Clinical utility and limitation of MRI in neuroradiology

Magnetic resonance imaging (MRI) has several advantages over computed tomography in the neuroradiological field: it provids biochemical information, images in any plane without bone artifacts, and superior contrast between gray matter and white matter. It is, however, of limited availability because of longer imaging time, poor spatial resolution, and poor visualization of calcification and the bone. In this review, pathophysiology that shows relatively characteristic signal intensity is described, including hemorrhage, fat, protein-rich cyst, calcification, iron, and posterior pituitary gland. The utility and limitation of MRI are discussed in terms of the following diseases and lesion sites: small tumors in the skull base; demyelination of white matter or degenerative disease; cerebral infarction or cerebral ischemic disease; intramedullary lesion; meningeal lesion; and pediatric diseases such as medullary sheath formation and malformation. Finally, recent advance and future perspectives of MRI are presented, focusing on 3-dimensional imaging, MR angiography, fat-suppression MR imaging, MR spectroscopy, intravoxel incoherent motion imaging, imaging time, and spatial resolution. (N.K.) 82 refs