking underwent clinical examinations, pulmonary function tests (PFT), chest radiography, and thin-section CT. Four of 25 patients (16%), who had obvious signs on plain films suggestive of pre-existing disorders unrelated to AS were excluded.Fifteen of 21 patients (71%) had abnormalities on thin-section CT. The most frequent abnormalities were thickening of the interlobular septa in seven of 21 patients (33%), mild bronchial wall thickening in (6/21, 29%), pleural thickening and pleuropulmonary irregularities (both 29%) and linear septal thickening (6/21, 29%). In six patients there were no signs of pleuropulmonary involvement. Eight of 15 patients (53%) with abnormal and four of six patients (67%) with normal CT findings revealed mild restrictive lung function impairment.Patients with AS but a normal chest radiograph frequently have abnormalities on thin-section CT. As these abnormalities are usually subtle and their extent does not correlate with functional and clinical data, the overall routine impact of thin-section CT in the diagnosis of AS is limited.

    View details for Web of Science ID 000088802000009

    View details for PubMedID 10964736

  • Partial fat-saturated contrast-enhanced three-dimensional MR angiography compared with non-fat-saturated and conventional fat-saturated MR angiography RADIOLOGY Hilfiker, P. R., Herfkens, R. J., Heiss, S. G., Alley, M. T., Fleischmann, D., Pelc, N. J. 2000; 216 (1): 298-303

    Abstract

    Abdominal three-dimensional magnetic resonance angiography was performed in 35 patients in the equilibrium phase without fat saturation, with conventional fat saturation, and with fast partial fat saturation. Qualitative and quantitative evaluation demonstrated significantly better vessel visualization with both fat-saturated techniques. The partial fat-saturated technique provided water-specific images within a breath hold, reducing motion artifacts significantly.

    View details for Web of Science ID 000087829500044

    View details for PubMedID 10887265

  • Improved uniformity of aortic enhancement with customized contrast medium injection protocols at CT angiography RADIOLOGY Fleischmann, D., Rubin, G. D., Bankier, A. A., Hittmair, K. 2000; 214 (2): 363-371

    Abstract

    To compare the uniformity of aortoiliac opacification obtained from uniphasic contrast medium injections versus individualized biphasic injections at computed tomographic (CT) angiography.Thirty-two patients with an abdominal aortic aneurysm underwent CT angiography. In 16 patients (group 1), 120 mL of contrast material was administered at a flow rate of 4 mL/sec. In the other 16 patients (group 2), biphasic injection protocols were computed by using mathematic deconvolution of each patient's time-attenuation response to a standardized test injection. Attenuation uniformity was quantified as the "plateau deviation" of enhancement values, which were calculated as the SD of the time-contiguous attenuation values observed during the 30-second scanning period.Group 2 patients received between 77 and 165 mL (mean, 115 mL) of contrast medium. Initial flow rates ranged from 4.1 to 10.0 mL/sec (mean, 6.8 mL/sec) for the first 4-6 seconds; continuing flow rates ranged from 2.0 to 4.8 mL/sec (mean, 3.1 mL/sec) for the remaining 24-26 seconds. The plateau deviation was significantly smaller in group 2 patients (19 HU) versus group 1 patients (38 HU, P <.001).At CT angiography, tailored biphasic injections led to more uniform aortoiliac enhancement, compared with standard uniphasic injections of contrast medium.

    View details for Web of Science ID 000085023400009

    View details for PubMedID 10671582

  • Thoracic venous anatomy delineated by malpositioned central venous catheters on plain chest films JOURNAL OF THORACIC IMAGING Wunderbaldinger, P., Bankier, A. A., Kreuzer, S., Turetschek, K., Fleischmann, D., Herold, C. J. 1999; 14 (4): 286-292

    Abstract

    The aim of this essay was to demonstrate the thoracic venous anatomy as delineated by malpositioned central venous catheters on plain chest radiographs. We therefore used the didactic advantage of clinically inadvertent catheter positions. This approach was chosen to illustrate venous anatomy with plain chest radiographs, and, thereby, to recognize malpositions promptly on the modality with which positions of central venous catheters is routinely performed.

    View details for Web of Science ID 000082932000009

    View details for PubMedID 10524810

  • Evolution of CT findings in patients with cystic fibrosis AMERICAN JOURNAL OF ROENTGENOLOGY Helbich, T. H., Heinz-Peer, G., Fleischmann, D., Wojnarowski, C., Wunderbaldinger, P., Huber, S., Eichler, I., Herold, C. J. 1999; 173 (1): 81-88

    Abstract

    The aim of our study was to assess the evolution of pulmonary CT findings in cystic fibrosis patients.Serial CT examinations were performed in four different follow-up periods on 107 patients with cystic fibrosis. Lung images of the initial and follow-up CT were reviewed and scored for specific morphologic findings. CT findings were correlated with the results of the pulmonary function tests and clinical (Shwachman-Kulczycki) scores.Morphologic changes were minor within the first 18 months of follow-up compared with the period after 18 months. The increase of the overall score was significantly higher in groups with follow-up periods longer than 18 months compared with groups with follow-up periods shorter than 18 months. Various components of morphologic changes contributed to the sequential changes seen on the CT scans. All morphologic changes and the CT scores correlated significantly (p < .0001) with pulmonary function tests and clinical score. CONCLUSION. Serial CT scans allow assessment of the evolution of pulmonary abnormalities in patients with cystic fibrosis. CT seems to have advantages over pulmonary function tests and clinical scoring in the depiction of pulmonary changes over time.

    View details for Web of Science ID 000081010900017

    View details for PubMedID 10397104

  • Mathematical analysis of arterial enhancement and optimization of bolus geometry for CT angiography using the discrete Fourier transform JOURNAL OF COMPUTER ASSISTED TOMOGRAPHY Fleischmann, D., Hittmair, K. 1999; 23 (3): 474-484

    Abstract

    The goal of this work was to develop a clinically applicable mathematical algorithm to analyze and optimize individual arterial enhancement in CT angiography (CTA).Assuming a time-invariant linear system, the discrete Fourier transform was used to calculate the transfer function of the system ("patient function") from the arterial time-attenuation response to a test bolus. The patient function was subsequently used to predict aortic enhancement in five select patients and to calculate optimized biphasic injection protocols in two of these patients undergoing CTA of the abdominal aorta.Arterial time-attenuation curves were accurately predicted in all patients. Optimized biphasic contrast agent injection protocols resulted in uniform aortic enhancement at the predefined level over the entire scanning period in both subjects despite markedly different contrast agent volumes and injection rates used.Fourier analysis of the time-attenuation response to a test bolus is a simple and feasible approach to optimize arterial enhancement in CTA.

