Oliver E Wieben

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A wide variety of fat suppression and water-fat separation methods are used to suppress fat signal and improve visualization of abnormalities. This article reviews the most commonly used techniques for fat suppression and fat-water imaging including 1) chemically selective fat suppression pulses "FAT-SAT"; 2) spatial-spectral pulses (water excitation); 3)(More)
Traditionally, magnetic resonance imaging (MRI) of flow using phase contrast (PC) methods is accomplished using methods that resolve single-directional flow in two spatial dimensions (2D) of an individual slice. More recently, three-dimensional (3D) spatial encoding combined with three-directional velocity-encoded phase contrast MRI (here termed 4D flow(More)
Recent work in k-t BLAST and undersampled projection angiography has emphasized the value of using training data sets obtained during the acquisition of a series of images. These techniques have used iterative algorithms guided by the training set information to reconstruct time frames sampled at well below the Nyquist limit. We present here a simple(More)
BACKGROUND AND PURPOSE Arterial wall enhancement on vessel wall MRI was described in intracranial inflammatory arterial disease. We hypothesized that circumferential aneurysmal wall enhancement (CAWE) could be an indirect marker of aneurysmal wall inflammation and, therefore, would be more frequent in unstable (ruptured, symptomatic, or undergoing(More)
BACKGROUND AND PURPOSE Clinical indications of giant cell arteritis may be unspecific, and noninvasive diagnosis is often difficult. This study investigated the hypothesis that high-resolution MR imaging of the superficial cranial arteries is a noninvasive imaging technique that can detect the occurrence of giant cell arteritis. MATERIALS AND METHODS(More)
PURPOSE To implement and validate in vivo radial 4D flow MRI for quantification of blood flow in the hepatic arterial, portal venous, and splanchnic vasculature of healthy volunteers and patients with portal hypertension. MATERIALS AND METHODS Seventeen patients with portal hypertension and seven subjects with no liver disease were included in this Health(More)
Pulsatile blood flow through the cavities of the heart and great vessels is time-varying and multidirectional. Access to all regions, phases and directions of cardiovascular flows has formerly been limited. Four-dimensional (4D) flow cardiovascular magnetic resonance (CMR) has enabled more comprehensive access to such flows, with typical spatial resolution(More)
Cardiac MRI has become a routinely used imaging modality in the diagnosis of cardiovascular disease and is considered the clinically accepted gold standard modality for the assessment of cardiac function and myocardial viability. In recent years, commercially available clinical scanners with a higher magnetic field strength (3.0 T) and dedicated(More)
PURPOSE To estimate surface-based wall shear stress (WSS) and evaluate flow patterns in ascending aortic dilatation (AscAD) using a high-resolution, time-resolved, three-dimensional (3D), three-directional velocity encoded, radially undersampled phase contrast MR sequence (4D PC-MRI). MATERIALS AND METHODS 4D PC-MRI was performed in 11 patients with AscAD(More)
PURPOSE To compare pulmonary artery flow using Cartesian and radially sampled four-dimensional flow-sensitive (4D flow) MRI at two institutions. METHODS Nineteen healthy subjects and 17 pulmonary arterial hypertension (PAH) subjects underwent a Cartesian 4D flow acquisition (institution 1) or a three-dimensional radial acquisition (institution 2). The(More)