Bio

Clinical Focus


  • Diagnostic Radiology
  • Radiology
  • Cancer

Academic Appointments


Honors & Awards


  • RSNA Roentgen Resident/Fellow Research Award, RSNA (2007)
  • Chief Resident, Dept. of Radiology, Stanford University (2004-2005)
  • Molecular Biology for Imagers course scholarship, AUR (2005)
  • RSNA/AUR/ARRS Introduction to Research Program Scholarship, RSNA/AUR/ARRS (2003)
  • Stanford University Medical Center Dept. of Surgery 90th Percentile Award, Stanford University (2002)
  • Norman Blank Award for Excellence in Radiology, Stanford University (2001)
  • Featured Abstract, SIR Annual Meeting (2001)
  • Magna Cum Laude, Harvard University (1996)

Professional Education


  • Fellowship:Stanford University Hospital - Dept of Radiology (2008) CA
  • Residency:Stanford University - Dept of Radiology (2006) CA
  • Board Certification: Vascular and Interventional Radiology, American Board of Radiology
  • Board Certification: Vascular and Interventional Radiology, American Board of Radiology (2010)
  • BA, Harvard College, Biochemical Sciences (1996)
  • Medical Education:Stanford University School of Medicine (2001) CA
  • Internship:Stanford Hospital and Clinics - Dept of Surgery (2002) CA
  • Board Certification: Diagnostic Radiology, American Board of Radiology (2006)
  • Subspecialty Certificate, American Board of Radiology, Interventional Radiology (2010)

Research & Scholarship

Current Research and Scholarly Interests


Interventional oncology, pancreatic interventions, image-guided gene therapy.

Clinical Trials


  • Acute Venous Thrombosis: Thrombus Removal With Adjunctive Catheter-Directed Thrombolysis Recruiting

    The purpose of this study is to determine if the use of adjunctive Pharmacomechanical Catheter Directed Thrombolysis, which includes the intrathrombus administration of rt-PA--Activase (Alteplase),can prevent the post-thrombotic syndrome(PTS)in patients with symptomatic proximal deep vein thrombosis(DVT)as compared with optimal standard DVT therapy alone.

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  • ExAblate (Magnetic Resonance-guided Focused Ultrasound Surgery) Treatment of Metastatic Bone Tumors for the Palliation of Pain Not Recruiting

    A Pivotal Study to Evaluate the Effectiveness and Safety of ExAblate Treatment of Metastatic Bone and Multiple Myeloma Tumors for the Palliation of Pain in Patients Who are not Candidates for Radiation Therapy

    Stanford is currently not accepting patients for this trial. For more information, please contact Kamil Unver, (650) 725 - 9810.

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  • Pulmonary Embolism Response to Fragmentation, Embolectomy, & Catheter Thrombolysis: PERFECT Recruiting

    A prospective observational study to evaluate the safety and effectiveness data of catheter-directed therapy (CDT) including percutaneous mechanical thrombectomy (PMT) for treatment of acute pulmonary embolism (PE)

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  • A Phase 2b Study of Modified Vaccinia Virus to Treat Patients Advanced Liver Cancer Who Failed Sorafenib Not Recruiting

    This study is to determine whether JX-594 (Pexa-Vec) plus best supportive care is more effective in improving survival than best supportive care in patients with advanced Hepatocellular Carcinoma (HCC) who have failed sorafenib.

    Stanford is currently not accepting patients for this trial. For more information, please contact Fizaa Ahmed, (650) 725 - 6409.

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  • HepaSphere/Quadrasphere Microspheres for Delivery of Doxorubicin for the Treatment of Hepatocellular Cancer Recruiting

    The purpose of this study is to evaluate overall survival in patients treated with HepaSphere/QuadraSphere compared to conventional transarterial chemoembolization with particle PVA.

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  • FILTER - Filter Initial & Long Term Evaluation After Placement and Retrieval (Including Laser-Assisted Retrieval) Registry Recruiting

    A data registry for all patients who undergo IVC (Inferior Vena Cava) filter placement or retrieval at Stanford. Potential enrollees will already be undergoing the procedure. If patients are willing, they will be prospectively enrolled prior to the procedure. As part of the study, chart and clinical data reviews will be used to track patient progress and response to the treatment.

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  • The GORE Viabahn Endoprosthesis for the Treatment of Venous Occlusions and Stenoses Recruiting

    To study the safety and efficacy of drug coated stents for the treatment of venous occlusions and stenoses in the lower extremity. The use of the device for the treatment of peripheral arterial disease is approved by the FDA, however, the use of the device in venous occlusions and stenoses, although performed by some practitioners, has not yet been studied in detail.

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  • Impact of C-arm CT in Decreased Renal Function Undergoing TACE for Tx of Hepato-Cellular Carcinoma Not Recruiting

    Impact on contrast dose or total volume of contrast required to effectively treat the targeted tumor.

    Stanford is currently not accepting patients for this trial. For more information, please contact Kamil Unver, (650) 725 - 9810.