    View details for Web of Science ID 000080366000026

    View details for PubMedID 10348458

  • Subjective differentiation of normal and pathological bronchi on thin-section CT: impact of observer training EUROPEAN RESPIRATORY JOURNAL Bankier, A. A., Fleischmann, D., de Maertelaer, V., Kontrus, M., Zontsich, T., Hittmair, K., Mallek, R. 1999; 13 (4): 781-786

    Abstract

    The effect of observer training on sensitivity, specificity and interobserver agreement in the differentiation between normal and pathological bronchi on computed tomography (CT) was studied. The wall thickness of bronchi with normal walls and with pathologically thickened walls were subjectively scored by three independent observers before and after a training period of 2 weeks. Sensitivity, specificity and interobserver agreement were calculated for reading sessions before and after training. Increase and decrease in agreement after training were determined. There was a statistically significant difference (p=0.001) between objectively measured wall thickness of normal and pathological bronchi, both for reference bronchi and for bronchi used for reading sessions. While training increased interobserver agreement, it had no effect on sensitivity (0.46 versus 0.44 after training) and specificity (0.71 versus 0.72 after training) in detecting pathological bronchi. Increased agreement after training was significantly (p=0.001) more frequent than decreased agreement. There is a discrepancy between the effect of training on interobserver agreement and on sensitivity and specificity in the subjective differentiation between normal and pathological bronchi. Interobserver agreement alone is not a reliable indicator of a beneficial effect of training in the evaluation of this parameter.

    View details for Web of Science ID 000080401100014

    View details for PubMedID 10362040

  • Quiz case 5 EUROPEAN JOURNAL OF RADIOLOGY Henk, C., Fleischmann, D., Turetschek, K., Mostbeck, G. 1999; 29 (3): 259-261

    View details for Web of Science ID 000080831900007

    View details for PubMedID 10399612

  • Imaging in intensive care medicine - Techniques, indications, diagnostic signs - Part II INTERNIST Bankier, A., Fleischmann, D., Aram, L., Heimberger, K., Schindler, E., Herold, C. J. 1999; 40 (3): 294-304
  • [Diagnostic imaging in intensive care. Techniques, indications, diagnostic signs--II]. Der Internist Bankier, A., Fleischmann, D., Aram, L., Heimberger, K., Schindler, E., Herold, C. J. 1999; 40 (3): W294-304

    View details for PubMedID 10205755

  • Imaging in intensive care medicine - Techniques, indications, diagnostic signs - Part one INTERNIST Bankier, A., Fleischmann, D., Aram, L., Heimberger, K., Schindler, E., Herold, C. J. 1999; 40 (2): 190-204
  • Contrast optimization in CT angiography RADIOLOGE Hittmair, K., Wunderbaldinger, P., Fleischmann, D. 1999; 39 (2): 93-99

    Abstract

    This paper compares different contrast injection techniques for optimizing vessel contrast in CT angiography (CTA). The optimal vessel contrast shall be defined as constant strong enhancement confined to the scanning interval. This "plateau enhancement" guarantees high-quality CTA images and should therefore be approximated during every CTA examination by an appropriate contrast injection protocol. With well-established injection techniques such as the standard bolus technique (constant uniphasic contrast bolus for all patients) or adjustment of the scan delay, considerable individual differences in the arterial enhancement can be observed, and a nondiagnostic examination or an inefficient use of contrast agent might be the result in a particular patient. Therefore, two sophisticated mathematical models have recently been developed for analyzing the individual enhancement characteristics. These models can be exploited to predict the arterial enhancement for any given intravenous contrast bolus in any patient and to optimize the contrast bolus in order to approach the ideal "plateau enhancement." These techniques have to prove their effectiveness in larger clinical series.

    View details for Web of Science ID 000079005900001

    View details for PubMedID 10093834

  • [Diagnostic imaging in intensive care medicine. Techniques, indications, diagnostic signs--I]. Der Internist Bankier, A., Fleischmann, D., Aram, L., Heimberger, K., Schindler, E., Herold, C. J. 1999; 40 (2): W190-204

    View details for PubMedID 10097978

  • Imaging in intensive care medicine. Techniques, indications, diagnostic signs: part II RADIOLOGE Bankier, A., Fleischmann, D., Aram, L., Heimberger, K., Schindler, E., Herold, C. J. 1998; 38 (12): 1089-1099

    View details for Web of Science ID 000077910300018

    View details for PubMedID 9931987

  • [Imaging in intensive care. Methods, indications, diagnostic signs. I]. Der Radiologe Bankier, A., Fleischmann, D., Aram, L., Heimberger, K., Schindler, E., Herold, C. J. 1998; 38 (11): 972-986

    View details for PubMedID 9861660

  • Radiographic findings in patients with acquired immunodeficiency syndrome, pulmonary infection, and microbiologic evidence of Mycobacterium xenopi JOURNAL OF THORACIC IMAGING Bankier, A. A., Stauffer, F., Fleischmann, D., Kreuzer, S., Strasser, G., Mossbacher, U., Mallek, R. 1998; 13 (4): 282-288

    Abstract

    The authors studied radiographs and clinical histories of 29 patients with acquired immunodeficiency syndrome, symptoms of pulmonary infection, and simultaneous microbiologic evidence of Mycobacterium xenopi in the respiratory tract. The presence, nature, and distribution of radiographic abnormalities were determined and analyzed in accord with clinical information. In 26 (90%) patients, M. xenopi was the only microorganism that could be isolated. Chest radiographs were normal in 13 patients (45%) and abnormal in 16 patients (55%). Radiographic abnormalities were bilateral in 94% of cases and predominantly involved the lower lobes. Patchy peribronchial opacities (44%) and miliary nodules (24%) were the most common abnormalities. Reticular opacities and parenchymal consolidation were seen in 12% of patients. Pleural effusion was seen in 18% of patients. No patients had cavitations or adenopathy. There was no statistically significant difference regarding the mean age (38.7+/-7.3 years vs. 40.2+/-11.0 years), the duration of clinically evident human immunodeficiency virus infection (2.7+/-1.2 years vs. 2.8+/-1.4 years), and the mean of CD4 cell counts (50.6+/-15.3 cells/ml vs. 47.4+/-15.9 cells/ml) between the patients with and without abnormalities on chest radiographs. In patients with acquired immunodeficiency syndrome, pulmonary infection, and simultaneous microbiologic evidence of M. xenopi, chest radiographs can be normal in a substantial number of cases. When radiographic abnormalities are present, they differ from those seen in patient not infected with the human immunodeficiency virus who had pulmonary infection caused by M. xenopi and from patients with acquired immunodeficiency syndrome and pulmonary infection with nontuberculous mycobacteria other than M. xenopi. Although these findings are not specific, they may be of importance in the imaging of patients with acquired immunodeficiency syndrome, notably in areas where M. xenopi is endemic.

    View details for Web of Science ID 000076448600007

    View details for PubMedID 9799136

  • [Spiral CT angiography in diagnosis of acute pulmonary embolism. What factors modify implementation of standard algorithms?]. Der Radiologe Bankier, A., Herold, C. J., Fleischmann, D., Janata-Schwatczek, K. 1998; 38 (4): 248-255

    Abstract

    Debate about the potential implementation of Spiral-CT in diagnostic algorithms of pulmonary embolism are often focussed on sensitivity and specificity in the context of comparative methodologic studies. We intend to investigate whether additional factors might influence this debate.On the basis of the current literature and of own experience we study the influence of factors such as availability, acceptance, patient-outcome, and cost effectiveness-studies on the potential implementation of Spiral-CT in diagnostic algorithms of pulmonary embolism. This information is analyzed together with data from comparative methodologic studies.The factors availability, acceptance, patient-outcome, and cost-effectiveness-studies do have substantial influence on the implementation of Spiral-CT in the diagnostic algorithms of pulmonary embolism. Incorporation of these factors into the discussion might lead to more flexible and more patient-oriented algorithms for the diagnosis of pulmonary embolism.Availability of equipment, acceptance among clinicians, patient-outcome, and cost-effectiveness evaluations should be implemented into the debate about potential implementation of Spiral-CT in routine diagnostic imaging algorithms of pulmonary embolism.

