Multiparametric quantitative MRI uncovers putamen microstructural changes in Parkinson's disease

Area of Science:

• Neuroscience
• Medical Imaging

Background:

• Parkinson's disease (PD) is a progressive neurodegenerative disorder affecting motor and non-motor functions.
• In vivo characterization of brain microstructure in PD is challenging, hindering diagnostic and therapeutic progress.
• The putamen, critical for movement, is significantly impacted in early PD.

Purpose of the Study:

• To investigate biophysical alterations in the putamen using multiparametric quantitative MRI (qMRI) in PD patients and healthy controls.
• To analyze spatial variations and interhemispheric asymmetries in putamen microstructure along its anterior-posterior axis.

Main Methods:

• Acquisition of multiparametric qMRI data (R1, R2, R2*, WF, susceptibility, MTsat, MD, FA) from PD patients and controls.
• Application of gradient analysis to assess biophysical properties along the anterior-posterior axis of the putamen.
• Correlation analysis between qMRI findings and motor symptom laterality.

Main Results:

• Significant spatial variation and interhemispheric asymmetries in putamen biophysical properties were observed.
• PD patients exhibited altered gradients, notably increased water fraction (WF) in the posterior putamen.
• Increased WF in the posterior putamen correlated with motor symptom laterality in PD patients.

Conclusions:

• The posterior putamen is identified as a hotspot for PD pathology.
• qMRI gradient analysis is a promising tool for detecting clinically relevant microstructural brain changes in PD.
• Altered WF in the posterior putamen may indicate tissue atrophy or neuroinflammation in Parkinson's disease.