A5011076741- Advanced MRI Techniques and Applications
- Fetal and Pediatric Neurological Disorders
- MRI in cancer diagnosis
- Ultrasound Imaging and Elastography
- Congenital Heart Disease Studies
- Cardiac Valve Diseases and Treatments
- Aortic Disease and Treatment Approaches
- Cardiac Imaging and Diagnostics
- Cardiovascular Function and Risk Factors
- Atomic and Subatomic Physics Research
- Liver Disease Diagnosis and Treatment
- Neonatal and fetal brain pathology
- Elasticity and Material Modeling
- Cardiovascular Health and Disease Prevention
- Cerebrovascular and Carotid Artery Diseases
- Advanced Neuroimaging Techniques and Applications
- Lipoproteins and Cardiovascular Health
- Aortic aneurysm repair treatments
- Pregnancy and preeclampsia studies
- Cerebral Venous Sinus Thrombosis
- Medical Imaging Techniques and Applications
- Microscopic Colitis
- Radiomics and Machine Learning in Medical Imaging
- Traumatic Brain Injury and Neurovascular Disturbances
- Electrical and Bioimpedance Tomography
Amsterdam University Medical Centers
2021-2025
University of Amsterdam
2023-2025
Hospital for Sick Children
2017-2022
University of Toronto
2020-2021
SickKids Foundation
2020-2021
Sinai Health System
2021
University of Wisconsin–Madison
2012-2016
University of Auckland
2016
Umeå University
2015
Abstract Purpose: To validate a novel approach for accelerated four‐dimensional phase contrast MR imaging (4D PC‐MRI) with an extended range of velocity sensitivity. Materials and Methods: 4D PC‐MRI data were acquired radially undersampled trajectory (PC‐VIPR). A dual V enc (dV ) processing algorithm was implemented to investigate the potential scan time savings while providing improved velocity‐to‐noise ratio. Flow measurements compared flow pump, conventional 2D PC MR, single in chest 10...
Purpose To introduce and demonstrate a method for unwrapping 4D flow data by utilizing continuity constraints in all four available dimensions. Materials Methods A Laplacian-based algorithm phase was expanded to unwrap along the temporal dimension addition three spatial The tested on simulated blood under varying vessel diameters velocity encoding (Venc) values. also aorta of five volunteers, with wrapped acquired Venc = 80 cm/s 40 cm/s. Unwrapping performance measured visually comparison...
Purpose To describe, validate, and implement a centerline processing scheme (CPS) for semiautomated segmentation quantification in carotid siphons of healthy subjects. 4D flow MRI enables blood measurement all major cerebral arteries with one scan. Clinical translational hurdles are time demanding postprocessing user‐dependence induced variability during analysis. Materials Methods A CPS data was developed to automatically separate artery trees. Flow parameters were quantified at planes...
To date it has not been possible to obtain a comprehensive 3D assessment of fetal hemodynamics because the technical challenges inherent in imaging small cardiac structures, movement fetus during data acquisition, and difficulty fusing from multiple cycles when gating signal is absent. Here we propose combination volumetric velocity-sensitive cardiovascular magnetic resonance ("4D flow" CMR) specialized animal preparation (catheters monitor heart rate, anesthesia immobilize mother fetus)...
5 Technical Efficacy: Stage J. Magn. Reson. Imaging 2019;50:677-681.
Abstract Purpose To correct maternal breathing and fetal bulk motion during 4D flow MRI. Methods A Doppler‐ultrasound cardiac‐gated free‐running acquisition was corrected post hoc for respiratory in separate automated steps, with optional manual intervention to assess limit artifacts. Compressed‐sensing reconstruction a data outlier rejection algorithm adapted from previous work. Pre‐ post–motion correction comparison included qualitative visibility of vasculature on phase‐contrast MR...
Background and Aims: Elevated lipoprotein(a) [Lp(a)] familial hypercholesterolemia (FH) are both inherited dyslipidemias that independently associated with cardiovascular disease. Surrogate markers to assess signs of atherosclerosis, such as arterial stiffness, might be useful evaluate the risk in young patients. The aim this study is contribution Lp(a) measured by carotid pulse wave velocity (cPWV) adults FH. Methods: For cross-sectional study, 214 children FH who participated a randomized...
Abstract Purpose Dynamic contrast‐enhanced sequences (e.g. spiral, radial, PROPELLER MRI) often rely on oversampling the center of k‐space. Instead discrete snapshots obtained by Cartesian sampling, k‐space results in time‐averaging signal. We hypothesize that these time‐averaged signals decrease accuracy pharmacokinetic modeling and propose a model accounts for this effect. Theory Methods To test our hypothesis, modified extended Tofts tailored to accommodate is proposed. Simulated Monte...