    View details for PubMedID 9622818

  • Comparison of T2-weighted and fluid-attenuated inversion-recovery fast spin-echo MR sequences in intracerebral AIDS-associated disease AMERICAN JOURNAL OF NEURORADIOLOGY Thurnher, M. M., Thumher, S. A., Fleischmann, D., Steuer, A., Rieger, A., Helbich, T., Trattnig, S., Schindler, E., Hittmair, K. 1997; 18 (9): 1601-1609

    Abstract

    To compare the value of fast fluid-attenuated inversion-recovery (FLAIR) with T2-weighted fast spin-echo MR imaging in the detection of acquired immunodeficiency virus (AIDS)-related lesions of the brain.Forty-four human immunodeficiency virus (HIV)-positive patients were examined with both sequences on either a 1.0-T or a 1.5-T MR system. The number, size, location, and conspicuity of the lesions were evaluated by two independent observers. Contrast ratios between lesions and normal brain/cerebrospinal fluid were determined, and contrast-to-noise ratios were calculated.FLAIR was found to be superior to T2-weighted fast spin-echo in detection of small lesions and of lesions located in cortical/subcortical regions and deep white matter. The two techniques were equal in delineation of lesions larger than 2 cm and for lesions located in the basal ganglia and posterior fossa. In 24 patients, more lesions were detected with the FLAIR fast spin-echo technique. Lesion/cerebrospinal fluid contrast ratios and contrast-to-noise ratios were significantly higher for the FLAIR fast spin-echo sequences than for the T2-weighted fast spin-echo sequences.FLAIR allows early detection of small lesions in subcortical and cortical locations, especially in HIV encephalitis. Because of its improved lesion detection rate and greater overall lesion conspicuity, we believe FLAIR is useful in the evaluation of subtle changes in the brains of AIDS patients with central nervous system disease, and could even replace the T2-weighted fast spin-echo technique.

    View details for Web of Science ID A1997YC79700001

    View details for PubMedID 9367306

  • Progressive multifocal leukoencephalopathy in AIDS: initial and follow-up CT and MRI NEURORADIOLOGY Thurnher, M. M., Thurnher, S. A., Muhlbauer, B., Hainfellner, J. A., Steuer, A., Fleischmann, D., Trattnig, S., Budka, H., Schindler, E. 1997; 39 (9): 611-618

    Abstract

    We sought to determine the value of follow-up CT and MRI in patients with acquired immuno-deficiency syndrome (AIDS) and progressive multifocal leukoencephalopathy (PML). We reviewed 50 CT and 19 MRI examinations performed in 21 biopsy- or autopsy-proven cases of PML; 17 patients had follow-up examinations (mean time 5.9 weeks). The radiological examinations were correlated with pathological findings at autopsy. On initial imaging studies, 73 lesions were found. On follow-up, the most striking feature was rapid progression in both size and number of the lesions (from a mean of 3.2 to 6.9 per patient). One third of the patients showed increasing mass effect. A central area suggesting necrosis, of variable size, was found in 12/16 patients. Autopsy revealed macroscopic necrotic changes in the lesions in 11/16 patients.

    View details for Web of Science ID A1997XX51400001

    View details for PubMedID 9335057

  • Pulmonary hypertension and cor pulmonale RADIOLOGE Henk, C. B., Gabriel, H., Fleischmann, D., Schoder, M., Mostbeck, G. H. 1997; 37 (5): 388-401

    Abstract

    Pulmonary hypertension is a severe disorder of the pulmonary circulation and occurs in a variety of vascular and parenchymal lung diseases. It leads to volume and/or pressure overload of the right ventricle and finally to right heart failure. Pulmonary vascular diseases such as chronic pulmonary embolism cause a drastic increase in pulmonary vascular resistance, which results in extremely high pulmonary artery pressures that can even reach systemic levels. On the other hand, moderate pulmonary hypertension can also occur in chronic obstructive and restrictive lung diseases. For a long time, the diagnosis of pulmonary hypertension and cor pulmonale was based upon findings in echocardiography and right heart catheterization. Today modern imaging techniques allow the radiologist to assess right ventricular and pulmonary artery morphology and function. The application of spiral CT, electron-beam CT and MRT permits the diagnosis and differential diagnosis of pulmonary hypertension and also the evaluation and follow-up of underlying vascular or parenchymal lung disorders. In addition, quantification of right ventricular function and calculation of pulmonary hemodynamic parameters are possible.

    View details for Web of Science ID A1997XN77700007

    View details for PubMedID 9312782

  • Radiographic detection of intrabronchial malpositions of nasogastric tubes and subsequent complications in intensive care unit patients INTENSIVE CARE MEDICINE Bankier, A. A., WIESMAYR, M. N., Henk, C., Turetschek, K., Winkelbauer, F., Mallek, R., Fleischmann, D., Janata, K., Herold, C. J. 1997; 23 (4): 406-410

    Abstract

    The aim of our study was to illustrate the radiographic spectrum of the intrabronchial malposition of nasogastric tubes and subsequent complications, and to discuss the role of radiography in the detection of such malpositions.Retrospective clinical investigation.Tertiary care university teaching hospital.We reviewed chest radiographs of 14 intensive care patients with nasogastric tubes malpositioned in the tracheobronchial tree. The site and anatomic location of the malposition were recorded. Complications due to tube malpositioning were monitored on follow-up radiographs and on computed tomographic examinations, which were available in 4 patients.Nine of 14 nasogastric tubes were inserted in the right and 5 in the left tracheobronchial tree. Tube tips were malpositioned in the lower lobe bronchi (50%), the intermediate bronchus (36%), and the main bronchi (14%). There was perforation of the bronchial system with subsequent pneumothorax in 4 patients. In 4 other patients, pneumonia developed at the former site of the malpositioned tube tip. Radiographic detection of nasogastric tube malpositioning was prompt in 9 patients and delayed in 5 patients.Whereas clinical signs of nasogastric tube malpositioning in intensive care patients may be absent or misleading, chest radiography can accurately detect nasogastric tube malpositions in the tracheobronchial tree, may prevent complications, and avoid the use of further costly or invasive diagnostic techniques.

