AbstractIntroduction: Recent evidence is shedding insights into the functional alterations in the sensorimotor, visual and basal ganglia networks in Parkinson’s Disease (PD) patients. We evaluated the Functional Anisotropy (FA) and Apparent Diffusion Coefficient (ADC) values in PD patients with DTI using Region of Interest (ROI) basis and compare it with healthy controls. Methodology: A case control study was conducted comprising of 40 PD patients, and similar healthy controls. They were evaluated using 1.5 tesla MRI Machine and DTI were performed using a single-shot sequence with diffusion encoding in 31 directions. In each subject, four deep grey matter structures (Caudate nucleus, putamen, pallidum and substantia nigra) were segmented. Differences in FA and ADC between groups were assessed using t-test to compare means. Results: Mean FA values of PD cases when compared with control cases were significantly less on both sides. Mean ADC values of PD cases were significantly higher as compared to controls at caudate nucleus and substantia nigra on both sides. Mean ADC values for lentiform nucleus were not significantly different between PD cases and controls on both sides. ROC analysis found the cut off value of FA and ADC to be 0.26 and 8.05 at caudate nucleus, 0.26 and 7.5 at lentiform nucleus and 0.46 and 8.2 at substantia nigra respectively. Conclusions: Advanced image analysis is derived from improved image algorithms, which can help in automated differentiation of PD and related disorders. DTI is a promising tool to assess PD-related neurodegeneration and potentially could serve as marker for PD.
Keywords: Parkinson’s disease; Diffusion weighted imaging; Magnetic resonance imaging; Fractional anisotropy.