Usefulness of diffusion-tensor MRI in the diagnosis of Parkinson variant of multiple system atrophy and Parkinson's disease: a valuable tool to differentiate between them?

AIM: To evaluate the differences between patients with Parkinson's disease (PD) and Parkinson variant of multiple system atrophy (MSAp) at fractional anisotropy (FA) in the white matter when using the tract-based spatial statistics (TBSS) algorithm to provide objective markers for a differential diagnosis. MATERIALS AND METHODS: Diffusion-tensor imaging (DTI) data were acquired from 18 PD patients, 20 MSAp patients, and 24 healthy controls using a GE 3 T Signa HDx magnetic resonance imaging (MRI) system. The hypothesis-free whole-brain analysis (TBSS), focusing on global white matter microstructural deterioration, was adopted based on comparison among groups. Furthermore, regions of interest (ROIs) were drawn on the major fibre bundles showing abnormalities in TBSS. RESULTS: In the MSAp group, FA values significantly decreased in the middle cerebellar peduncle (MCP), pontine crossing tract, and corticospinal tract bilaterally. In the PD group, FA values significantly decreased in multiple supratentorial areas including the corpus callosum (CC), fornix, and left hippocampus. CONCLUSION: DTI may be an effective tool to discover pathological differences between MSAp and PD. To substantially assist the non-invasive differential diagnosis of MSAp and PD, FA measurements should not only be limited to the MCP but also the CC. (C) 2017 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.