    View details for Web of Science ID A1997WX30400008

    View details for PubMedID 9142579

  • Radiographically occult scaphoid fractures: Value of MR imaging in detection RADIOLOGY Breitenseher, M. J., Metz, V. M., Gilula, L. A., Gaebler, C., Kukla, C., Fleischmann, D., Imhof, H., Trattnig, S. 1997; 203 (1): 245-250

    Abstract

    To evaluate the diagnostic value of magnetic resonance (MR) imaging in patients with clinical suspicion of scaphoid fractures and normal initial plain radiographs.MR imaging was performed within 7 days after trauma in 42 patients with clinical suspicion of scaphoid fractures and normal plain radiographs. T1-weighted spin-echo, T2*-weighted gradient-echo, and short inversion time inversion-recovery (STIR) sequences were performed. MR images were evaluated independently by two radiologists. Six-week follow-up radiographs were used as a standard to diagnose fractures.MR imaging depicted occult fractures of the scaphoid bone in 14 patients (33%), the capitate bone in four (10%), the trapezium in one (2%), and the distal radius in two (5%). All wrist fractures were detected with a combination of STIR and T1-weighted spin-echo sequences. The sensitivity and specificity for detection of radiographically occult fractures of the wrist were 100% each for the first and 95% and 100%, respectively, for the second radiologist with an almost perfect interobserver agreement (K = 0.953).MR imaging has a high sensitivity for detection of fractures of the scaphoid bone and wrist not evident on plain radiographs and may enable early diagnosis and treatment.

    View details for Web of Science ID A1997WP24100042

    View details for PubMedID 9122402

  • Severity assessment of acute pulmonary embolism with spiral CT: Evaluation of two modified angiographic scores and comparison with clinical data JOURNAL OF THORACIC IMAGING Bankier, A. A., Janata, K., Fleischmann, D., Kreuzer, S., Mallek, R., Frossard, M., Domanovits, H., Herold, C. J. 1997; 12 (2): 150-158

    Abstract

    Spiral computed tomography (CT) has shown promising results in the detection of acute pulmonary embolism. The aim of this study was to investigate whether the severity of acute pulmonary embolism could be quantitatively assessed with spiral CT examinations and to test the potential clinical impact of this information. In a consecutive series of 123 patients screened with spiral CT for suspected acute pulmonary embolism, 31 patients (25%) had evidence of emboli. The severity of pulmonary arterial obstruction in those 31 spiral CT examinations was evaluated by two independent observers using angiographic scores previously described by Walsh (29) and Miller (30), adapted to the needs of spiral CT. Clinical patient subgroups were defined according to oxygen saturation, heart rate, and echocardiographic signs of right ventricular strain. CT severity scores were then correlated to each other and to clinical parameters using the Spearman rank test. Interobserver agreement was calculated using the analysis of variance. Both modified Walsh and Miller scores were readily reproducible and showed interobserver agreements of 0.85 and 0.96, respectively (p = 0.001). Patients with mild and marked clinical abnormalities showed statistically significant differences between CT severity scores. Differences between severity scores of patients with moderate and marked clinical abnormalities were somewhat significant. No significant mean severity score differences were seen between patients with mild and moderate clinical abnormalities. Although correlations of severity scores and detailed clinical parameters within the defined subgroups were moderate to poor, threshold scores greater than 10 (Miller) and greater than 11 (Walsh) always indicated marked clinical abnormalities. The modified scores presented in this study constitute a readily reproducible method for the quantitative assessment of acute pulmonary embolism severity on spiral CT examinations.

    View details for Web of Science ID A1997XB63900012

    View details for PubMedID 9179827

  • MRI of the sinus tarsi in acute ankle sprain injuries JOURNAL OF COMPUTER ASSISTED TOMOGRAPHY Breitenseher, M. J., Haller, J., Kukla, C., Gaebler, C., Kaider, A., Fleischmann, D., Helbich, T., Trattnig, S. 1997; 21 (2): 274-279

    Abstract

    Our goal was to evaluate the visibility and incidence of traumatic abnormalities of the sinus tarsi in patients with acute ankle sprain injuries and compare these findings with the extent of lateral ankle ligament injuries on MRI.Sixty athletically active patients (aged 18-45 years) with recent inversion trauma (< or = 7 days) underwent MRI. Replacement of fat tissue in the sinus tarsi was recorded. Inter/intraobserver agreement was calculated (kappa-statistics). Injuries of the three lateral ligaments, evaluated by MRI, were graded according to partial (1 point) or complete (2 points) tears for each of three lateral ligaments (together 0-6 points) and were compared with sinus tarsi abnormalities.In 26 patients (43%), replacement of sinus tarsi fat tissue was depicted by MRI. Inter/intraobserver agreement for MR changes of the sinus tarsi was good to moderate (kappa = 0.675/0.584). Grade of lateral ankle ligament injury showed a statistically significant difference (p = 0.033) between the two sinus tarsi groups (normal/abnormal).Acute ankle sprain injuries, evaluated by MRI, are associated with acute abnormalities of the sinus tarsi in 43% of patients and correlate with the extent of lateral ankle ligament tears.

    View details for Web of Science ID A1997WM65500020

    View details for PubMedID 9071300

  • [Diagnostic imaging within the scope of lung transplantation]. Der Radiologe Bankier, A. A., Hörmann, M., Aram, L., Fleischmann, D. 1997; 37 (3): 211-219

    Abstract

    Recent progress in both surgical techniques and therapeutic medication of immunosupression have made lung transplantation a promising option for patients with untreatable diseases of the lung parenchyma. Because preoperatively and postoperatively diagnostic imaging has crucial importance for patient management and clinical decision making we aim to describe imaging features of frequent pathologies in patients after lung transplantation.We reviewed radiological examinations of patients after lung transplantation performed at our institution over a period of four years, and exemplary cases were selected for presentation. Our interest was focussed on both conventional and CT-imaging of postoperative alterations, infections, organ rejection, and pathologies of the airways. Moreover, post-biopsy alterations and lymphoproliferative disorders were documented. Together with clinical information we aimed to give a concise description of specific pathologic entities. Also, the diagnostic impact of more recent techniques such as spiral-CT and thin-section CT should be discussed.In cases of early postoperative pathologies and in infections conventional radiography is diagnostically reliable when interpreted together with clinical information. In cases of acute or chronic organ rejection, of lymphoproliferative disorders, of diseases of central or small airways, and for the choice of an appropriate biopsy site, CT has proved to be a valuable imaging modality. Spiral-CT allows airway volumetry in cases of strictures or dehiscence, thin-section CT enables assessment of subtle parenchymal pathologies, notably in cases of chronic organ rejection.The radiographic findings described below represent specific pathogenetic entities in lung-transplant patients (postoperative alterations, infections, posttransplant lymphoproliferative disorders). Their accurate recognition will have a positive impact on the further clinical history. In the near future, more sophisticated CT techniques should widen our pathogenetic knowledge of alterations in transplanted lungs.