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  • Impact of C-arm CT in Patients With HCC Undergoing TACE: Optimal Imaging Guidance Not Recruiting

    Patients will be enrolled based on presence of HCC and eligibility for TACE. They will be randomized to one of two arms for imaging navigation to the optimal catheter location for chemotherapy injection to treat the first (possibly sole) tumor target. The two arms will be: TACE using F and DSA only, or TACE using F, DSA, and CACT. Navigation to subsequent treatment targets in all patients will be done with fluoroscopy, CACT, and DSA, as is standard of care at Stanford University Medical Center, and is not part of the study. Vascular complexity, which affects navigation difficulty and thus the need for imaging, will be assessed separately for use in data analysis by two radiologists on a four-point scale.

    Stanford is currently not accepting patients for this trial. For more information, please contact Kamil Unver, (650) 725 - 9810.

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Teaching

2013-14 Courses


Publications

Journal Articles


  • Yttrium-90 Radioembolization of Renal Cell Carcinoma Metastatic to the Liver JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Abdelmaksoud, M. H., Louie, J. D., Hwang, G. L., Kothary, N., Minor, D. R., Sze, D. Y. 2012; 23 (3): 323-330

    Abstract

    To investigate the safety and efficacy of yttrium-90 ((90)Y) hepatic radioembolization treatment of patients with liver-dominant metastatic renal cell carcinoma (RCC) refractory to immunotherapy and targeted therapies.Between March 2006 and December 2010, six patients with metastatic RCC underwent eight radioembolization treatments with (90)Y-labeled resin microspheres for unresectable liver-dominant metastases. All six patients had previous hepatic tumor progression despite targeted therapies or immunotherapies. All had bilobar disease and required whole-liver treatment. Clinical and biochemical toxicities were recorded, and tumor response was assessed every 2-3 months after treatment by cross-sectional imaging.The median dose delivered was 1.89 Gbq (range 0.41-2.03 Gbq). Grade 1 and 2 toxicities were noted in all patients, primarily fatigue. Follow-up imaging was available for five patients. In follow-up periods from 2-64 months (mean 25 months), three patients showed complete responses, and 1 patient showed a partial response by standard imaging criteria, and these patients are alive at 64 months, 55 months, 17 months, and 7 months after treatment. Two patients with rapid progression of disease died within 2 months of treatment, although hepatic malignancy or failure was not the cause of death in either patient.(90)Y radioembolization is a promising option for liver-dominant metastatic RCC with potential for providing long-term survival in patients refractory to or intolerant of targeted therapies.

    View details for DOI 10.1016/j.jvir.2011.11.007

    View details for Web of Science ID 000301328100007

    View details for PubMedID 22277275

  • Transarterial Chemoembolization for Hepatocellular Carcinomas in Watershed Segments: Utility of C-Arm Computed Tomography for Treatment Planning JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Abdelmaksoud, M. H., Louie, J. D., Hwang, G. L., Sze, D. Y., Hofmann, L. V., Kothary, N. 2012; 23 (2): 281-283

    View details for DOI 10.1016/j.jvir.2011.11.008

    View details for Web of Science ID 000299656600021

    View details for PubMedID 22264556

  • Percutaneous Cholecystostomy for Acute Cholecystitis: Ten-Year Experience JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Joseph, T., Unver, K., Hwang, G. L., Rosenberg, J., Sze, D. Y., Hashimi, S., Kothary, N., Louie, J. D., Kuo, W. T., Hofmann, L. V., Hovsepian, D. M. 2012; 23 (1): 83-88

    Abstract

    To review the clinical course of patients with acute cholecystitis treated by percutaneous cholecystostomy, and to identify risk factors retrospectively that predict outcome.A total of 106 patients diagnosed with acute cholecystitis were treated by percutaneous cholecystostomy during a 10-year period. Seventy-one (67%) presented to the emergency department (ED) specifically for acute cholecystitis, and 35 (23%) were inpatients previously admitted for other conditions. Outcomes of the two groups were compared with respect to severity of illness, leukocytosis, bile culture, liver function tests, imaging features, time intervals from onset of symptoms to medical and percutaneous intervention, and whether surgical cholecystectomy was later performed.Overall, 72 patients (68%) showed an improvement clinically, whereas 34 (32%) showed no improvement or a clinically worsened condition after cholecystostomy. Patients who presented to the ED primarily with acute cholecystitis fared better (84% of patients showed improvement) than inpatients (34% showed improvement; P < .0001). Gallstones were identified in 54% of patients who presented to the ED, whereas acalculous cholecystitis was more commonly diagnosed in inpatients (54%). Patients with sepsis had worse outcomes overall (P < .0001). Bacterial bile cultures were analyzed in 95% of patients and showed positive results in 52%, with no overall effect on outcome. There was no correlation between the time of onset of symptoms until antibiotic therapy or cholecystostomy in either group. Long-term outcomes for both groups were better for those who later underwent cholecystectomy (P < .0001).Outcomes after percutaneous cholecystostomy for acute cholecystitis are better when the disease is primary and not precipitated by concurrent illness.

