Bio

Clinical Focus


  • Diagnostic Radiology
  • Neuroradiology
  • Brain Tumor Imaging
  • Vascular Imaging

Academic Appointments


  • Clinical Assistant Professor, Radiology

Administrative Appointments


  • Senator, School of Medicine, Faculty Senate (2015 - 2017)
  • Co-director, Medical Student Neuroradiology Clerkship (2015 - Present)
  • Associate Program Director, Radiology Residency (2016 - Present)

Honors & Awards


  • Research Scholar Grant, RSNA (2015-2017)
  • Grant, Musella Foundation for Brain Tumor Research (2015)
  • Angel Grant, Stanford Radiology (2013)
  • Chief Resident, Santa Clara Valley Medical Center (2009)
  • Dean’s Scholar for Outstanding Medical Student Thesis in Radiology, UCLA (2006)
  • Ceslo Gonzalez/Lopo Family Fellowship Award for Academic Excellence and Leadership, UCLA (2003)
  • Leadership Academy Scholarship, California Medical Association (2003)
  • Magna Cum Laude, UCR (2003)

Boards, Advisory Committees, Professional Organizations


  • Member, International Society for Magnetic Resonance in Medicine (ISMRM) (2013 - Present)
  • Member, American Society of Neuroradiology (ASNR) (2011 - Present)
  • Member, American College of Radiology (ACR) (2007 - Present)
  • Member, Radiological Society of North America (RSNA) (2006 - Present)

Professional Education


  • Medical Education:UCLA General Surgery Residency (2006) CA
  • Residency:Santa Clara Valley Medical Center Radiology Residency (2011) CA
  • Internship:Cedars Sinai Medical Center Pediatric Residency Ended 2004 (2007) CA
  • Board Certification, Neuroradiology, American Board of Radiology (2013)
  • Board Certification: Diagnostic Radiology, American Board of Radiology (2011)
  • Fellowship:Stanford University School of Medicine (2013) CA

Research & Scholarship

Current Research and Scholarly Interests


My clinical and research interests include brain tumor and vascular imaging in both the adult and pediatric populations, incorporating advanced MR imaging techniques and analyses using qualitative and quantitative methods.

Clinical Trials


  • BPM31510 in Treating Patients With Recurrent High-Grade Glioma Previously Treated With Bevacizumab Recruiting

    This phase I trial studies the side effects and best dose of ubidecarenone injectable nanosuspension (BPM31510) in treating patients with high-grade glioma (anaplastic astrocytoma or glioblastoma) that has come back and have been previously treated with bevacizumab. BPM31510 may stop the growth of tumor cells by blocking some of the enzymes needed for cell growth.

    View full details

  • Using Ferumoxytol-Enhanced MRI to Measure Inflammation in Patients With Brain Tumors or Other Conditions of the CNS Not Recruiting

    This pilot clinical trial study will assess the inflammatory response of brain tumors or other central nervous system conditions in pediatric and adult patients using ferumoxytol-enhanced MRI. Imaging features will be correlated with the number of inflammatory cells (macrophages) at histopathology. Determining the extent of inflammation associated with pathologies in the central nervous system may be helpful for diagnostic and prognostic purposes as well as monitoring treatment response of current and future immunotherapies.

    Stanford is currently not accepting patients for this trial. For more information, please contact Michael Iv, 650-723-4527.

    View full details

  • In Vivo Characterization of Macrophages in Pediatric Patients With Malignant Brain Tumors Using Ferumoxytol-enhanced MRI Recruiting

    This pilot early phase I trial studies how well ferumoxytol-enhanced magnetic resonance imaging (MRI) correlates with inflammatory (macrophage) responses in pediatric patients with malignant brain tumors. If there is good correlation, ferumoxytol-enhanced MRI can serve as a noninvasive imaging biomarker of inflammation.

    View full details

Publications

All Publications


  • High-resolution 3D volumetric contrast-enhanced MR angiography with a blood pool agent (ferumoxytol) for diagnostic evaluation of pediatric brain arteriovenous malformations. Journal of neurosurgery. Pediatrics Iv, M., Choudhri, O., Dodd, R. L., Vasanawala, S. S., Alley, M. T., Moseley, M., Holdsworth, S. J., Grant, G., Cheshier, S., Yeom, K. W. 2018: 1–10

    Abstract

    OBJECTIVE Patients with brain arteriovenous malformations (AVMs) often require repeat imaging with MRI or MR angiography (MRA), CT angiography (CTA), and digital subtraction angiography (DSA). The ideal imaging modality provides excellent vascular visualization without incurring added risks, such as radiation exposure. The purpose of this study is to evaluate the performance of ferumoxytol-enhanced MRA using a high-resolution 3D volumetric sequence (fe-SPGR) for visualizing and grading pediatric brain AVMs in comparison with CTA and DSA, which is the current imaging gold standard. METHODS In this retrospective cohort study, 21 patients with AVMs evaluated by fe-SPGR, CTA, and DSA between April 2014 and August 2017 were included. Two experienced raters graded AVMs using Spetzler-Martin criteria on all imaging studies. Lesion conspicuity (LC) and diagnostic confidence (DC) were assessed using a 5-point Likert scale, and interrater agreement was determined. The Kruskal-Wallis test was performed to assess the raters' grades and scores of LC and DC, with subsequent post hoc pairwise comparisons to assess for statistically significant differences between pairs of groups at p < 0.05. RESULTS Assigned Spetzler-Martin grades for AVMs on DSA, fe-SPGR, and CTA were not significantly different (p = 0.991). LC and DC scores were higher with fe-SPGR than with CTA (p < 0.05). A significant difference in LC scores was found between CTA and fe-SPGR (p < 0.001) and CTA and DSA (p < 0.001) but not between fe-SPGR and DSA (p = 0.146). A significant difference in DC scores was found among DSA, fe-SPGR, and CTA (p < 0.001) and between all pairs of the groups (p < 0.05). Interrater agreement was good to very good for all image groups (κ = 0.77-1.0, p < 0.001). CONCLUSIONS Fe-SPGR performed robustly in the diagnostic evaluation of brain AVMs, with improved visual depiction of AVMs compared with CTA and comparable Spetzler-Martin grading relative to CTA and DSA.