    View details for PubMedID 9182310

  • Azygos arch cannulation by central venous catheters: Radiographic detection of malposition and subsequent complications JOURNAL OF THORACIC IMAGING Bankier, A. A., Mallek, R., WIESMAYR, M. N., Fleischmann, D., Kranz, A., Kontrus, M., Knapp, S., Winkelbauer, F. W. 1997; 12 (1): 64-69

    Abstract

    The aim of this study was to determine the frequency of radiographically evident central venous catheter misplacement in the azygos arch and to analyze whether the frequency of azygos arch cannulation is dependent on the anatomical site of catheter insertion. We reviewed 1,287 postprocedural examinations and 3,441 follow-up examinations. Catheters had been inserted through the left (6%) or right (15%) internal jugular veins and through the left (32%) or right (46%) subclavin veins. Radiographs were analyzed for possible catheter malposition in the azygos arch and for complications related to this malposition. Catheter malposition in the azygos arch was seen on 16/1,287 (1.2%) postprocedural radiographic examinations. Of the 16 malpositioned catheters, 11 (69%) had been inserted in the left subclavian vein, three (19%) in the left jugular vein, two (12%) in the right subclavian vein, and none (0%) in the right jugular vein. There was a statistically significant difference in the frequency of azygos arch cannulation between left- and right-sided catheters (p = 0.001). All complications consisted of venous perforations and were seen in three of 16 cases (19%). Azygos arch cannulation is a rare but hazardous central venous catheter malposition that occurs early after catheter insertion and carries a substantial risk for complication. The risk for azygos arch cannulation is substantially increased if catheters are inserted in left-sided veins. Because of the severity of subsequent complications, radiologists should be vigilant in the detection of this rare malposition.

    View details for Web of Science ID A1997WA70200010

    View details for PubMedID 8989762

  • Imaging procedure in intensive care medicine .2. Techniques, indications, diagnostic signs ANAESTHESIST Bankier, A. A., Fleischmann, D., Aram, L., Heimberger, K., Schindler, E., Herold, C. J. 1996; 45 (9): 869-880

    View details for Web of Science ID A1996VK84900016

    View details for PubMedID 8967607

  • Deep venous thrombosis of the lower extremity efficacy of spiral CT venography compared with conventional venography in diagnosis RADIOLOGY Baldt, M. M., Zontsich, T., Stumptlen, A., Fleischmann, D., Schneider, B., Minar, E., Mostbeck, G. H. 1996; 200 (2): 423-428

    Abstract

    To compare the efficacy of spiral computed tomographic (CT) venography with conventional venography in the diagnosis of suspected deep venous thrombosis (DVT).In a prospective study, 52 consecutive patients with clinically suspected unilateral or bilateral DVT were studied with CT venography and conventional venography. In cases in which conventional venographic findings were inconclusive, color-coded duplex sonography and follow-up examinations were performed to make a final diagnosis. CT venography of both extremities covered a 100-cm section from the ankle to the inferior vena cava (IVC). Contrast material diluted with saline was injected in a dorsal vein of each foot. CT and conventional venography (including color-coded duplex sonography and follow-up findings) were correlated for three venous regions for each patient.Correlation was excellent between CT and conventional venographic findings in the detection of DVT. The sensitivity of CT venography was 100% (confidence interval: 0.92, 1.00), specificity was 96% (confidence interval: 0.84, 0.98), positive predictive value was 91%, and negative predictive value was 100%. CT venography more clearly demonstrated thrombus extension of DVT into the pelvic veins and IVC than conventional venography alone.CT venography is a valuable tool in the diagnosis of DVT. Compared with conventional venography, CT requires use of 80% less contrast material.

    View details for Web of Science ID A1996UY07800023

    View details for PubMedID 8685336

  • [Pleural and pulmonary changes within the scope of rheumatoid arthritis]. Der Radiologe Bankier, A. A., Fleischmann, D., Kiener, H. P., WIESMAYR, M. N., Herold, C. J. 1996; 36 (8): 637-645

    Abstract

    Pulmonary complications caused by rheumatoid arthritis are a clinically relevant aspect of this chronic arthropathy. Those complications can involve all parts of the thorax, including the lung parenchyma, the pleura, and the thoracic cage. The most common complications are necrobiotic nodules, pleural abnormalities, Caplan's syndrome, parenchymal fibrosis, bronchiolitis obliterans, and iatrogenic damage of lung the parenchyma. This article reviews pulmonary abnormalities induced by rheumatoid arthritis and their clinical and radiological findings. In addition, the role of different imaging modalities in the diagnostic work-up of pulmonary complications caused by rheumatoid arthritis is discussed.

    View details for PubMedID 8975281

  • [Imaging in intensive care medicine. I. Techniques, indications, diagnostic signs]. Der Anaesthesist Bankier, A. A., Fleischmann, D., Aram, L., Heimberger, K., Schindler, E., Herold, C. J. 1996; 45 (8): 769-786

    View details for PubMedID 8967593

  • [Calcium in the lung or: it might not always be tuberculosis]. Der Radiologe Henk, C. B., Liskutin, J., Fleischmann, D., Mostbeck, G. H. 1996; 36 (7): 534-542

    Abstract

    Pulmonary calcifications are a frequent finding in CT examinations of the chest. In many cases, characteristic CT morphology and distribution of pulmonary and mediastinal calcifications may lead to a straightforward specific diagnosis of the underlying disease. In that respect, calcifications are often the residual finding of previous infections. Less often, they may be due to neoplasms, metabolic disorders, occupational exposure or previous therapy. This review focuses on the etiology, pathogenesis and morphological CT features of pulmonary calcifications. A knowledge of the technical aspects of CT imaging is required to verify calcifications and avoid pitfalls.

    View details for PubMedID 8927723

  • [Computerized tomography of AIDS associated thoracic diseases]. Der Radiologe Bankier, A. A., Fleischmann, D., Kontrus, M., WIESMAYR, M. N., Herold, C. J. 1996; 36 (7): 543-549

    Abstract

    Pulmonary infections and tumors are a major cause of death in patients with AIDS. The combination of clinical, radiological, laboratory, and pathohistological data helps to narrow the spectrum of differential diagnoses or even allows a specific diagnosis in many patients. Nevertheless, an accurate diagnosis should be obtained as soon as possible during the clinical course of the illness to initiate treatment in time. Computed tomography (CT) has proven to provide promising results in the diagnosis of AIDS-related thoracic diseases. The aim of this paper was to demonstrate the diagnostic capacities of CT in the context of particular AIDS-related thoracic pathologies. Additional information on the spectrum of pathological agents and on differential diagnostic signs is summarized.

    View details for PubMedID 8927724

  • [Spiral-CT [corrected] in chronic lung thromboembolism. Der Radiologe Kontrus, M., Bankier, A. A., Fleischmann, D., Winkelbauer, F. W., Klepetko, W., Lang, I., WIESMAYR, M. N., Herold, C. J. 1996; 36 (6): 496-502

    Abstract

    Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare result of recurrent pulmonary embolism and is treated by pulmonary thromboendarterectomy. Knowledge of the exact location of the thrombi is necessary in planning this operation. To date, pulmonary, angiography is the diagnostic imaging gold standard. Since the introduction of spiral CT excellent vascular opacification of the pulmonary arteries has become feasible, and thrombi in the pulmonary arteries can be visualized directly. Spiral CT is superior to angiography in demonstrating thrombi in the central pulmonary arteries, whereas angiography proves superior to CT in the evaluation of abnormalities within segmental arteries. The sensitivity of spiral CT in confirming the diagnosis of CTEPH is reported to be more than 90%. According to the literature and based on our own results, the decision concerning operability is possible on the basis of spiral CT images in more than 80% of patients with CTEPH. Spiral CT as a non-invasive tool may be used for CTEPH screening, for postoperative follow-up after pulmonary thrombendarterectomy and, combined with pulmonary angiography, to optimize operation planning.

