Deep-learning saturation transfer magnetic resonance fingerprinting (ST-MRF) in patients with Parkinson's disease.

Parkinson's disease (PD) is marked by progressive neurodegeneration in the substantia nigra (SN). This study evaluated deep-learning saturation-transfer magnetic resonance fingerprinting (ST-MRF) to quantify molecular and microstructural changes in PD. We examined 23 patients with PD (PwPD) and 22 matched healthy controls (HCs) using multimodal imaging, including ST-MRF. ST-MRF detected significant molecular and microstructural alterations in the SN of PwPD compared to HCs, including increases in magnetization transfer ratio at 3.5 ppm (MTR(3.5ppm, 1.5 µT); 0.612 ± 0.022 vs. 0.597 ± 0.021, p = 0.014), MTR(-3.5ppm, 1.5 µT); 0.614 ± 0.021 vs. 0.586 ± 0.019, p = 0.008)), and decreases in T2w (51.9 ± 3.4 vs. 54.5 ± 1.3 ms, p = 0.005), suggesting disrupted protein homeostasis and iron accumulation. ST-MRF provides multiparametric insights into PD-related pathology and may serve as a candidate tool for future biomarker studies. Validation in larger, longitudinal cohorts will be essential to establish its clinical utility.