    View details for DOI 10.1016/j.jvir.2011.09.030

    View details for Web of Science ID 000299151400015

    View details for PubMedID 22133709

  • Imaging Guidance with C-arm CT: Prospective Evaluation of Its Impact on Patient Radiation Exposure during Transhepatic Arterial Chemoembolization JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Kothary, N., Abdelmaksoud, M. H., Tognolini, A., Fahrig, R., Rosenberg, J., Hovsepian, D. M., Ganguly, A., Louie, J. D., Kuo, W. T., Hwang, G. L., Holzer, A., Sze, D. Y., Hofmann, L. V. 2011; 22 (11): 1535-1544

    Abstract

    To prospectively evaluate the impact of C-arm CT on radiation exposure to hepatocellular carcinoma (HCC) patients treated by chemoembolization.Patients with HCC (N = 87) underwent digital subtraction angiography (DSA; control group) or combined C-arm CT/DSA (test group) for chemoembolization. Dose-area product (DAP) and cumulative dose (CD) were measured for guidance and treatment verification. Contrast agent volume and C-arm CT utility were also measured.The marginal DAP increase in the test group was offset by a substantial (50%) decrease in CD from DSA. Use of C-arm CT allowed reduction of DAP and CD from DSA imaging (P = .007 and P = .017). Experienced operators were more efficient in substituting C-arm CT for DSA, resulting in a negligible increase (7.5%) in total DAP for guidance, compared with an increase of 34% for all operators (P = .03). For treatment verification, DAP from C-arm CT exceeded that from DSA, approaching that of conventional CT. The test group used less contrast medium (P = .001), and C-arm CT provided critical or supplemental information in 20% and 17% of patients, respectively.Routine use of C-arm CT can increase stochastic risk (DAP) but decrease deterministic risk (CD) from DSA. However, the increase in DAP is operator-dependent, thus, with experience, it can be reduced to under 10%. C-arm CT provides information not provided by DSA in 33% of patients, while decreasing the use of iodinated contrast medium. As with all radiation-emitting modalities, C-arm CT should be used judiciously.

    View details for DOI 10.1016/j.jvir.2011.07.008

    View details for Web of Science ID 000296661800008

    View details for PubMedID 21875814

  • In Vitro Design and Characterization of the Nonviral Gene Delivery Vector lopamidol, Protamine, Ethiodized Oil Reagent JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Higgins, L. J., Hwang, G. L., Rosenberg, J., Katzenberg, R. H., Kothary, N., Sze, D. Y., Hofmann, L. V. 2011; 22 (10): 1457-1463

    Abstract

    To demonstrate cellular selectivity toward hepatoma cells and compare the efficiency of gene delivery of a novel nonviral vector of iopamidol, protamine, and ethiodized oil reagents (VIPER).Rat hepatocellular carcinoma (HCC) cells were transfected in triplicate under varying conditions by using firefly luciferase as a reporter gene. Conditions included variations of a protamine:DNA (P:D) complex (20:1, 50:1, 100:1, 200:1 mass ratios), iopamidol (0%, 10%, 33%), and ethiodized oil (0%, 1%, 2%, 4%, 8%, and 16%). The conditions affording efficient gene transfer and ease of translation to in vivo studies were selected for cell line comparison (HCC cells vs hepatocytes). Adenoviral transduction was compared with nonviral vector transfection.At low concentrations, ethiodized oil increased transfection efficiency regardless of P:D mass ratio. However, high concentrations resulted in significant attenuation. Unexpectedly, the addition of iopamidol to P:D complexes markedly improved transfection efficiency. When using an optimal P:D, iopamidol, and ethiodized oil solution, DNA transfection of normal liver and tumor cells showed significant selectivity for tumor cells. In the context of hepatoma cells, transfection efficiency with the nonviral vector was better than 10(4) pfu adenovirus.The development and characterization of the VIPER system provides a possible alternative to viral gene therapy of HCC.

    View details for DOI 10.1016/j.jvir.2011.06.025

    View details for Web of Science ID 000295708400018

    View details for PubMedID 21856173

  • Embolization of Parasitized Extrahepatic Arteries to Reestablish Intrahepatic Arterial Supply to Tumors before Yttrium-90 Radioembolization JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Abdelmaksoud, M. H., Louie, J. D., Kothary, N., Hwang, G. L., Kuo, W. T., Hofmann, L. V., Hovsepian, D. M., Sze, D. Y. 2011; 22 (10): 1355-1362

    Abstract

    To perform embolization of parasitized extrahepatic arteries (EHAs) before radioembolization to reestablish intrahepatic arterial supply to large, peripheral tumors, and to evaluate the technical and clinical outcomes of this intervention.Among 201 patients retrospectively analyzed, embolization of 73 parasitized EHAs in 35 patients was performed. Most embolization procedures were performed during preparatory angiography using large particles and coils. Digital subtraction angiography (DSA), C-arm computed tomography (CT), and technetium-99m macroaggregated albumin ((99m)TcMAA) scintigraphy were used to evaluate the immediate perfusion via intrahepatic collateral channels of target tumor areas previously supplied by parasitized EHAs. Follow-up imaging of differential regional tumor response was used to evaluate microsphere distribution and clinical outcome.After embolization, reestablishment of intrahepatic arterial supply was confirmed by both DSA and C-arm CT in 94% of territories and by scintigraphy in 96%. In 32% of patients, the differential response of treatment could not be evaluated because of uniform disease progression. However, symmetric regional tumor response in 94% of evaluable patients indicated successful delivery of microspheres to the territories previously supplied by parasitized EHAs.Reestablishment of intrahepatic arterial inflow to hepatic tumors by embolization of parasitized EHAs is safe and effective and results in successful delivery of yttrium-90 microspheres to tumors previously perfused by parasitized EHAs.