    View details for PubMedID 8767120

  • Bronchial wall thickness: Appropriate window settings for thin-section CT and radiologic-anatomic correlation RADIOLOGY Bankier, A. A., Fleischmann, D., Mallek, R., Windisch, A., Winkelbauer, F. W., Kontrus, M., Havelec, L., Herold, C. J., Hubsch, P. 1996; 199 (3): 831-836

    Abstract

    To analyze the influence of computed tomographic (CT) window settings on bronchial wall thickness and to define appropriate window settings for its evaluation.Three inflation-fixed lungs were scanned with a section thickness of 1.5 mm by using a high-spatial-frequency algorithm. Wall thickness in 10 bronchial specimens was measured with planimetry. Window centers were altered in a range of -200 to -900 HU and window widths in a range of 400-1,500 HU. Relative and absolute differences between CT and planimetric values were calculated. CT and planimetric measures were correlated. Inter- and intraobserver variabilities were determined.Window widths less than 1,000 HU resulted in a substantial overestimation of bronchial wall thickness, whereas widths greater than 1,400 HU resulted in an underestimation of bronchial wall thickness. There was no interaction between "width" and "center" regarding their influence on bronchial walls (F = 0.23; P = .99). Correlation between CT and planimetry was statistically significant (r = .85; P = .0001). Differences between the two observers were not statistically significant; results of the measurements of the two observers correlated well (r = .97; P = .001).Bronchial wall thickness on thin-section CT scans should be evaluated with window centers between -250 and -700 HU and with window widths greater than 1,000 HU. Other than window settings, notably window widths less than 1,000 HU, can lead to substantial artificial thickening of bronchial walls.

    View details for Web of Science ID A1996UL52600043

    View details for PubMedID 8638013

  • [Spiral CT in acute pulmonary embolism]. Der Radiologe Fleischmann, D., Kontrus, M., Bankier, A. A., WIESMAYR, M. N., Janata-Schwatczek, K., Herold, C. J. 1996; 36 (6): 489-495

    Abstract

    Pulmonary embolism is a frequent and potentially life-threatening event with uncharacteristic clinical manifestations. Diagnosis is commonly established by ventilation/perfusion scintigraphy and pulmonary angiography. Both methods, however, carry substantial drawbacks. Therefore, clinicians claim that there is a need for an accurate and non-invasive diagnostic modality. Spiral CT of the pulmonary arteries is a recent modality, that allows reliable visualization of emboli in pulmonary arteries up to fourth-order branches. This paper reviews the technical aspects, typical findings and diagnostic pitfalls of this recent technique. The potential role of spiral CT in the screening of patients with suspected pulmonary embolism is discussed and selected cases are presented.

    View details for PubMedID 8767119

  • [Radiological diagnosis of emphysema prior to volume-reduction surgery]. Wiener medizinische Wochenschrift Kontrus, M., Bankier, A. A., Fleischmann, D., Herneth, A., Herold, C. J. 1996; 146 (23): 587-591

    Abstract

    Conventional chest X-ray and computed tomography as the main diagnostic tools are demonstrated with their possibilities in the diagnosis of emphysema. They were correlated with lung function tests and pathology in literature. Volume reduction surgery as a new operation technique for patients with advanced emphysema needs different radiologic evaluation. The radiologic possibilities for evaluation of operability of these patients and for operation planning will be discussed.

    View details for PubMedID 9064919

  • Lung metastases EUROPEAN RADIOLOGY Herold, C. J., Bankier, A. A., Fleischmann, D. 1996; 6 (5): 596-606

    Abstract

    The lungs are among the most prominent target organs for metastatic disease. Most frequently, lung metastases originate from cancers of the head and neck, breast, stomach, pancreas, kidney, bladder, the male and female genitourinary tract, and sarcomas. Plain chest radiography is typically the modality used for detection and therapeutic monitoring; however, the use of CT for these purposes is becoming more frequent. Currently, spiral CT appears to be the most sensitive imaging technique in the identification of metastases, because it detects a higher number of pulmonary nodules compared to other techniques. Pulmonary metastatic disease manifests itself by the presence of pulmonary nodules, lymphangitic carcinomatosis, endobronchial tumors, and pleural involvement. Nevertheless, the differential diagnosis is an important consideration, particularly in patients with solitary pulmonary nodules, systemic disorders, and signs or symptoms indicative of infection. The role of the radiologist involves the identification of metastatic disease, monitoring of response to therapy, and the use of invasive procedures when the differential diagnosis indicates the need for biopsy and histopathologic proof. The radiologist must be aware of the impact of his diagnosis on patient management and should be familiar with oncologic strategies as well as the terminology used to characterize tumor response. In future, the role of imaging may further expand due to the increased sensitivity in lesion detection, increased specificity in lesion (tissue) characterization using MR imaging imaging, and reduced radiation exposure.

    View details for Web of Science ID A1996VM42400002

    View details for PubMedID 8934121

  • [Ultra-short turbo-spin echo in comparison with turbo-spin echo. Possible applications in the musculoskeletal system]. Der Radiologe Breitenseher, M., Kontaxis, G., Fleischmann, D., RAND, T. H., Imhof, H., Trattnig, S. 1995; 35 (12): 981-983

    Abstract

    Ultrashort turbo spin-echo sequence (TSE) has the advantage of shorter scan times, minimizing motion artifacts, but has the disadvantage of a lower signal-to-noise ratio and suffers from different artifacts. T2-weighted ultrashort TSE (echo train 24) and TSE (echo train 11) were compared in degenerative lesions of the spine (n = 9) and ligamentous lesions associated with sprained ankle injuries (n = 5). The imaging quality of ultrashort TSE was very similar to TSE. There was no difference in diagnostic reliability with ultrashort TSE compared to TSE in the spine or ankle. With regard to contrast properties a higher signal intensity of fatty bone marrow was obtained with ultrashort TSE, with consecutive lower contrast between fluid and edema on the one hand and fatty tissue on the other.

    View details for PubMedID 8584642

  • DISCRETE LUNG INVOLVEMENT IN SYSTEMIC LUPUS-ERYTHEMATOSUS - CT ASSESSMENT RADIOLOGY Bankier, A. A., Kiener, H. P., WIESMAYR, M. N., Fleischmann, D., Kontrus, M., Herold, C. J., GRANINGER, W., Hubsch, P. 1995; 196 (3): 835-840

    Abstract

    To study the computed tomographic (CT) appearance of early lung involvement in systemic lupus erythematosus (SLE).In a prospective study, 48 patients with serologically confirmed SLE but no prior clinical evidence of lung involvement underwent chest radiography, CT, and lung function tests. Radiographs and CT scans were compared, and CT scans were evaluated for signs suggestive of parenchymal and pleural disease. Extent and distribution of disease were determined. CT findings were correlated with clinical and functional data.Of 45 patients with normal chest radiographs, 17 (38%) had abnormal CT findings. Extent of disease was statistically significantly correlated with duration of clinical history (r = .93) and decreased single-breath diffusing capacity for carbon monoxide (r = .8) and ratio of forced expiratory volume in 1 second to forced vital capacity (r = .77).CT is superior to chest radiography for detection of functionally relevant pulmonary disease and is an important adjunct in early assessment of SLE.

