BACKGROUND The aim of this study was the evaluation of a fast Gradient Spin Echo Technique (GraSE) for cardiac T2-mapping, combining a robust estimation of T2 relaxation times with short acquisition times. The sequence was compared against two previously introduced T2-mapping techniques in a phantom and in vivo. METHODS Phantom experiments were performed at 1.5 T using a commercially availabl...

A magnetic resonance image (MRI)-based method to determine the colonic transit time is described. It is based on the oral ingestion of a single dose of 4 ml Gd-DOTA following an overnight fast and the subsequent acquisition of fast three-dimensional (3D) gradient-echo sequences under apnea conditions. The technique was successfully evaluated in three healthy volunteers. Transit of the contrast ...

The safety of metallic spinal implants in magnetic resonance imaging (MRI) performed using ultrahigh fields has not been established. Hence, we examined whether the displacement forces caused by a static magnetic field and the heating induced by radiofrequency radiation are substantial for spinal implants in a 7 T field. We investigated spinal rods of various lengths and materials, a screw, and...

The relationship between the apparent diffusion coefficient of tissue water measured by MR methods and the physiological status of cells is of particular relevance for better understanding and interpretation of diffusion-weighted MRI. In addition, there is considerable interest in developing diffusion-dependent imaging methods capable of providing novel information on tissue microstructure, inc...

Background Quantitative myocardial T1 mapping and extracellular volume fraction (ECV) show promise for non-invasive assessment of cardiomyopathies. Most available T1 mapping sequences use a single slice breath-hold acquisition with balanced steady state free precession (b-SSFP) readout [1]. However, b-SSFP readout is sensitive to B0 field inhomogeneity and is potentially T2 dependent [1]. In th...

STUDY DESIGN An in vitro study of the intervertebral disc (IVD) structure using 9.4T magnetic resonance imaging (MRI). OBJECTIVE Investigate the potential of ultrahigh-field strength MRI for higher quality 3-dimensional (3D) volumetric MRI datasets of the IVD to better distinguish structural details. SUMMARY OF BACKGROUND DATA MRI has the advantages of being nondestructive and 3D in compari...

Imaging with spoiled, balanced or nonbalanced gradient echo (GRE) refers to a class of fast imaging sequences that use a dynamic equilibrium or steady state signal for imaging. As originally introduced in 1958 by Carr (1) for NMR spectroscopy, a dynamic equilibrium or steadystate can be established by a train of radio-frequency (RF) excitation pulses interleaved by periods of ‘free precession’,...

We describe MR imaging findings applying gradient echo (GRE) T2*-weighted and fluid-attenuated inversion recovery (FLAIR) MR images at 3T to three patients with hyperacute subarachnoid and intraventricular hemorrhage from ruptured aneurysms. Hyperacute subarachnoid and intraventricular hemorrhages (SAH and IVH) were more clearly visualized as an area of decreased signal intensity on GRE T2*-wei...