Mapping Neurodegenerative Changes in Clinically Uncertain Parkinsonian Syndrome Patients Using Fast <scp>MR</scp> Spin <scp>TomogrAphy</scp> in Time‐Domain ( <scp>MR</scp> ‐ <scp>STAT</scp> ) Relaxometry at 3T

BACKGROUND: ). Previous relaxometry studies predominantly compared Parkinson's disease patients with healthy controls (HC). The potential of relaxometry to distinguish neurodegenerative from non-neurodegenerative parkinsonism in clinically uncertain parkinsonian syndrome (CUPS) patients is unclear. PURPOSE: -differences between neurodegenerative and non-neurodegenerative parkinsonism in CUPS patients. STUDY TYPE: Prospective cross-sectional study. POPULATION: 52 patients with neurodegenerative and 57 patients with non-neurodegenerative parkinsonism, diagnosed via dopamine transporter single photon emission computed tomography (DAT SPECT) and neurologist review, and 10 HC. FIELDSTRENGTH/SEQUENCE: MP-RAGE (magnetization-prepared rapid acquisition with gradient-echoes) and MR-STAT, a 2D Cartesian-encoded gradient-spoiled gradient-echo sequence with time-varying flip-angle preceded by a non-selective inversion pulse, at 3T. ASSESSMENT: -values of the parkinsonism groups were compared in the same regions per most/less affected hemisphere (MAH/LAH), determined by the putaminal uptake ratio on DAT SPECT. STATISTICAL TESTS: -values between parkinsonism groups, and Cohen's D values were computed with bootstrapping to measure effect sizes with 95% confidence intervals (95% CI). RESULTS: -differences were non-significant. DATA CONCLUSION: MR-STAT showed high repeatability and showed potential to differentiate neurodegenerative from non-neurodegenerative parkinsonism in CUPS patients. EVIDENCE LEVEL: 1. TECHNICAL EFFICACY: 1.