    View details for Web of Science ID A1995RQ24300041

    View details for PubMedID 7644652

  • ULTRASOUND IMAGING FOR STELLATE GANGLION BLOCK - DIRECT VISUALIZATION OF PUNCTURE SITE AND LOCAL-ANESTHETIC SPREAD - A PILOT-STUDY REGIONAL ANESTHESIA Kapral, S., Krafft, P., Gosch, M., Fleischmann, D., Weinstabl, C. 1995; 20 (4): 323-328

    Abstract

    Stellate ganglion block (SGB) inhibits sympathetic innervation and is a common treatment for reflex sympathetic dystrophy. During the positioning of the needle, there is a risk of injury to the adjacent structures. The aim of the study was to develop an ultrasonographic imaging technique for the performance of SGB.Twelve patients (ASA I-II) underwent SGB first by using the blind standard technique (group A: 8 mL bupivacaine 0.25%) and a second time by using an ultrasonographic imaging technique (group B: 5 mL bupivacaine 0.25%). In group B a 10 MHz ultrasound scanning probe was used to identify the anatomic structures and to guide the needle toward the transverse process of C6.Stellate ganglion block was satisfactory in 11 of 12 attempts by the blind technique. Ultrasonographic guidance (group B) resulted in a complete block in all patients. Onset of block was observed within 10 minutes in only 10 of 12 group A patients, while all patients in group B exhibited an adequate block after 10 minutes. During the imaging technique, the needle was inserted to an average depth of 22 +/- 3 mm and the injection of 5 mL bupivacaine resulted in an anesthetic depot with a mean diameter of 14 +/- 3 mm. Distance from the depot to the vagal nerve was 5 +/- 3 mm and 5 +/- 4 mm to the root of C6. All patients (n = 4) with a distance of < 1 mm between anesthetic depot and the root of C6 developed paresthesia within the corresponding cutaneous segment. Blind technique resulted in hematoma formation in three study patients, with no hematoma occurring during imaging technique.Ultrasonographic guided SGB may improve safety and allows the visualization of the local anesthetic depot. Studying the local anesthetic spread might allow the avoidance of side effects as well as typical complications of SGB.

    View details for Web of Science ID A1995RL21700008

    View details for PubMedID 7577781

  • UPDATE - ABDOMINAL TUBERCULOSIS - UNUSUAL FINDINGS ON CT CLINICAL RADIOLOGY Bankier, A. A., Fleischmann, D., WIESMAYER, M. N., Putz, D., Kontrus, M., Hubsch, P., Herold, C. J. 1995; 50 (4): 223-228

    Abstract

    To update our knowledge of abdominal tuberculosis as manifested on computed tomography (CT), we reviewed the CT scans of 12 patients with proven abdominal tuberculosis. The nature, range and extent of abdominal involvement was determined. The CT findings were compared to those reported in the literature. The aetiologic agent was Mycobacterium tuberculosis in all patients. One patient had an increased risk because of AIDS. In nine patients, tuberculosis was limited to the abdomen, and three patients had previously unknown thoracic tuberculous disease. Characteristic features in our patients included low density ascites and uncommon patterns of adenopathy. Findings reported to be typical in abdominal tuberculosis were present in only five of our 12 patients. Unusual findings in our patients included solitary and multiple pelvic, adrenal, splenic and hepatic lesions. In six of 12 patients, those findings mimicked malignancy. We conclude that knowledge and early recognition of these unusual manifestations of abdominal tuberculosis should help to optimize clinical management of the disease and avoid misdiagnosis.

    View details for Web of Science ID A1995QT14400004

    View details for PubMedID 7729118

  • POSITION OF JUGULAR OXYGEN-SATURATION CATHETER IN PATIENTS WITH HEAD TRAUMA - ASSESSMENT BY USE OF PLAIN FILMS AMERICAN JOURNAL OF ROENTGENOLOGY Bankier, A. A., Fleischmann, D., Windisch, A., Germann, P., PETRITSCHEK, W., WIESMAYR, M. N., Hubsch, P. 1995; 164 (2): 437-441

    Abstract

    The purpose of this study was to establish a plain radiographic technique for the assessment of the position of a jugular oxygen saturation catheter in patients with head trauma.In the experimental study, jugular oxygen saturation catheters were introduced into the internal jugular veins of four cadavers. Correct positioning of the catheter tips was monitored by CT. Concurrent anteroposterior radiographs of the skulls were obtained with the tubes angled in a transverse plane and in a sagittal plane at intervals of 5 degrees and within a total range of 70 degrees for each plane. Three radiologists judged the visibility of the catheter tips and measured the distance of the catheter tips to previously determined bony landmarks of the skull. Then, preliminary radiologic criteria for correct positioning of the catheters were defined. In the clinical study, we prospectively evaluated radiographs for 32 patients who received jugular oxygen saturation catheters. Eleven patients had digital radiographs done, and 21 patients had radiographs with a conventional screen film system done. Radiographs were analyzed for consistency of findings with the experimental results and for consistency of the suspected catheter position with laboratory data.Results of the cadaveric study showed that catheter position is best assessed on strict anteroposterior radiographs with the orbitomeatal-basal line perpendicular to the plane of the film. A correctly positioned catheter tip should lie cranial to a line extending from the atlantooccipital joint space and caudal to the lower margin of the orbit. The catheter tip also should lie cranial to a line connecting the tips of the mastoid processes, with a catheter tip-to-line distance averaging 20% of the overall distance between the tips of the mastoid processes. According to these criteria, the catheter was properly positioned in 26 of 32 patients. In three patients, the catheter obviously was improperly positioned. Catheter position was equivocal in three other patients; in two of these patients, the catheter was looped within the internal jugular vein. Whereas for all 26 patients with properly positioned catheters values for jugular venous oxygen saturation were congruent with other laboratory data, incongruent saturation values were recorded for five of the six patients with equivocally or obviously improperly positioned catheters.Accurate assessment of the position of a jugular oxygen saturation catheter can be made by use of specific bony landmarks seen on anteroposterior radiographs of the skull.

    View details for Web of Science ID A1995QC79400033

    View details for PubMedID 7839985

  • [Right aortic arch simulates mediastinal tumor: diagnosis with spiral CT]. Aktuelle Radiologie Bankier, A., Fleischmann, D., WIESMAYR, M., Hübsch, P. 1995; 5 (1): 70-72

    Abstract

    We report the case of a patient with right aortic arch (type III) mimicking a mediastinal tumor. We discuss the radiological findings together with their embryologic correlations, and emphasize the role of spiral-CT in the acquisition of imaging data under difficult diagnostic conditions.