To image multidimensional flow in fetuses using golden-angle radial phase contrast cardiovascular magnetic resonance (PC-CMR) with motion correction and retrospective gating.
Fetal development relies on a complex circulatory network. Accurate assessment of flow distribution is important for understanding pathologies and potential therapies. In this paper, we demonstrate method volumetric imaging fetal with magnetic resonance (MRI). MRI faces challenges: small vascular structures, unpredictable motion, inadequate traditional cardiac gating methods. Here, orthogonal multislice stacks are acquired accelerated multidimensional radial phase contrast (PC) MRI. Slices...
Background: Recent advances in cardiovascular magnetic resonance (CMR) imaging have facilitated CINE of the fetal heart. In this work, a preliminary investigation utility multislice CMR for assessing congenital heart disease is performed and compared with echocardiography. Methods Results: Multislice echocardiography images were acquired 25 pregnant women wherein fetus had suspected defect based on routine obstetric ultrasound. Pathognomonic identified each subject qualitative comparison...
Evaluation of structural lung abnormalities with magnetic resonance imaging (MRI) has previously been shown to be predictive clinical neonatal outcomes in preterm birth. MRI during free-breathing phase-resolved functional (PREFUL) may allow for complimentary information without exogenous contrast.To investigate the feasibility and pulmonary a cohort neonates infants no cardiorespiratory disease. Macrovascular blood flows were also evaluated.Prospective.Ten term clinically defined disease...
For reliable DCE MRI parameter estimation, k-space undersampling is essential to meet resolution, coverage, and signal-to-noise requirements. Pseudo-spiral (PS) sampling achieves this by on a Cartesian grid following spiral trajectory. The goal was optimize PS patterns for abdomin al MRI.
Crohn’s Disease (CD) is a chronic inflammatory bowel disease. Mesentery of afflicted loops often involved. MR-Elastography allows assessment its underlying mechanical properties and gives more insight in the role mesentery. Feasibility was first shown 15 healthy volunteers. Seven patients with active CD (aCD) scheduled for surgical intervention underwent pre-operative acquisition histopathological analysis. age- sex matched volunteers were also scanned. Significantly higher shear wave speed,...
Background To demonstrate a novel velocity sensitive acquisition and retrospective cardiorespiratory double-gated reconstruction scheme to examine respiratory effect on venous blood flow in healthy volunteers. Methods Radial two dimensional (2D) phase contrast MR is performed at 3 Tesla the internal jugular vein (IJV) of volunteers (n = 6). Data are retrospectively partitioned based waveforms using three schemes: moving average for respiration plateaus, gradient active respiration, ten...
<h3>BACKGROUND AND PURPOSE:</h3> The chronic cerebrospinal venous insufficiency hypothesis raises interest in blood flow imaging, which is more complex and less established than arteries. For accurate assessment of diagnosis research, we must account for physiologic changes patterns. This study examines day-to-day variability veins by use 4D MR contrast-enhanced MRA under typical, uncontrolled conditions healthy individuals. <h3>MATERIALS METHODS:</h3> Ten volunteers were scanned a...
The structure of the valve leaflets and sinuses are crucial in supporting proper function semilunar ensuring leaflet durability. Therefore, an enhanced understanding structural characteristics valves is fundamental to evaluation staging pathology, as well development prosthetic or bioprosthetic valves. This paper illustrates process combining computer-aided design (CAD), 3D printing flow assessment with 4-dimensional magnetic resonance imaging (MRI) provide detailed hemodynamic normal...
Purpose To test and implement a motion‐robust respiratory‐resolved 3D Radial Flow framework that addresses the need for rapid, high resolution imaging in neonatal patients with congenital heart disease. Methods A 4‐point velocity encoding radial trajectory double‐golden angle ordering was combined bulk motion correction (from projection center of mass) respiration phase detection principal component analysis heartbeat‐averaged data) to create cardiac time‐averaged data. This tested...
Key points The ductus venosus (DV) is a dynamic fetal shunt that allows substrate‐rich blood from the umbilical vein to bypass hepatic circulation. In vitro studies suggest direct role of prostaglandin I 2 (PGI ) in regulation DV tone; however, extent this has not been determined utero . 4D flow and T oximetry magnetic resonance imaging can be combined determine oxygen delivery within PGI increases shunting but does increase cerebral delivery. Abstract During development, maintenance...
Background Phase contrast MRI in the great vessels is a potential clinical tool for managing fetal pathologies. One challenge uncontrollable motion, potentially corrupting flow quantifications. Purpose To demonstrate improvements blood quantification using retrospectively motion‐corrected golden‐angle radial phase relative to Cartesian MRI. Study Type Method comparison. Phantom/Subjects Computer simulation. Seventeen pregnant volunteers. Field Strength/Sequence 1.5T and 3T . Assessment...