OVERVIEW OF MR-IMAGING MODALITIES

Practical approaches to optimization of the use of gadolinium in MR im aging 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 effect s of magnetic field strengths and manipulation of contrast doses for r outine spin-echo (SE) imaging, several approaches are reviewed. These include: fat suppression, which helps to resolve enhancing lesions fro m tissues with inherently high signal on postgadolinium T1-weighted im aging; gradient-echo (GRE) and partial radio-frequency (RF) echoplanar techniques, which tend to reduce data acquisition times; MR angiograp hy, which enables elucidation of slow-flow vessels and mass-vessel rel ationships; and three-dimensional GRE scan displays, which relate lesi on location to regional and surface anatomy.