    View details for DOI 10.1016/j.jvir.2011.06.007

    View details for Web of Science ID 000295708400002

    View details for PubMedID 21961979

  • Consolidation of Hepatic Arterial Inflow by Embolization of Variant Hepatic Arteries in Preparation for Yttrium-90 Radioembolization JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Abdelmaksoud, M. H., Louie, J. D., Kothary, N., Hwang, G. L., Kuo, W. T., Hofmann, L. V., Hovsepian, D. M., Sze, D. Y. 2011; 22 (10): 1364-1372

    Abstract

    Before yttrium-90 ((90)Y) radioembolization administration, the authors consolidated arterial inflow by embolizing variant hepatic arteries (HAs) to make microsphere delivery simpler and safer. The present study reviews the technical and clinical success of these consolidation procedures.Preparatory and treatment angiograms were retrospectively analyzed for 201 patients. Variant HAs were coil-embolized during preparatory angiography to simplify arterial anatomy. Collateral arterial perfusion of territories previously supplied by variant HAs was evaluated by digital subtraction angiography (DSA), C-arm computed tomography (CT), and technetium-99m ((99m)Tc)-macroaggregated albumin (MAA) scintigraphy, and by follow-up evaluation of regional tumor response.A total of 47 variant HAs were embolized in 43 patients. After embolization of variant HAs, cross-perfusion into the embolized territory was depicted by DSA and by C-arm CT in 100% of patients and by (99m)Tc-MAA scintigraphy in 92.7%. Uniform progressive disease prevented evaluation in 33% of patients, but regional tumor response in patients who responded supported successful delivery of microspheres to the embolized territories in 95.5% of evaluable patients.Embolization of variant HAs for consolidation of hepatic supply in preparation for (90)Y radioembolization promotes treatment of affected territories via intrahepatic collateral channels.

    View details for DOI 10.1016/j.jvir.2011.06.014

    View details for Web of Science ID 000295708400004

    View details for PubMedID 21961981

  • Photothermal Ablation with the Excimer Laser Sheath Technique for Embedded Inferior Vena Cava Filter Removal: Initial Results from a Prospective Study JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Kuo, W. T., Odegaard, J. I., Louie, J. D., Sze, D. Y., Unver, K., Kothary, N., Rosenberg, J. K., Hovsepian, D. M., Hwang, G. L., Hofmann, L. V. 2011; 22 (6): 813-823

    Abstract

    To evaluate the safety and effectiveness of the excimer laser sheath technique for removing embedded inferior vena cava (IVC) filters.Over 12 months, 25 consecutive patients undergoing attempted IVC filter retrieval with a laser-assisted sheath technique were prospectively enrolled into an institutional review board-approved study registry. There were 10 men and 15 women (mean age 50 years, range 20-76 years); 18 (72%) of 25 patients were referred from an outside hospital. Indications for retrieval included symptomatic filter-related acute caval thrombosis (with or without acute pulmonary embolism), chronic IVC occlusion, and bowel penetration. Retrieval was also performed to remove risks from prolonged implantation and potentially to eliminate need for lifelong anticoagulation. After failure of standard methods, controlled photothermal ablation of filter-adherent tissue with a Spectranetics laser sheath and CVX-300 laser system was performed. All patients were evaluated with cavography, and specimens were sent for histologic analysis.Laser-assisted retrieval was successful in 24 (96%) of 25 patients as follows: 11 Günther Tulip (mean 375 days, range 127-882 days), 4 Celect (mean 387 days, range 332-440 days), 2 Option (mean 215 days, range 100-330 days), 4 OPTEASE (mean 387 days, range 71-749 days; 1 failed 188 days), 2 TRAPEASE (mean 871 days, range 187-1,555 days), and 2 Greenfield (mean 12.8 years, range 7.2-18.3 years). There was one (4%) major complication (acute thrombus, treated with thrombolysis), three (12%) minor complications (small extravasation, self-limited), and one adverse event (coagulopathic retroperitoneal hemorrhage) at follow-up (mean 126 days, range 13-302 days). Photothermal ablation of filter-adherent tissue was histologically confirmed in 23 (92%) of 25 patients.The laser-assisted sheath technique appears to be a safe and effective tool for retrieving embedded IVC filters, including permanent types, with implantation ranging from months to > 18 years.

    View details for DOI 10.1016/j.jvir.2011.01.459

    View details for Web of Science ID 000291414500011

    View details for PubMedID 21530309

  • Intrahepatic Collateral Supply to the Previously Embolized Right Gastric Artery: A Potential Pitfall for Nontarget Radioembolization JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Meer, A. B., Louie, J. D., Abdelmaksoud, M. H., Kothary, N., Hovsepian, D. M., Hofmann, L. V., Kuo, W. T., Hwang, G. L., Sze, D. Y. 2011; 22 (4): 575-577

    View details for DOI 10.1016/j.jvir.2010.12.031

    View details for Web of Science ID 000289340100024

    View details for PubMedID 21463762

  • Common Iliac Vein Stenosis and Risk of Symptomatic Pulmonary Embolism: An Inverse Correlation JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Chan, K. T., Popat, R. A., Sze, D. Y., Kuo, W. T., Kothary, N., Louie, J. D., Hovsepian, D. M., Hwang, G. L., Hofmann, L. V. 2011; 22 (2): 133-141