    View details for PubMedID 7888437

  • [Candida glabrata pneumonia in a non-immunosuppressed patient: diagnostic imaging with digital luminescence radiography and CT]. Aktuelle Radiologie Bankier, A., Fleischmann, D., WIESMAYR, M., Laczika, K., Hübsch, P. 1994; 4 (4): 192-194

    Abstract

    Pneumonias caused by Candida glabrata are extremely rare and occur almost exclusively in immunocompromised patients. We report an atypical case of Candida glabrata pneumonia in a non-immunocompromised patient and describe the imaging findings on digital radiography and computed tomography.

    View details for PubMedID 7918708

  • [Percutaneous drainage of intra-abdominal abscesses in Crohn disease]. Aktuelle Radiologie WIESMAYR, M., Bankier, A., Fleischmann, D., Karnel, F. 1994; 4 (4): 184-187

    Abstract

    The majority of abcesses associated with Crohn's disease require surgical treatment. Since the postoperative rate of complications is high, particular care is needed in the choice of surgical therapy for patients with Crohn's disease. The interventional radiological method of percutaneous abcess drainage provides the surgeon with an alternative technique suitable both for the curative treatment of simple abcesses and for the palliation of complicated abcesses prior to elective surgical treatment. We have retrospectively analysed the drainage protocols, operation reports, and case histories of 7 patients with intra-abdominal abcesses in Crohn's disease. The results of our study emphasise the excellent clinical value of PAD in the treatment of abcesses associated with Crohn's disease.

    View details for PubMedID 7522578

  • [Bronchiolitis obliterans accompanied by organizing pneumonia: radiologic diagnosis in a case of a 22-year-old female]. Aktuelle Radiologie Bankier, A., Fleischmann, D., Baldt, M., Hübsch, P. 1994; 4 (1): 39-40

    Abstract

    Case report of a 22-year old patient with most severe idiopathic bronchiolitis obliterans and organising pneumonia. We discuss the diagnostic algorithm and emphasise the role of CT.

    View details for PubMedID 8136390

  • RAPID SCREENING FOR BACTERIURIA IN PREGNANCY INFECTION GRANINGER, W., Fleischmann, D., Schneeweiss, B., Aram, L., Stockenhuber, F. 1992; 20 (1): 9-11

    Abstract

    We evaluated a bioluminescence assay as a screening test for the detection of bacteriuria in pregnancy. A total of 1,000 urine specimens from a randomly selected group of pregnant women undergoing prenatal surveillance was investigated. Sequential dilution of urine specimens on CLED agar plates served as a reference method. Set against the reference group, bioluminescence screening scored a 93% sensitivity, a 78% specificity and a 99% predictive accuracy for negative results. All urine specimens were also analysed chemically for the presence of nitrite and leucocyte esterase by dip sticks. Dip sticks proved to be insufficient because of poor sensitivities of 54% and 59%, respectively. The bioluminescence assay is an effective, time- as well as labor-saving but questionably cost-effective method for the detection of bacteriuria in pregnancy.

    View details for Web of Science ID A1992HF59700002

    View details for PubMedID 1563815

  • In vitro uptake 153gadolinium and gadolinium complexes by hyaline articular cartilage. European journal of radiology Engel, A., Hamilton, G., Hajek, P., Fleischmann, D. 1990; 11 (2): 104-106

    Abstract

    This in vitro study evaluated whether Gadolinium (Gd) penetrates into hyaline cartilage and would be incorporated into vital chondrocytes. Hyaline joint cartilage of rabbits was exposed to radioactive 153GdCl3 and to a radioactive 153Gd-DTPA-BSA-complex (DTPA, diethylene-triaminepentaacetic acid; BSA, bovine serum albumine). In addition an exchange experiment with radioactive 153GdCl3 versus Gd-DTPA-di-N-methylglucamine (Magnevist) was performed. Incorporation of 153GdCl3 into neuroblastoma cells, connective tissue cells and chondrocytes was tested. The results showed that the depth and extent of incorporation of Gd depends on the molecular mass and time of exposure. 153Gd-DTPA-BSA complexes exhibited an incorporation rate of maximal 11% +/- 2.8% up to the middle third of the cartilage within 24 h with almost no incorporation (2 +/- 1.9%) for the deep layer. The exchange experiment revealed no uptake of Gd for the deep layer. The maximal incorporation rate of 153GdCl3 into vital chondrocytes was 6.3%. These data indicate that under the condition of MR-arthrography, Gd-DTPA-di-N-methylglucamine will not be absorbed into the deep layers of hyaline cartilage and will not be incorporated into vital chondrocytes.

    View details for PubMedID 1701389

Conference Proceedings


  • Computed tomographic angiography: Historical perspective and new state-of-the-art using multi detector-row helical computed tomography Rubin, G. D., Shiau, M. C., Schmidt, A. J., Fleischmann, D., Logan, L., Leung, A. N., Jeffrey, R. B., Napel, S. LIPPINCOTT WILLIAMS & WILKINS. 1999: S83-S90

    Abstract

    Since its clinical introduction in 1991, volumetric computed tomography scanning using spiral or helical scanners has resulted in a revolution for diagnostic imaging. In addition to new applications for computed tomography, such as computed tomographic angiography and the assessment of patients with renal colic, many routine applications such as the detection of lung and liver lesions have substantially improved. Helical computed tomographic technology has improved over the past eight years with faster gantry rotation, more powerful X-ray tubes, and improved interpolation algorithms, but the greatest advance has been the recent introduction of multi detector-row computed tomography scanners. These scanners provide similar scan quality at a speed gain of 3-6 times greater than single detector-row computed tomography scanners. This has a profound impact on the performance of computed tomography angiography, resulting in greater anatomic coverage, lower iodinated contrast doses, and higher spatial resolution scans than single detector-row systems.

    View details for Web of Science ID 000084391500012

    View details for PubMedID 10608402

  • AUTOMATIC PATIENT-INSTRUCTION DEVICES IN THIN-SECTION CT OF THE THORAX - IMPACT ON IMAGE QUALITY Bankier, A. A., Fleischmann, D., KANTENDORFER, K., WIESMAYR, M. N., Kontrus, M., Hubsch, P., Herold, C. J. RADIOLOGICAL SOC NORTH AMERICA. 1995: 841-844

    Abstract

    To determine what influence automatic patient-instruction (API) devices have on image quality of chest computed tomographic (CT) scans and whether the qualitative outcome justifies their routine use.Thin-collimation CT scans of two age- and sex-matched groups of 64 patients each were evaluated prospectively for the presence of breathing artifacts and for concomitant deterioration of image quality. Breathing commands in group 1 were given with the API device and in group 2 with technologist-performed patient instruction. Cardiac motion artifacts were not evaluated. The frequency of scans repeated owing to breathing artifact was determined.Image quality was worse in group 1 compared with that of group 2. The percentage of scans repeated was higher with API (38%) than without API (16%).API devices cannot be recommended for thin-section CT of the thorax. The large number of scans that must be repeated leads to a considerable increase in patient irradiation, scanning time, and cost.

    View details for Web of Science ID A1995RQ24300042

    View details for PubMedID 7644653

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