    View details for DOI 10.3171/2018.3.PEDS17723

    View details for PubMedID 29882734

  • Practical Pearl: Use of MRI to Differentiate Pseudo-subarachnoid Hemorrhage from True Subarachnoid Hemorrhage. Neurocritical care Ho, A. L., Sussman, E. S., Pendharkar, A. V., Iv, M., Hirsch, K. G., Fischbein, N. J., Dodd, R. L. 2018

    View details for DOI 10.1007/s12028-018-0547-3

    View details for PubMedID 29948997

  • Lobular capillary hemangioma of the mandible: A case report. Clinical imaging Chan, C., Iv, M., Fischbein, N., Dahmoush, H. 2018; 50: 246–49

    Abstract

    Lobular capillary hemangiomas are acquired benign vascular neoplasms which typically affect the skin and mucous membranes. While these lesions commonly involve the head and neck, particularly the oral cavity, there are no reports in the literature of lobular capillary hemangioma arising from the mandible. The diagnosis of such a rare entity can therefore be challenging, especially as it may mimic more aggressive lesions, including malignancy. We present a rare case of an 8-year-old male with a lobular capillary hemangioma of the mandible, highlighting its imaging features and discussing the differential diagnosis of primary mandibular lesions in the pediatric population.

    View details for DOI 10.1016/j.clinimag.2018.04.012

    View details for PubMedID 29704808

  • Can diffusion- and perfusion-weighted imaging alone accurately triage anterior circulation acute ischemic stroke patients to endovascular therapy? Journal of neurointerventional surgery Wolman, D. N., Iv, M., Wintermark, M., Zaharchuk, G., Marks, M. P., Do, H. M., Dodd, R. L., Albers, G. W., Lansberg, M. G., Heit, J. J. 2018

    Abstract

    Acute ischemic stroke (AIS) patients who benefit from endovascular treatment have a large vessel occlusion (LVO), small core infarction, and salvageable brain. We determined if diffusion-weighted imaging (DWI) and perfusion-weighted imaging (PWI) alone can correctly identify and localize anterior circulation LVO and accurately triage patients to endovascular thrombectomy (ET).This retrospective cohort study included patients undergoing MRI for the evaluation of AIS symptoms. DWI and PWI images alone were anonymized and scored for cerebral infarction, LVO presence and LVO location, DWI-PWI mismatch, and ET candidacy. Readers were blinded to clinical data. The primary outcome measure was accurate ET triage. Secondary outcomes were detection of LVO and LVO location.Two hundred and nineteen patients were included. Seventy-three patients (33%) underwent endovascular AIS treatment. Readers correctly and concordantly triaged 70 of 73 patients (96%) to ET (κ=0.938; P=0.855) and correctly excluded 143 of 146 patients (98%; P=0.942). DWI and PWI alone had a 95.9% sensitivity and a 98.4% specificity for accurate endovascular triage. LVO were accurately localized to the ICA/M1 segment in 65 of 68 patients (96%; κ=0.922; P=0.817) and the M2 segment in 18 of 20 patients (90%; κ=0.830; P=0.529).AIS patients with anterior circulation LVO are accurately identified using DWI and PWI alone, and LVO location may be correctly inferred from PWI. MRA omission may be considered to expedite AIS triage in hyperacute scenarios or may confidently supplant non-diagnostic or artifact-limited MRA.

    View details for DOI 10.1136/neurintsurg-2018-013784

    View details for PubMedID 29555872

  • Current Clinical State of Advanced Magnetic Resonance Imaging for Brain Tumor Diagnosis and Follow Up. Seminars in roentgenology Iv, M., Yoon, B. C., Heit, J. J., Fischbein, N., Wintermark, M. 2018; 53 (1): 45–61

    View details for DOI 10.1053/j.ro.2017.11.005

    View details for PubMedID 29405955

  • Conus Medullaris Dural Arteriovenous Fistula Arising From the Artery of the Filum Terminale: 2-Dimensional Operative Video. Operative neurosurgery (Hagerstown, Md.) Lamsam, L., Quon, J., Fischbein, N., Iv, M., Dodd, R., Ratliff, J. 2018

    View details for DOI 10.1093/ons/opx297

    View details for PubMedID 29444295

  • Pediatric Stroke Imaging. Pediatric neurology Khalaf, A., Iv, M., Fullerton, H., Wintermark, M. 2018