    Abstract

    To test the hypothesis that a common iliac vein (CIV) stenosis may impair embolization of a large deep venous thrombosis (DVT) to the lungs, decreasing the incidence of a symptomatic pulmonary embolism (PE).Between January 2002 and August 2007, 75 patients diagnosed with unilateral DVT were included in a single-institution case-control study. Minimum CIV diameters were measured 1 cm below the inferior vena cava (IVC) bifurcation on computed tomography (CT) images. A significant stenosis in the CIV ipsilateral to the DVT was defined as having either a diameter 4 mm or less or a greater than 70% reduction in lumen diameter. A symptomatic PE was defined as having symptoms and imaging findings consistent with a PE. The odds of symptomatic PE versus CIV stenosis were assessed using logistic regression models. The associations between thrombus location, stenosis, and symptomatic PE were assessed using a stratified analysis.Of 75 subjects, 49 (65%) presented with symptomatic PE. There were 17 (23%) subjects with a venous lumen 4 mm or less and 12 (16%) subjects with a greater than 70% stenosis. CIV stenosis of 4 mm or less resulted in a decreased odds of a symptomatic PE compared with a lumen greater than 4 mm (odds ratio [OR] 0.17, P = .011), whereas a greater than 70% stenosis increased the odds of DVT involving the CIV (OR 7.1, P = .047).Among patients with unilateral DVT, those with an ipsilateral CIV lumen of 4 mm or less have an 83% lower risk of developing symptomatic PE compared with patients with a CIV lumen greater than 4 mm.

    View details for DOI 10.1016/j.jvir.2010.10.009

    View details for Web of Science ID 000287166600004

    View details for PubMedID 21276911

  • Renewing Focus on Resident Education: Increased Responsibility and Ownership in Interventional Radiology Rotations Improves the Educational Experience JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Kothary, N., Ghatan, C. E., Hwang, G. L., Kuo, W. T., Louie, J. D., Sze, D. Y., Hovsepian, D. M., Desser, T. S., Hofmann, L. V. 2010; 21 (11): 1697-1702

    Abstract

    To enhance the educational experience among residents rotating through interventional radiology (IR) by encouraging ownership and responsibility.In May 2006, the authors implemented changes in resident education in IR that included increased clinical responsibilities, structured didactics, and greater hands-on experience, including call. Residents were assigned as first assistants, ownership of cases was encouraged, and assignment to a week on the consult service was instituted to help residents better understand all aspects of IR practice. Additional faculty recruitment and program expansion ensured the same high level of training for the fellowship program. Evaluations were reviewed every year (July 1, 2007-June 30, 2009) for hands-on training, daily teaching, didactic conferences, and overall effectiveness of the clinical service. A graduated scale of 1-5 was used.In 2009, 3 years after the curricular changes were made, the quality of hands-on training, daily case reviews and consults, didactics, and overall education had markedly improved with 89%, 71%, 65%, and 82% of the residents rating these respective aspects of the training as "above expectations" (4 on a scale of 5) or "superior" (5 on a scale of 5) compared with 77%, 23%, 20%, and 60% in 2005-2006. Three years after the changes, the impact of these changes on recruitment patterns also showed improvement, with 28.6% of the class of 2010 pursuing a fellowship in IR.Increasing resident ownership, responsibility, and hands-on experience improves resident education in IR, which, in turn, promotes interest in the field.

    View details for DOI 10.1016/j.jvir.2010.07.009

    View details for Web of Science ID 000284244200009

    View details for PubMedID 20884234

  • Development of New Hepaticoenteric Collateral Pathways after Hepatic Arterial Skeletonization in Preparation for Yttrium-90 Radioembolization JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Abdelmaksoud, M. H., Hwang, G. L., Louie, J. D., Kothary, N., Hofmann, L. V., Kuo, W. T., Hovsepian, D. M., Sze, D. Y. 2010; 21 (9): 1385-1395

    Abstract

    Development of new hepaticoenteric anastomotic vessels may occur after endovascular skeletonization of the hepatic artery. Left untreated, they can serve as pathways for nontarget radioembolization. The authors reviewed the incidence, anatomy, management, and significance of collateral vessel formation in patients undergoing radioembolization.One hundred thirty-eight treatments performed on 122 patients were reviewed. Each patient underwent a preparatory digital subtraction angiogram (DSA) and embolization of all hepaticoenteric vessels in preparation for yttrium-90 ((90)Y) administration. Successful skeletonization was verified by C-arm computed tomography (CACT) and technetium-99m macroaggregated albumin ((99m)TcMAA) scintigraphy. During the subsequent treatment session, DSA and CACT were repeated before administration of (90)Y, and the detection of extrahepatic perfusion prompted additional embolization.Forty-two patients (34.4%) undergoing 43 treatments (31.2%) required adjunctive embolization of hepaticoenteric vessels immediately before (90)Y administration. Previous scintigraphy findings showed extrahepatic perfusion in only three cases (7.1%). Vessels were identified by DSA in 54.1%, by CACT in 4.9%, or required both in 41.0%. The time interval between angiograms did not correlate with risk of requiring reembolization (P = .297). A total of 19.7% of vessels were new collateral vessels not visible during the initial angiography. Despite reembolization, three patients (7.1%) had gastric or duodenal ulceration, compared with 1.3% who never had visible collateral vessels, all of whom underwent whole-liver treatment with resin microspheres (P = .038).Development of collateral hepaticoenteric anastomoses occurs after endovascular skeletonization of the hepatic artery. Identified vessels may be managed by adjunctive embolization, but patients appear to remain at increased risk for gastrointestinal complications.

