Overview of MR imaging modalities

Practical approaches to optimization of the use of gadolinium in MR imaging comprise a range of advances in data-acquisition techniques and pulse sequences that augment tissue contrast and reduce scanning times, increasing throughput and patient comfort. In addition to the effects of magnetic field strengths and manipulation of contrast doses for routine spin-echo (SE) imaging, several approaches are reviewed. These include: fat suppression, which helps to resolve enhancing lesions from tissues with inherently high signal on post-gadolinium T1-weighted imaging; gradient-echo (GRE) and partial radio-frequency (RF) echoplanar techniques, which tend to reduce data acquisition times; MR angiography, which enables elucidation of slow-flow vessels and mass-vessel relationships; and three-dimensional GRE scan displays, which relate lesion location to regional and surface anatomy.