We acquired MRI data on a 3T Siemens Skyra MRI scanner (Siemens, Erlangen, Germany) equipped with a 32-channel head coil and the Syngo MR D13 software version, located at Singapore General Hospital between September 2014 and 2021. The MRI scan included a DKI sequence with the following parameters: TE = 102 ms, TR = 10.118 s, FA = 90°, in-plane voxel size = 1.8×1.8 mm, slice thickness = 2.5 mm, matrix = 112×112, 55 contiguous slices, anterior-posterior phase encoding, 60 diffusion-weighted volumes (30 at b = 1000 mm/s2 and 30 at 2000 mm/s2) evenly distributed on the unit sphere and 3 volumes with b = 0 mm/s2. It also included a sagittal T1-weighted MPRAGE sequence with the following parameters: TE = 0.002 s, TR = 1.9 s, FA = 9°, in-plane voxel size = 1×1 mm, slice thickness = 1 mm, matrix = 256×256, 256 contiguous slices. No changes to the scanner software or hardware were made during the course of the study.
Clinical assessments included the Movement Disorder Society Unified Parkinson’s Disease Rating Scale Part III (MDS-UPDRS-III; [24 (link)]), Hoehn & Yahr stage [25 (link)] and Montreal Cognitive Assessment (MoCA) [26 (link)], and were obtained by a neurologist during the same visit as the MRI. Patients’ Levodopa equivalent daily dose (LEDD) was recorded. All data were gathered during the “on” medication state.
Clinical assessments included the Movement Disorder Society Unified Parkinson’s Disease Rating Scale Part III (MDS-UPDRS-III; [24 (link)]), Hoehn & Yahr stage [25 (link)] and Montreal Cognitive Assessment (MoCA) [26 (link)], and were obtained by a neurologist during the same visit as the MRI. Patients’ Levodopa equivalent daily dose (LEDD) was recorded. All data were gathered during the “on” medication state.