    View details for DOI 10.1016/j.jvir.2010.04.030

    View details for Web of Science ID 000281620600012

    View details for PubMedID 20688531

  • Computed Tomography-Guided Percutaneous Needle Biopsy of Indeterminate Pulmonary Pathology: Efficacy of Obtaining a Diagnostic Sample in Immunocompetent and Immunocompromised Patients CLINICAL LUNG CANCER Kothary, N., Bartos, J. A., Hwang, G. L., Dua, R., Kuo, W. T., Hofmann, L. V. 2010; 11 (4): 251-256

    Abstract

    We aimed to evaluate the efficacy of computed tomography (CT)-guided percutaneous lung biopsy of pulmonary nodules with indeterminate radiologic characteristics in patients at risk for malignant and nonmalignant processes such as infection or inflammation.From January 2003 to September 2008, 262 patients (mean age, 59 years; range, 18-92 years) with pulmonary nodules or a mass of uncertain etiology and with indeterminate radiologic characteristics underwent CT-guided percutaneous lung biopsy. Patients with discordant clinical history and imaging findings or immunocompromised patients at risk for both etiologies were included. Specimens were submitted for both cytology and microbiology.Of the entire cohort, 166 patients (63.4%) had a nonmalignant process, and 96 patients (36.6%) had a malignancy. CT-guided percutaneous lung biopsy established a diagnosis in 166 patients (63.4%). Of the 166 patients with a nonmalignant etiology and 96 patients with malignancy, it provided a definitive diagnosis in 91 patients (54.8%) and 75 patients (78.1%), respectively, a difference that was statistically significant (P = .0001). Overall diagnostic efficacy between immunocompetent and immunocompromised patients was comparable (P = .2); however, detection of infection or inflammation in individual groups was lower compared with detection of malignancy (P = .002 and P = .06, respectively).CT-guided percutaneous lung biopsy in patients who are clinically at risk for both nonmalignant and malignant processes continues to be a challenge. Although CT-guided percutaneous biopsy can establish an accurate diagnosis in a large majority of patients with malignancy, it is significantly less sensitive for infectious or inflammatory processes.

    View details for DOI 10.3816/CLC.2010.n.032

    View details for Web of Science ID 000279496400006

    View details for PubMedID 20630827

  • Utility of C-arm CT in Patients with Hepatocellular Carcinoma undergoing Transhepatic Arterial Chemoembolization JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Tognolini, A., Louie, J. D., Hwang, G. L., Hofmann, L. V., Sze, D. Y., Kothary, N. 2010; 21 (3): 339-347

    Abstract

    To evaluate the utility of C-arm computed tomography (CT) on treatment algorithms in patients undergoing transhepatic arterial chemoembolization for hepatocellular carcinoma (HCC).From March 2008 to July 2008, 84 consecutive patients with HCC underwent 100 consecutive transhepatic arterial chemoembolizations with iodized oil. Unenhanced and iodinated contrast medium-enhanced C-arm CT with planar and three-dimensional imaging were performed in addition to conventional digital subtraction angiography (DSA) in all patients. The effect on diagnosis and treatment was determined by testing the hypotheses that C-arm CT, in comparison to DSA, provides (a) improved lesion detection, (b) expedient identification and mapping of arterial supply to a tumor, (c) improved characterization of a lesion to allow confident differentiation of HCC from pseudolesions such as arterioportal shunts, and (d) an improved evaluation of treatment completeness. The effect of C-arm CT was analyzed on the basis of information provided with C-arm CT that was not provided or readily apparent at DSA.C-arm CT was technically successful in 93 of the 100 procedures (93%). C-arm CT provided information not apparent or discernible at DSA in 30 of the 84 patients (36%) and resulted in a change in diagnosis, treatment planning, or treatment delivery in 24 (28%). The additional information included, amongst others, visualization of additional or angiographically occult tumors in 13 of the 84 patients (15%) and identification of incomplete treatment in six (7.1%).C-arm CT is a useful collaborative tool in patients undergoing transhepatic arterial chemoembolization and can affect patient care in more than one-fourth of patients.

    View details for DOI 10.1016/j.jvir.2009.11.007

    View details for Web of Science ID 000277367700005

    View details for PubMedID 20133156

  • High-risk Retrieval of Adherent and Chronically Implanted IVC Filters: Techniques for Removal and Management of Thrombotic Complications JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Kuo, W. T., Tong, R. T., Hwang, G. L., Louie, J. D., Lebowitz, E. A., Sze, D. Y., Hofmann, L. V. 2009; 20 (12): 1548-1556