    Abstract

    Pediatric stroke is a distinct clinical entity as compared with that in adults due to its unique and diverse set of etiologies. Furthermore, the role and application of diagnostic imaging has specific constraints and considerations. The intention of this article is to review these concepts in a thorough manner to offer a pediatric stroke imaging framework that providers can employ when taking care of these patients.A comprehensive primary and secondary literature review was performed with specific attention to the common causes of pediatric stroke, appropriate use of neuroimaging, specific imaging findings, and developing techniques which may improve our ability to accurately diagnose these patients.Findings from this literature review were synthesized and summarized in order to thoroughly review the aforementioned concepts and outline the current consensus-based approach to diagnostic imaging in pediatric stroke. Furthermore, imaging findings drawn from cases which presented to our institution are demonstrated to familiarize readers with pediatric stroke neuroimaging.The challenges posed by pediatric stroke can be mitigated, in part by the thoughtful application of diagnostic imaging, with the ultimate hope of improving outcomes for these vulnerable patients.

    View details for DOI 10.1016/j.pediatrneurol.2018.05.008

    View details for PubMedID 30122281

  • Evaluation of Thick-Slab Overlapping MIP Images of Contrast-Enhanced 3D T1-Weighted CUBE for Detection of Intracranial Metastases: A Pilot Study for Comparison of Lesion Detection, Interpretation Time, and Sensitivity with Nonoverlapping CUBE MIP, CUBE, and Inversion-Recovery-Prepared Fast-Spoiled Gradient Recalled Brain Volume. AJNR. American journal of neuroradiology Yoon, B. C., Saad, A. F., Rezaii, P., Wintermark, M., Zaharchuk, G., Iv, M. 2018

    Abstract

    Early and accurate identification of cerebral metastases is important for prognostication and treatment planning although this process is often time consuming and labor intensive, especially with the hundreds of images associated with 3D volumetric imaging. This study aimed to evaluate the benefits of thick-slab overlapping MIPs constructed from contrast-enhanced T1-weighted CUBE (overlapping CUBE MIP) for the detection of brain metastases in comparison with traditional CUBE and inversion-recovery prepared fast-spoiled gradient recalled brain volume (IR-FSPGR-BRAVO) and nonoverlapping CUBE MIP.A retrospective review of 48 patients with cerebral metastases was performed at our institution from June 2016 to October 2017. Brain MRIs, which were acquired on multiple 3T scanners, included gadolinium-enhanced T1-weighted IR-FSPGR-BRAVO and CUBE, with subsequent generation of nonoverlapping CUBE MIP and overlapping CUBE MIP. Two blinded radiologists identified the total number and location of metastases on each image type. The Cohen κ was used to determine interrater agreement. Sensitivity, interpretation time, and lesion contrast-to-noise ratio were assessed.Interrater agreement for identification of metastases was fair-to-moderate for all image types (κ = 0.222-0.598). The total number of metastases identified was not significantly different across the image types. Interpretation time for CUBE MIPs was significantly shorter than for CUBE and IR-FSPGR-BRAVO, saving at least 50 seconds per case on average (P < .001). The mean lesion contrast-to-noise ratio for both CUBE MIPs was higher than for IR-FSPGR-BRAVO. The mean contrast-to-noise ratio for small lesions (<4 mm) was lower for nonoverlapping CUBE MIP (1.55) than for overlapping CUBE MIP (2.35). For both readers, the sensitivity for lesion detection was high for all image types but highest for overlapping CUBE MIP and CUBE (0.93-0.97).This study suggests that the use of overlapping CUBE MIP or nonoverlapping CUBE MIP for the detection of brain metastases can reduce interpretation time without sacrificing sensitivity, though the contrast-to-noise ratio of lesions is highest for overlapping CUBE MIP.

    View details for DOI 10.3174/ajnr.A5747

    View details for PubMedID 30093483

  • Tumefactive demyelination associated with developmental venous anomaly: Report of two cases CLINICAL IMAGING Ma, M., Chen, J. Y., Plowey, E. D., Fischbein, N., Iv, M. 2017; 43: 194-198

    Abstract

    We present two cases of tumefactive demyelination (TD) occurring in close association with a developmental venous anomaly (DVA). Our purpose is to describe the association between demyelinating lesions and venous anomalies, as only one case of TD associated with a DVA has been published in the literature. Appropriate recognition of this "do not touch" lesion may avoid invasive and potentially harmful procedures such as biopsy or resection.

    View details for DOI 10.1016/j.clinimag.2017.02.012

    View details for Web of Science ID 000401298400039

    View details for PubMedID 28364723

  • Resting-State BOLD MRI for Perfusion and Ischemia. Topics in magnetic resonance imaging Kroll, H., Zaharchuk, G., Christen, T., Heit, J. J., Iv, M. 2017; 26 (2): 91-96

    Abstract

    Advanced imaging techniques including computed tomography (CT) angiography, CT perfusion, magnetic resonance (MR) angiography, MR with diffusion- and perfusion-weighted imaging, and, more recently, resting-state BOLD (Blood Oxygen Level Dependent) functional MRI (rs-fMRI) are increasingly used to evaluate patients with acute ischemic stroke. Advanced imaging allows for identification of patients with ischemic stroke and determination of the size of infarcted and potentially salvageable tissue, all of which yield crucial information for proper stroke management. The addition of rs-fMRI for ischemia adds information at the microvascular level, thereby improving the understanding of pathophysiologic mechanisms of impaired cerebral perfusion and tissue oxygenation beyond the known concepts at the macrovascular level. As such, it may further delineate functional and dysfunctional neuronal networks, guide stroke interventions, and improve prognosis and monitoring of patient outcomes.

