[High-field-strength magnetic resonance imaging and SPECT of multiple system atrophy].

Two cases of multiple system atrophy (MSA) showing similar abnormalities by magnetic resonance (MR) imaging and SPECT are reported. The clinical diagnoses of the two cases were striatonigral degeneration (SND) and sporadic olivopontocerebellar atrophy (OPCA). In addition, one case of sporadic OPCA without parkinsonism was used for comparison. The MR images were obtained using a 1.5-T MR system and included spin-echo transverse sections with T1-weighted images (TR = 450 ms and TE = 15 ms) and T2-weighted images (TR = 2500 ms and TE = 90 ms). The T1-weighted images demonstrated atrophy of cerebellum and pons, with increased signal intensity in the bilateral putamen. The T2-weighted images demonstrated decreased signal intensity in the putamen, as reported recently. SPECT demonstrated reduced uptake in the celleberum, basal ganglia and frontal lobe cortex. The putaminal changes evident on T1-weighted images may have resulted from deposition of pigments such as neuromelanin and lipofuscin, related to parkinsonism. Both T1- and T2-weighted MRI seem to be useful clinical diagnosis of MSA.