Evaluation of Hemodynamic and Blood Oxygen Metabolism Alterations in Parkinson's Disease Using Quantitative MRI

To investigate hemodynamic and blood oxygen metabolism and their associations with disease progression, dopaminergic transporter (DAT) activity, and glucose uptake in patients with Parkinson's disease (PD).

This cross-sectional study included 73 patients with PD (mean age: 61.10 years) and 67 healthy controls (mean age: 58.99 years). Oxygen metabolism parameters-deoxygenated hemoglobin (Cdeoxy), oxygen extraction fraction (OEFrel), deoxygenated cerebral blood volume (dCBV), and R2* were measured using qMRI. DAT availability and glucose metabolism were assessed using PET with [18F]FP-CIT and [18F]FDG, respectively. Regional analyses were conducted using standardized brain atlases.

Compared with the controls patients with PD exhibited elevated Cdeoxy, OEFrel, and R2* in the substantia nigra, whereas Cdeoxy and dCBV levels were reduced in the bilateral caudate nucleus and frontal cortex (p < 0.05). The Hoehn-Yahr (H-Y) 2.5-3 subgroup exhibited higher levels of Cdeoxy and OEFrel in the left putamen than the H-Y 1-2 subgroup (p < 0.05). In the H-Y 1-2 subgroup, Cdeoxy, OEFrel, and R2* correlated with UPDRS scores in the substantia nigra and red nucleus (p < 0.05). In advanced stages (H-Y stages 2.5-3), significant correlations were observed in the striatal structures/the left dorsolateral putamen/posterior right caudate (p < 0.05). OEFrel and R2* values were positively correlated with glucose metabolism in the left putamen and right caudate. (p < 0.05).

qMRI demonstrated alterations in hemodynamics and oxygen metabolism in patients with PD, particularly within the nigrostriatal system, suggesting that metabolic indicators could serve as supplementary biomarkers for diagnosing and monitoring the progression of PD.