    View details for DOI 10.1097/RMR.0000000000000119

    View details for PubMedID 28277456

  • Radiomics in Brain Tumor: Image Assessment, Quantitative Feature Descriptors, and Machine-Learning Approaches. AJNR. American journal of neuroradiology Zhou, M., Scott, J., Chaudhury, B., Hall, L., Goldgof, D., Yeom, K. W., Iv, M., Ou, Y., Kalpathy-Cramer, J., Napel, S., Gillies, R., Gevaert, O., Gatenby, R. 2017

    Abstract

    Radiomics describes a broad set of computational methods that extract quantitative features from radiographic images. The resulting features can be used to inform imaging diagnosis, prognosis, and therapy response in oncology. However, major challenges remain for methodologic developments to optimize feature extraction and provide rapid information flow in clinical settings. Equally important, to be clinically useful, predictive radiomic properties must be clearly linked to meaningful biologic characteristics and qualitative imaging properties familiar to radiologists. Here we use a cross-disciplinary approach to highlight studies in radiomics. We review brain tumor radiologic studies (eg, imaging interpretation) through computational models (eg, computer vision and machine learning) that provide novel clinical insights. We outline current quantitative image feature extraction and prediction strategies with different levels of available clinical classes for supporting clinical decision-making. We further discuss machine-learning challenges and data opportunities to advance radiomic studies.

    View details for DOI 10.3174/ajnr.A5391

    View details for PubMedID 28982791

  • Clinical and Arterial Spin Labeling Brain MRI Features of Transitional Venous Anomalies. Journal of neuroimaging : official journal of the American Society of Neuroimaging Zhang, M., Telischak, N. A., Fischbein, N. J., Steinberg, G. K., Marks, M., Zaharchuk, G., Heit, J. J., Iv, M. 2017

    Abstract

    Transitional venous anomalies (TVAs) are rare cerebrovascular lesions that resemble developmental venous anomalies (DVAs), but demonstrate early arteriovenous shunting on digital subtraction angiography (DSA) without the parenchymal nidus of arteriovenous malformations (AVMs). We investigate whether arterial spin labeling (ASL) magnetic resonance imaging (MRI) can distinguish brain TVAs from DVAs and guide their clinical management.We conducted a single-center retrospective review of patients with brain parenchymal DVA-like lesions with increased ASL signal on MRI. Clinical histories and follow-up information were obtained. Two readers assessed ASL signal location relative to the vascular lesion on MRI and, if available, the presence of arteriovenous shunting on DSA.Thirty patients with DVA-like lesions with increased ASL signal were identified. Clinical symptoms prompted MRI evaluation in 83%. Symptoms did not localize to the venous anomaly in 90%. Ten percent presented with acute symptoms, only one of whom presented with hemorrhage. ASL signal in relation to the venous anomaly was identified in: 50% in the adjacent parenchyma, 33% in the lesion, 7% in a distal draining vein/sinus, and 10% in at least two of these sites. Follow-up DSA confirmed arteriovenous shunting in 71% of ASL-positive venous anomalies. Interrater agreement was very good (κ = .81-1.0, P < .001).A DVA-like lesion with increased ASL signal likely represents a TVA with arteriovenous shunting. Our study indicates that these lesions are usually incidentally detected and have a lower risk of hemorrhage than AVMs. ASL-MRI may be a useful tool to identify TVAs and guide further management of patients with TVAs.

    View details for DOI 10.1111/jon.12487

    View details for PubMedID 29205641

  • Imaging of Intracranial Hemorrhage. Journal of stroke Heit, J. J., Iv, M., Wintermark, M. 2017; 19 (1): 11-27

    Abstract

    Intracranial hemorrhage is common and is caused by diverse pathology, including trauma, hypertension, cerebral amyloid angiopathy, hemorrhagic conversion of ischemic infarction, cerebral aneurysms, cerebral arteriovenous malformations, dural arteriovenous fistula, vasculitis, and venous sinus thrombosis, among other causes. Neuroimaging is essential for the treating physician to identify the cause of hemorrhage and to understand the location and severity of hemorrhage, the risk of impending cerebral injury, and to guide often emergent patient treatment. We review CT and MRI evaluation of intracranial hemorrhage with the goal of providing a broad overview of the diverse causes and varied appearances of intracranial hemorrhage.

