Nuclear magnetic resonance imaging in evaluation of clinical stroke syndromes

Abstract

Proton nuclear magnetic resonance (NMR) imaging was performed on normal volunteers and patients with various types of clinical strokes. True three‐dimensional volumetric data were obtained for subsequent reconstruction of images at various orientations, including transverse, coronal, and sagittal, and for specific matching to x‐ray computed tomographic planes. A variety of radiofrequency pulse sequences was used to generate images weighted by the NMR parameters spin density (ρ) and spin‐lattice (T1) and spin‐spin (T2) relaxation times. Quantitative T1 data and qualitative T2 information were obtained from appropriate sequences. Proton NMR images embodying T1 information provided adequate delineation of normal intracranial anatomical structure and a high level of gray matter–white matter contrast; high lesion detection sensitivity in various clinical forms of stroke was seen in images providing both T1 and T2 information. T1 and T2 relaxation times were prolonged in embolic, thrombotic, and watershed infarctions as well as in lacunae; shortening of T1 and T2 was found in hematomas. Serpiginous vessels in an arteriovenous malformation were seen that had particular pulse sequences.