Diffusion weighted imaging best discriminates PD from MSA-P: A comparison with tilt table testing and heart MIBG scintigraphy.

Both diffusion weighted magnetic resonance imaging (DWI) of the basal ganglia and meta-iodobenzylguanidin (MIBG) scintigraphy of the heart have been reported useful in the differential diagnosis of patients with Parkinson's disease (PD) vs. the parkinson variant of multiple system atrophy (MSA-P). Their diagnostic value, however, has never been directly compared in patients with parkinsonism and autonomic dysfunction.