    View details for DOI 10.5853/jos.2016.00563

    View details for PubMedID 28030895

  • Reducing Functional MR Imaging Acquisition Times by Optimizing Workflow RADIOGRAPHICS Chwang, W. B., Iv, M., Smith, J., Kalnins, A., Mickelsen, J., Bammer, R., Fleischmann, D., Larson, D. B., Wintermark, M., Zeineh, M. 2017; 37 (1): 315-321

    Abstract

    Functional magnetic resonance (MR) imaging is a complex, specialized examination that is able to noninvasively measure information critical to patient care such as hemispheric language lateralization ( 1 ). Diagnostic functional MR imaging requires extensive patient interaction as well as the coordinated efforts of the entire health care team. We observed in our practice at an academic center that the times to perform functional MR imaging examinations were excessively lengthy, making scheduling of the examination difficult. The purpose of our project was to reduce functional MR imaging acquisition times by increasing the efficiency of our workflow, using specific quality tools to drive improvement of functional MR imaging. We assembled a multidisciplinary team and retrospectively reviewed all functional MR imaging examinations performed at our institution from January 2013 to August 2015. We identified five key drivers: (a) streamlined protocols, (b) consistent patient monitoring, (c) clear visual slides and audio, (d) improved patient understanding, and (e) minimized patient motion. We then implemented four specific interventions over a period of 10 months: (a) eliminating intravenous contrast medium, (b) reducing repeated language paradigms, (c) updating technologist and physician checklists, and (d) updating visual slides and audio. Our mean functional MR imaging acquisition time was reduced from 76.3 to 53.2 minutes, while our functional MR imaging examinations remained of diagnostic quality. As a result, we reduced our routine scheduling time for functional MR imaging from 2 hours to 1 hour, improving patient comfort and satisfaction as well as saving time for additional potential MR imaging acquisitions. Our efforts to optimize functional MR imaging workflow constitute a practice quality improvement project that is beneficial for patient care and can be applied broadly to other functional MR imaging practices. (©)RSNA, 2017.

    View details for DOI 10.1148/rg.2017160035

    View details for Web of Science ID 000397205200021

  • Magnetic resonance perfusion image features uncover an angiogenic subgroup of glioblastoma patients with poor survival and better response to antiangiogenic treatment. Neuro-oncology Liu, T. T., Achrol, A. S., Mitchell, L. A., Rodriguez, S. A., Feroze, A., Kim, C., Chaudhary, N., Gevaert, O., Stuart, J. M., Harsh, G. R., Chang, S. D., Rubin, D. L. 2016

    Abstract

    In previous clinical trials, antiangiogenic therapies such as bevacizumab did not show efficacy in patients with newly diagnosed glioblastoma (GBM). This may be a result of the heterogeneity of GBM, which has a variety of imaging-based phenotypes and gene expression patterns. In this study, we sought to identify a phenotypic subtype of GBM patients who have distinct tumor-image features and molecular activities and who may benefit from antiangiogenic therapies.Quantitative image features characterizing subregions of tumors and the whole tumor were extracted from preoperative and pretherapy perfusion magnetic resonance (MR) images of 117 GBM patients in 2 independent cohorts. Unsupervised consensus clustering was performed to identify robust clusters of GBM in each cohort. Cox survival and gene set enrichment analyses were conducted to characterize the clinical significance and molecular pathway activities of the clusters. The differential treatment efficacy of antiangiogenic therapy between the clusters was evaluated.A subgroup of patients with elevated perfusion features was identified and was significantly associated with poor patient survival after accounting for other clinical covariates (P values <.01; hazard ratios > 3) consistently found in both cohorts. Angiogenesis and hypoxia pathways were enriched in this subgroup of patients, suggesting the potential efficacy of antiangiogenic therapy. Patients of the angiogenic subgroups pooled from both cohorts, who had chemotherapy information available, had significantly longer survival when treated with antiangiogenic therapy (log-rank P=.022).Our findings suggest that an angiogenic subtype of GBM patients may benefit from antiangiogenic therapy with improved overall survival.

    View details for DOI 10.1093/neuonc/now270

    View details for PubMedID 28007759

  • Diffusion Tensor Imaging of TBI: Potentials and Challenges. Topics in magnetic resonance imaging Douglas, D. B., Iv, M., Douglas, P. K., Anderson, A., Vos, S. B., Bammer, R., Zeineh, M., Wintermark, M. 2015; 24 (5): 241-251

    Abstract

    Neuroimaging plays a critical role in the setting in traumatic brain injury (TBI). Diffusion tensor imaging (DTI) is an advanced magnetic resonance imaging technique that is capable of providing rich information on the brain's neuroanatomic connectome. The purpose of this article is to systematically review the role of DTI and advanced diffusion techniques in the setting of TBI, including diffusion kurtosis imaging (DKI), neurite orientation dispersion and density imaging, diffusion spectrum imaging, and q-ball imaging. We discuss clinical applications of DTI and review the DTI literature as it pertains to TBI. Despite the continued advancements in DTI and related diffusion techniques over the past 20 years, DTI techniques are sensitive for TBI at the group level only and there is insufficient evidence that DTI plays a role at the individual level. We conclude by discussing future directions in DTI research in TBI including the role of machine learning in the pattern classification of TBI.

