A5067263462- Advanced MRI Techniques and Applications
- MRI in cancer diagnosis
- Cardiac Imaging and Diagnostics
- Lanthanide and Transition Metal Complexes
- Advanced Neuroimaging Techniques and Applications
- Cerebrovascular and Carotid Artery Diseases
- Renal and Vascular Pathologies
- Cardiovascular Function and Risk Factors
- Lymphatic System and Diseases
- Venous Thromboembolism Diagnosis and Management
- Cardiac Valve Diseases and Treatments
- Cardiovascular and Diving-Related Complications
- Radiation Dose and Imaging
- Acute Ischemic Stroke Management
- Radiomics and Machine Learning in Medical Imaging
- NMR spectroscopy and applications
- Liver Disease Diagnosis and Treatment
- Atomic and Subatomic Physics Research
- Prostate Cancer Diagnosis and Treatment
- Diagnosis and Treatment of Venous Diseases
- Advanced X-ray and CT Imaging
- Medical Imaging Techniques and Applications
- Lymphatic Disorders and Treatments
- Medical Imaging and Pathology Studies
- Radiology practices and education
University of Colorado Anschutz Medical Campus
2019-2024
University of Washington
2011-2023
University of Colorado Denver
2018-2021
University of Pennsylvania
2020
VA Puget Sound Health Care System
2002-2017
Seattle University
2016
University of Washington Medical Center
2006-2015
The University of Queensland
2012
Duke Medical Center
1988-2005
Duke University
1991-2005
Background: Timely, accurate detection of renal artery stenosis is important because this disorder may be a potentially curable cause hypertension and impairment. Objective: To determine the validity computed tomographic angiography (CTA) magnetic resonance (MRA) compared with digital subtraction (DSA) for stenosis. Design: Prospective multicenter comparative study conducted from 1998 to 2001. Two panels 3 observers judged CTA MRA image data were blinded all other results. Digital images...
Background— Both transthoracic echocardiography (TTE) and cardiac magnetic resonance (CMR) imaging allow quantification of chronic aortic regurgitation (AR) mitral (MR). We hypothesized that CMR measurement regurgitant volume (RVol) is more reproducible than TTE. Methods Results— TTE performed on the same day in 57 prospectively enrolled adults (31 with AR, 26 MR) were measured by 2 independent physicians. RVol AR was calculated as Doppler left ventricular outflow minus inflow stroke volume....
The optimum infusion timing and k-space ordering for obtaining gadolinium-enhanced three-dimensional MR angiograms was determined through computer modeling using temporal contrast characteristics obtained from patient gadolinium data. effects of bolus were evaluated by varying the relationship between peak intravascular concentration time at which center k space acquired (tck) sequential centric acquisition techniques. Flow phantom experiments performed to validate theoretical computations....
To improve gadolinium-enhanced magnetic resonance (MR) angiogram quality by automatically synchronizing acquisition of central k-space image data with the arterial phase contrast material bolus infusion.A spin-echo pulse sequence orthogonal 90 degrees and 180 pulses was used to monitor signal in a single 4 x 12-cm voxel that encompassed segment aorta. An increase corresponded arrival gadolinium trigger three-dimensional, spoiled gradient-echo abdominal MR angiography 50 adult...
Cryptogenic stroke is associated with an increased prevalence of patent foramen ovale. The Paradoxical Emboli From Large Veins in Ischemic Stroke (PELVIS) study hypothesized that patients cryptogenic have pelvic deep venous thrombosis (DVT).At 5 sites, 18 to 60 years age received MRI venogram (MRV) the pelvis within 72 hours new symptom onset. Clinical data were then determined. Radiologists blinded clinical later read scans.The 95 who met entry criteria scanned. Their mean+/-SD was 46+/-10...
After studying this article, the participant should be able to: 1. Discuss key points in diagnosing lymphedema. 2. Understand imaging modalities that facilitate diagnosis and surgical planning. 3. Appreciate indications for both physiologic ablative procedures. 4. Recognize potential role of lymphaticovenular anastomosis vascularized lymph node transfer treatment patients with lymphedema.Lymphedema is an incurable disease caused by insufficient lymphatic drainage leading to abnormal...