    Abstract

    To evaluate the safety and efficacy of aggressive techniques for retrieving adherent and chronically implanted inferior vena cava (IVC) filters.A single-center retrospective review was performed on all patients who underwent attempted filter retrieval from October 2007 through October 2008. Patients were included in the study if they had an adherent filter, refractory to standard retrieval techniques, and underwent high-risk retrieval after procedural risks were deemed lower than risks of long-term filter implantation.Fourteen patients were diagnosed with an adherent filter, 13 (93%) of whom were candidates for high-risk retrieval. These patients included seven men and six women (mean age, 40 years; age range, 18-71 years). Nine of the 13 patients (69%) were referred from an outside hospital. Filter retrieval was performed for the following indications: to avoid the risk of long-term thrombotic complications in a young patient (n= 6), to treat symptomatic filter-related IVC stenosis (n= 5), to treat symptomatic filter penetration (n= 1), and to avoid the need for lifelong anticoagulation (n= 1). There were eight Günther-Tulip filters (mean dwell time, 356 days; range 53-1,181 days), two Optease filters (mean dwell time, 62 days; range, 52-72 days), one G2 filter (dwell time, 420 days), and two Recovery filters (mean dwell time, 1,630 days; range, 1,429-1,830 days). Three IVC occlusions necessitated recanalization to facilitate retrieval. High-risk retrieval with use of various techniques with aggressive force was successful in all 13 patients (100%). Partial caval thrombosis occurred in the first four patients (31%) but did not occur after procedural modifications were implemented. There were no complications at clinical follow-up (mean, 221 days; range, 84-452 days).Alternative techniques can be used to retrieve adherent IVC filters implanted for up to 3-5 years. Although caval thrombosis was an observed complication, protocol modifications appeared to reduce this risk.

    View details for DOI 10.1016/j.jvir.2009.08.024

    View details for Web of Science ID 000272636200005

    View details for PubMedID 19864160

  • Incorporating Cone-beam CT into the Treatment Planning for Yttrium-90 Radioembolization JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Louie, J. D., Kothary, N., Kuo, W. T., Hwang, G. L., Hofmann, L. V., Goris, M. L., Iagaru, A. H., Sze, D. Y. 2009; 20 (5): 606-613

    Abstract

    To prepare for yttrium-90 ((90)Y) microsphere radioembolization therapy, digital subtraction angiography (DSA) and technetium- 99m-labeled macroaggregated albumin ((99m)Tc MAA) scintigraphy are used for treatment planning and detection of potential nontarget embolization. The present study was performed to determine if cone-beam computed tomography (CBCT) affects treatment planning as an adjunct to these conventional imaging modalities.From March 2007 to August 2008, 42 consecutive patients (21 men, 21 women; mean age, 59 years; range, 21-75 y) who underwent radioembolization were evaluated by CBCT in addition to DSA and (99m)Tc MAA scintigraphy during treatment planning, and their records were retrospectively reviewed. The contrast-enhanced territories shown by CBCT with selective intraarterial contrast agent administration were used to predict intrahepatic and possible extrahepatic distribution of microspheres.In 22 of 42 cases (52%), extrahepatic enhancement or incomplete tumor perfusion seen on CBCT affected the treatment plan. In 14 patients (33%), the findings were evident exclusively on CBCT and not detected by DSA. When comparing CBCT versus (99m)Tc MAA scintigraphy, CBCT showed eight cases of extrahepatic enhancement (19%) that were not evident on (99m)Tc MAA imaging. CBCT findings directed the additional embolization of vessels or repositioning of the catheter for better contrast agent and microsphere distribution. One case of gastric ulcer from nontarget embolization caused by reader error was observed.CBCT can provide additional information about tumor and tissue perfusion not currently detectable by DSA or (99m)Tc MAA imaging, which should optimize (90)Y microsphere delivery and reduce nontarget embolization.

    View details for DOI 10.1016/j.jvir.2009.01.021

    View details for Web of Science ID 000265700900007

    View details for PubMedID 19345589

  • Bidirectionally Adjustable TIPS Reduction by Parallel Stent and Stent-Graft Deployment JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Sze, D. Y., Hwang, G. L., Kao, J. S., Frisoli, J. K., Kee, S. T., Razavi, M. K., Ahmed, A. 2008; 19 (11): 1653-1658

    Abstract

    Excessive shunting through transjugular intrahepatic portosystemic shunts (TIPS) can cause life-threatening hepatic encephalopathy and insufficiency. Intentional reduction of flow may be effective but difficult to control. The present report describes refinements of the parallel stent/stent-graft technique of flow reduction that is adjustable in either direction. Six patients underwent TIPS reduction with varying stent positioning and a variety of commercial products. Flow was adjusted by iterative balloon dilatation of the stent and stent-graft, resulting in a mean gradient increase of 8 mm Hg. All cases were technically successful, but 1-year survival was seen in only the patient who underwent liver transplantation.

    View details for DOI 10.1016/j.jvir.2008.08.011

    View details for Web of Science ID 000260694700018

    View details for PubMedID 18823797

  • Role of image-guided vascular intervention in therapeutic angiogenesis translational research. Expert review of cardiovascular therapy Hwang, G. L., Patel, T. H., Hofmann, L. V. 2007; 5 (5): 903-915

    Abstract

    Therapeutic angiogenesis, the process of growing collateral blood vessels to better perfuse ischemic tissue, has been hailed as an up-and-coming treatment for symptomatic lower-extremity peripheral arterial occlusive disease. A minimally invasive durable treatment would be welcome since current treatment options for this disease carry high risk, limited efficacy or limited durability. Unfortunately, as evidenced by disappointing results in multiple clinical trials, therapeutic angiogenesis has yet to deliver in humans the success it has seen in animal models. In this review, we discuss the challenges of translating therapeutic angiogenesis into effective clinical treatments for lower-extremity peripheral arterial occlusive disease and we highlight the role that experts in image-guided vascular interventions can play in advancing the field.