    View details for DOI 10.1097/RMR.0000000000000062

    View details for PubMedID 26502306

  • Intensity-Corrected Dual-Echo Echo-Planar Imaging (DE-EPI) for Improved Pediatric Brain Diffusion Imaging PLOS ONE Yeom, K. W., Straka, M., Iv, M., Moseley, M. E., Barnes, P. D., Skare, S., Holdsworth, S. J. 2015; 10 (6)

    Abstract

    Here we investigate the utility of a dual-echo Echo-Planar Imaging (DE-EPI) Diffusion Weighted Imaging (DWI) approach to improve lesion conspicuity in pediatric imaging. This method delivers two 'echo images' for one diffusion-preparation period. We also demonstrate how the echoes can be utilized to remove transmit/receive coil-induced and static magnetic field intensity modulations on both echo images, which often mimic pathology and thereby pose diagnostic challenges. DE-EPI DWI data were acquired in 18 pediatric patients with abnormal diffusion lesions, and 46 pediatric patient controls at 3T. Echo1 [TE = 45ms] and Echo2 [TE = 86ms] were corrected for signal intensity variation across the images by exploiting the images equivalent coil-sensitivity and susceptibility-induced modulations. Two neuroradiologists independently reviewed Echo1 and Echo2 and their intensity-corrected variants (cEcho1 and cEcho2) on a 7-point Likert scale, with grading on lesion conspicuity diagnostic confidence. The apparent diffusion coefficient (ADC) map from Echo1 was used to validate presence of true pathology. Echo2 was unanimously favored over Echo1 for its sensitivity for detecting acute brain injury, with a mean respective lesion conspicuity of 5.7/4.4 (p < 0.005) and diagnostic confidence of 5.1/4.3 (p = 0.025). cEcho2 was rated higher than cEcho1, with a mean respective lesion conspicuity of 5.5/4.3 (p < 0.005) and diagnostic confidence of 5.4/4.4 (p < 0.005). cEcho2 was favored over all echoes for its diagnostic reliability, particularly in regions close to the head coil. This work concludes that DE-EPI DWI is a useful alternative to conventional single-echo EPI DWI, whereby Echo2 and cEcho2 allows for improved lesion detection and overall higher diagnostic confidence.

    View details for DOI 10.1371/journal.pone.0129325

    View details for Web of Science ID 000356327000065

    View details for PubMedID 26069959

  • Congenital Brain Malformations in the Neonatal and Early Infancy Period SEMINARS IN ULTRASOUND CT AND MRI Kim, C., Yeom, K. W., Iv, M. 2015; 36 (2): 97-119

    Abstract

    Congenital brain malformations are a major cause of morbidity and mortality in pediatric patients who are younger than 2 years. Optimization of patient care requires accurate diagnosis, which can be challenging as congenital brain malformations include an extensive variety of anomalies. Radiologic imaging helps to identify the malformations and to guide management. Understanding radiologic findings necessitates knowledge of central nervous system embryogenesis. This review discusses the imaging of congenital brain malformations encountered in patients who are younger than 2 years in the context of brain development.

    View details for DOI 10.1053/j.sult.2015.01.003

    View details for Web of Science ID 000355575300002

    View details for PubMedID 26001941

  • Imaging Neck Masses in the Neonate and Young Infant SEMINARS IN ULTRASOUND CT AND MRI Tranvinh, E., Yeom, K. W., Iv, M. 2015; 36 (2): 120-137

    Abstract

    Head and neck masses occurring in the neonatal period and early infancy consist of vascular tumors, vascular malformations, benign and malignant soft tissue tumors, and other developmental lesions. Although some lesions can be diagnosed on clinical grounds, others can only be diagnosed by imaging. Beyond diagnosis, imaging plays a significant role in evaluating the location and extent of a lesion for possible intervention. In this article, we review the clinical presentation and imaging appearance of common and rare masses that may be encountered in this age group. We also highlight current treatment strategies for specific lesions.

    View details for DOI 10.1053/j.sult.2015.01.004

    View details for Web of Science ID 000355575300003

    View details for PubMedID 26001942

  • Association of developmental venous anomalies with perfusion abnormalities on arterial spin labeling and bolus perfusion-weighted imaging. Journal of neuroimaging Iv, M., Fischbein, N. J., Zaharchuk, G. 2015; 25 (2): 243-250

    Abstract

    To investigate the frequency and characteristics of developmental venous anomaly (DVA)-associated perfusion abnormalities on arterial spin labeling (ASL) and bolus perfusion-weighted imaging (PWI) and discuss their potential causes.We reviewed brain MR reports to identify all DVAs reported on studies performed between 2009 and 2012. DVA location and findings on PWI and/or ASL imaging were assessed by visual inspection. Sizes of DVAs were categorized as small (<15 mm), medium (15-25 mm), and large (>25 mm). For ASL, signal in the DVA, surrounding parenchyma, or associated draining vein was recorded. For PWI, changes on hemodynamic maps (cerebral blood volume [CBV], cerebral blood flow [CBF], mean transit time [MTT], and normalized time-to-peak of the residue function [Tmax]) were evaluated. Coexisting vascular malformations in association with DVAs were also identified.Six hundred and fifty-two DVAs were identified in 632 subjects. Of these, 121 underwent both perfusion modalities, 15 only PWI, and 127 only ASL. ASL abnormalities were seen in 21/248 (8%), including signal in a draining vein (2/21, 10%), in the DVA (11/21, 52%), and in the parenchyma (8/21, 38%). On PWI, the majority of DVAs demonstrated abnormalities (108/136, 79%), typically increased CBF, CBV, MTT, and Tmax. There was no association between DVA size and presence of ASL signal (P = .836). Borderline statistical significance was found between DVA size and presence of PWI abnormality (P = .046). No relationship was found between the presence of a coexisting vascular malformation and presence of ASL (P = .468) or PWI abnormality (P = .745).Perfusion changes with DVAs are common on PWI but uncommon on ASL. PWI findings are expected based on the anatomy and physiology of DVAs and are accentuated by gradient echo acquisition. DVAs with intrinsic ASL signal or signal in draining veins may be associated with arteriovenous shunting (transitional lesions).