Abstract The purpose of the study was to investigate use a dextran‐coated ultrasmall superparamagnetic iron oxide (USPIO) as blood pool contrast agent for thoracic and abdominal MR angiography. Abdominal angiography performed in six healthy volunteers using two‐dimensional three‐dimensional spoiled gradient echo (SPGR) sequences before after intravenous administration USPIO. Doses ranged from 1.1 2.6 mg Fe/kg. Flip angle varied 20 60°. Subjective image quality, analysis signal‐to‐noise ratio...
Purpose To investigate performance in detectability of small (≤1 cm) low-contrast hypoattenuating focal lesions by using filtered back projection (FBP) and iterative reconstruction (IR) algorithms from two major CT vendors across a range 11 radiation exposures. Materials Methods A phantom consisting 21 objects (seven sizes between 2.4 10.0 mm, three contrast levels) embedded into liver-equivalent background was scanned at exposures (volume dose index range, 0.5–18.0 mGy; size-specific...
ABSTRACT. The effect of combined morphologic and functional magnetic resonance (MR) imaging on the interobserver intermodality variability for grading renal artery stenosis is assessed. In a randomized, blinded tricenter analysis, seven readers evaluated 43 arteries x-ray digital subtraction angiography (DSA), 3D-Gadolinium MR (3D-Gd-MRA), cine phase-contrast flow measurement (PC-flow), analysis last two. Interobserver was assessed as well regional vessel visibility. Intermodality analyzed...
Abstract Purpose To use the parallel imaging technique, sensitivity encoding (SENSE), to increase spatial resolution and decrease venous contamination in peripheral magnetic resonance angiography (MRA). Materials Methods Moving table, single‐bolus contrast‐enchanced (CE) ‐MRA was performed on nine patients. Manual table movement combined with SENSE upper station allowed for more rapid overall scan coverage such that acquisition of lower began 34 seconds after aortic contrast arrival. True...
Abstract Purpose: To compare nongated three‐dimensional (3D) contrast‐enhanced magnetic resonance angiography (CE‐MRA) with 3D‐navigated cardiac‐gated steady‐state free‐precession bright blood (3D‐nav SSFP) and noncontrast 2D techniques for ascending aorta dimension measurements. Materials Methods: Twenty‐five clinical exams were reviewed to evaluate the at 1.5T using: breathhold cine (SSFP), cardiac‐triggered T2 black (T2 BB), axial 3D‐nav SSFP, 3D CE‐MRA. Three radiologists independently...
Abstract Purpose To explore the use of breath‐hold and navigator‐gated noncontrast Steady State Free Precession (SSFP) MR angiography (MRA) protocols for evaluation renal artery stenosis (RAS). Materials Methods Twenty patients referred to rule out RAS were imaged using two one SSFP MRA sequences. All underwent contrast‐enhanced (CE‐MRA). Two radiologists evaluated all sequences both qualitatively (blur, artifacts, reader confidence) quantitatively (maximum stenosis). Using CE‐MRA as truth,...
Abstract Ferumoxytol is an iron‐containing parenteral treatment for iron deficiency anemia that was recently approved by the Food and Drug Administration. The in form of a superparamagnetic oxide causes T1, T2, T2* shortening on magnetic resonance imaging (MRI). Furthermore, drug has long intravascular half‐life 14–15 hours; standard dose can affect MRI days to months. We describe case which patient underwent contrast‐enhanced liver 2 after receiving ferumoxytol, unknown radiology team....
OBJECTIVE. The purpose of this study was to determine the incidence nephrogenic systemic fibrosis (NSF) in patients with chronic kidney disease (CKD) and moderate-to-severe impairment function who had not previously been exposed gadolinium-based contrast agents (GBCAs) or referred undergo contrast-enhanced MRI gadobenate dimeglumine gadoteridol.
Abstract Purpose To study the potential detrimental effects of renal motion on breath‐hold three‐dimensional contrast‐enhanced (CE) magnetic resonance angiography (MRA). Materials and Methods A computer model simulating linear was applied to MRA pulse sequences. Subsequently, whether present, 24 patients being evaluated for possible renovascular hypertension underwent a nonenhanced single slice two‐dimensional dynamic turbo field‐echo imaging (MRI) scan with typical duration 32 seconds. This...
Abstract This paper describes a new MR imaging technique termed Modified Stejskal Tanner versus Flow Compensation (MST/FC) for the separation of diffusion and microcirculatory flow. The theory behind sequence is explained, along with five‐component model microcirculation applicable to any “perfusion” technique. Phantom data presented showing that (1) effects can be matched between MST FC (suggesting possibility flow‐compensated imaging), (2) quantitative method separating slow (<0.25...