    View details for PubMedID 17867920

  • Recurrent lymphoma of the lung - Computed tomography appearance JOURNAL OF COMPUTER ASSISTED TOMOGRAPHY Hwang, G. L., Leung, A. N., Zinck, S. E., Berry, G. J. 2005; 29 (2): 228-230

    Abstract

    To describe the computed tomography findings of recurrent lymphoma involving the lung.Computed tomography scans of 15 patients with biopsy-proven recurrent lymphoma involving the lung were reviewed. Group mean age of enrolled patients was 38 years (range: 14-68 years). Pathologic specimens were obtained by thoracoscopic or open wedge biopsy (n = 8), transbronchial biopsy (n = 5), and fine needle aspiration (n = 2).Nodules, the most common manifestation, were present in all patients; nodules were greater than 10 in number in 12 (80%) of 15 cases and predominantly 6-10 mm in size in 8 cases (53%). Nodular distribution was bilateral and multilobar except in 2 patients, in whom a solitary pulmonary nodule was found. Lymphadenopathy was the second most common finding; it was seen in 13 (87%) of 15 cases and involved an average of 5 nodal stations.Recurrent lymphoma in the lung most commonly manifests as multiple pulmonary nodules that are typically bilateral and multilobar in distribution.

    View details for Web of Science ID 000228030400014

    View details for PubMedID 15772542

  • Abdominal myomectomy versus uterine fibroid embolization in the treatment of symptomatic uterine leiomyomas AMERICAN JOURNAL OF ROENTGENOLOGY Razavi, M. K., Hwang, G., Jahed, A., Modanloo, S., Chen, B. 2003; 180 (6): 1571-1575

    Abstract

    The purpose of this study was to compare treatment efficacy and complications of abdominal myomectomy with those of uterine fibroid embolization in women with symptomatic uterine fibroids.We analyzed the outcomes of 111 consecutive patients who underwent abdominal myomectomy (n = 44) or fibroid embolization (n = 67) over a 30-month period. The mean ages of the two groups were 37.7 years (range, 28-48 years) and 44.2 years (range, 31-56 years), respectively. A questionnaire and review of medical records assessed all procedure-related complications and changes in symptoms. Length of hospital stay, time until resumption of daily activities, and pain medication requirements after the procedure were also analyzed.Follow-up times for the myomectomy and embolization groups were 14.6 and 14.3 months, respectively. The respective observed success rates in abdominal myomectomy and uterine fibroid embolization patients were 64% versus 92% for menorrhagia (p < 0.05), 54% versus 74% for pain (not significant), and 91% versus 76% for mass effect (p < 0.05). The complication rates were 25% (abdominal myomectomy) and 11% (uterine fibroid embolization) (p < 0.05). The respective secondary end points for the two procedures were 2.9 versus 0 days mean hospital stay, 8.7 versus 5.1 days of narcotics use, and 36 versus 8 days until resumption of normal activities. These differences were all statistically significant.Uterine fibroid embolization is a less invasive and safer treatment option in women with symptomatic leiomyomas than myomectomy. Menorrhagia may be better controlled with embolization, and myomectomy may be a better option in patients with mass effect. Both procedures were equally effective in controlling pain.

    View details for Web of Science ID 000183149200013

    View details for PubMedID 12760922

  • Chronic expanding hematoma of the thorax AMERICAN JOURNAL OF ROENTGENOLOGY Hwang, G. L., Moffatt, S. D., Mitchell, J. D., Leung, A. N. 2003; 180 (4): 1182-1183

    View details for Web of Science ID 000181745500064

    View details for PubMedID 12646486

  • Angiographic classification of ovarian artery-to-uterine artery anastomoses: Initial observations in uterine fibroid embolization RADIOLOGY Razavi, M. K., Wolanske, K. A., Hwang, G. L., Sze, D. Y., Kee, S. T., Dake, M. D. 2002; 224 (3): 707-712

    Abstract

    To prospectively study and classify the anastomoses between the ovarian and uterine arteries in women undergoing uterine fibroid embolization, and to compare the presence of such with procedural failures and premature menopause.Angiographic ovarian artery-to-uterine artery anastomoses were studied in 76 consecutive patients undergoing uterine fibroid embolization. Mean patient age was 44.7 years (range, 29-56 years). Clinical follow-up consisted of a standard questionnaire. Procedural failure and complications were compared with the presence of various types of ovarian artery-to-uterine artery connections.Three types of anastomoses were identified. In type I (33 [21.7%] of 152 arteries), flow from the ovarian artery to the uterus was through anastomoses with the main uterine artery. In type II (six arteries [3.9%]), the ovarian artery supplied the fibroids directly. In type III (10 arteries [6.6%]), the major blood supply to the ovary was from the uterine artery. Seven patients (9%) were considered to have clinical failure, with three of the six women with type II anastomoses being in this group. Three of the five women who experienced menopause after fibroid embolization had bilateral ovarian artery-to-uterine artery anastomoses that were classified as high risk.Delineation of ovarian artery-to-uterine artery anastomosis is of practical relevance in avoiding nontarget ovarian embolization, in identification of those who would be at risk of uterine artery embolization or ovarian failure, and in those in whom the ovarian artery can be embolized safely.

    View details for DOI 10.1148/radiol.2243011513

    View details for Web of Science ID 000177621700013

    View details for PubMedID 12202703

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