    View details for DOI 10.1111/jon.12119

    View details for PubMedID 24717021

  • Imaging Manifestations of Primary and Disseminated Coccidioidomycosis Applied Radiology Gupta, N. A., Iv, M., Pandit, R. P., Patel, M. R. 2015; 44 (2): 9-21
  • Clinical applications of iron oxide nanoparticles for magnetic resonance imaging of brain tumors NANOMEDICINE Iv, M., Telischak, N., Feng, D., Holdsworth, S. J., Yeom, K. W., Daldrup-Link, H. E. 2015; 10 (6): 993-1018

    Abstract

    Current neuroimaging provides detailed anatomic and functional evaluation of brain tumors, allowing for improved diagnostic and prognostic capabilities. Some challenges persist even with today's advanced imaging techniques, including accurate delineation of tumor margins and distinguishing treatment effects from residual or recurrent tumor. Ultrasmall superparamagnetic iron oxide nanoparticles are an emerging tool that can add clinically useful information due to their distinct physiochemical features and biodistribution, while having a good safety profile. Nanoparticles can be used as a platform for theranostic drugs, which have shown great promise for the treatment of CNS malignancies. This review will provide an overview of clinical ultrasmall superparamagnetic iron oxides and how they can be applied to the diagnostic and therapeutic neuro-oncologic setting.

    View details for DOI 10.2217/NNM.14.203

    View details for Web of Science ID 000352806000009

    View details for PubMedID 25867862

  • Prolonged survival of patients with non-small-cell lung cancer with leptomeningeal carcinomatosis in the modern treatment era. Clinical lung cancer Riess, J. W., Nagpal, S., Iv, M., Zeineh, M., Gubens, M. A., Ramchandran, K., Neal, J. W., Wakelee, H. A. 2014; 15 (3): 202-206

    Abstract

    Leptomeningeal carcinomatosis (LM) is a severe complication of non-small-cell lung cancer (NSCLC) historically associated with poor prognosis. New chemotherapeutic and targeted treatments could potentially affect the natural history of LM.Patients with a pathologic diagnosis of NSCLC with LM treated at Stanford between 2003 and 2011 were identified via institutional databases and medical records. LM was defined by cerebrospinal fluid (CSF) that was positive for malignant cells or by LM enhancement on magnetic resonance imaging with gadolinium contrast. Retrospective, landmark analyses were performed to estimate survival. Statistical analyses were performed using SAS Enterprise Guide, version 4.3.LM was identified in 30 patients. All cases were adenocarcinoma; 60% of patients had a known or suspected driver mutation. The mean age was 58 years. Of the 30 patients, 67% were women; 70% were nonsmokers; 27% initially presented with LM; 84% received systemic treatment at or after development of LM; and 53% of these patients received modern systemic therapy for their LM, defined as a regimen containing pemetrexed, bevacizumab, or a tyrosine kinase inhibitor. Mean overall survival after LM diagnosis was 6 months (95% CI, 3-12). Patients who received modern systemic therapy for LM had decreased hazard of death (hazard ratio [HR], 0.24; P = .007).In this retrospective, single-institution analysis, median survival with LM was higher compared with historical experience. Patients who received modern systemic therapy for their LM had particularly good outcomes. These data provide evidence for improving survival outcomes in the modern treatment era for this difficult-to-treat complication.

    View details for DOI 10.1016/j.cllc.2013.12.009

    View details for PubMedID 24524822

  • Imaging Spectrum of CNS Coccidioidomycosis: Prevalence and Significance of Concurrent Brain and Spinal Disease AMERICAN JOURNAL OF ROENTGENOLOGY Lammering, J. C., Iv, M., Gupta, N., Pandit, R., Patel, M. R. 2013; 200 (6): 1334-1346

    Abstract

    The purpose of this study was to evaluate the prevalence and significance of concurrent coccidioidal brain and intraspinal disease.We conducted a retrospective imaging review of 23 patients with proven coccidioidal CNS meningitis.All patients had intracranial abnormalities, and 86% (19/22) who underwent spinal imaging had signs of intraspinal disease, including leptomeningeal enhancement (84%), arachnoiditis (63%), and cord signal abnormalities (37%); seven of 15 patients (47%) who underwent myelography had complete spinal blocks.The high prevalence of concurrent brain and intraspinal coccidioidomycosis supports a low threshold for spinal imaging.

    View details for DOI 10.2214/AJR.12.9264

    View details for Web of Science ID 000319447700046

    View details for PubMedID 23701073

  • Comparison of Readout-Segmented Echo-Planar Imaging (EPI) and Single-Shot EPI in Clinical Application of Diffusion-Weighted Imaging of the Pediatric Brain. AJR. American journal of roentgenology Yeom, K. W., Holdsworth, S. J., Van, A. T., Iv, M., Skare, S., Lober, R. M., Bammer, R. 2013; 200 (5): W437-43

    View details for DOI 10.2214/AJR.12.9854

    View details for PubMedID 23617511

  • Informatics in Radiology Use of a Macro Scripting Editor to Facilitate Transfer of Dual-Energy X-ray Absorptiometry Reports into an Existing Departmental Voice Recognition Dictation System RADIOGRAPHICS Iv, M., Patel, M. R., Santos, A., Kang, Y. S. 2011; 31 (4): 1181-1189

    Abstract

    The process of verbally reporting or manually retyping numeric data generated at dual-energy x-ray absorptiometry (DXA) involves numerous pitfalls. With use of a macro scripting editor, a customized macro was created to automate the transfer of data generated by a DXA scanner into a structured voice recognition dictation system without requiring radiologists to type in a medical record number or accession number to identify the study. A preliminary report is generated with use of software for a DXA unit and a customized template that includes numeric and qualitative assessments of osteoporosis as well as data from prior studies if available. A customized macro is then invoked by the macro scripting editor, which selectively transfers the report from the draft document into the voice recognition dictation system, thereby producing a final structured diagnostic report. All of the radiologists surveyed to evaluate this automated method reported ease of software use and greater efficiency in report production. In addition, a random audit of the 800 DXA scans that have been reported with this technique demonstrated no reports generated under an incorrect accession number and no incorrect transfer of data. Automated DXA reporting is now the preferred method of dictation at the authors' institution and represents an inexpensive, accurate, and customizable means of DXA reporting.

    View details for DOI 10.1148/rg.314105741

    View details for Web of Science ID 000292867000023

    View details for PubMedID 21546554

  • Left ventricular ejection fraction using 64-slice CT coronary angiography and new evaluation software: initial experience BRITISH JOURNAL OF RADIOLOGY Krishnam, M. S., Tomasian, A., Iv, M., Ruehm, S. G., Salieh, R., Panknin, C., Goldin, J. G. 2008; 81 (966): 450-455

    Abstract

    The purpose of this study was to evaluate the feasibility and reliability of software-based quantification of left ventricular function using 64-slice CT coronary angiography. Data were collected from 26 subjects who underwent a 64-slice coronary CT angiography study. Two volumetric data sets at end diastole and end systole were reconstructed from each scan by means of retrospective electrocardiogram gating. Data sets were evaluated with a prototype of now commercially available software (Syngo Circulation I; Siemens Medical Solutions, Erlangen, Germany), which automatically segments the blood volume in the left ventricle after the user defines the mitral valve plane and any point within the ventricle. After segmentation of the blood pool in end systole and end diastole, the software automatically measures end systolic and end diastolic volume and calculates stroke volume and ejection fraction (EF). Two readers processed all CT data sets twice to assess for intra- and inter-observer variation. In addition, CT EF measurements were compared with those obtained by clinical echocardiography. Intra-observer variation for the calculated EF with CT were 13.6% and 15.6% for Readers 1 and 2, respectively. No significant difference in left ventricular functional parameters on CT existed between the readers (p > 0.05). A Bland-Altman plot revealed a slight mean difference between EF measurements on CT and echocardiography, with all differences falling within two standard deviations of the mean in the setting of wide limits of agreement. In conclusion, assessment of left ventricular EF from CT coronary data using the new analysis software is rapid and easy. The software is user-friendly and provides good reproducibility for EF measurements with CT.

    View details for DOI 10.1259/bjr/54748900

    View details for Web of Science ID 000257011800004

    View details for PubMedID 18347027

  • Cardiac hemangioma: Features on cardiovascular magnetic resonance JOURNAL OF CARDIOVASCULAR MAGNETIC RESONANCE Tomasian, A., Iv, M., Lai, C., Jalili, M., Krishnam, M. S. 2007; 9 (6): 873-876

    Abstract

    We present a case of cardiac capillary hemangioma in a patient who presented with a history of recurrent episodes of syncope. Cardiovascular magnetic resonance played an important role in the diagnosis of cardiac hemangioma in our patient.

    View details for DOI 10.1080/10976640701693642

    View details for Web of Science ID 000251394000007

    View details for PubMedID 18066746

  • Pyridines in cigarette smoke inhibit hamster oviductal functioning in picomolar doses REPRODUCTIVE TOXICOLOGY Riveles, K., Iv, M., Arey, J., Talbot, P. 2003; 17 (2): 191-202

    Abstract

    Past studies showed that chemicals in cigarette smoke inhibit oviductal functioning in vivo and in vitro. The purposes of this study were to identify individual toxicants in cigarette smoke solutions that inhibit various aspects of oviductal functioning and to determine their effective doses using in vitro bioassays. Solid phase extraction and gas chromatography-mass spectrometry (GC-MS) were used to identify individual chemicals in mainstream (MS) and sidestream (SS) cigarette smoke solutions. Pyridines, which were the most abundant class of compounds identified, were purchased, assayed for purity, and tested in dose-response studies on hamster oviducts. The lowest observable adverse effect level was determined for each pyridine derivative using the oocyte pick-up rate, ciliary beat frequency, and infundibular muscle contraction assays. 2-Methylpyridine, 4-methylpyridine, 2-ethylpyridine, 3-ethylpyridine, and 4-vinylpyridine were inhibitory at picomolar concentrations in all assays. This work shows picomolar doses of pyridines with single methyl or ethyl substitutions significantly inhibit oviductal functioning raising questions regarding the safety of these compounds.

    View details for DOI 10.1016/S0890-6238(02)00150-8

    View details for Web of Science ID 000182233800007

    View details for PubMedID 12642152