Fast 3 T nigral hyperintensity magnetic resonance imaging in Parkinson's disease

Area of Science:

• Neurology
• Radiology
• Medical Imaging

Background:

• Nigral hyperintensity on MRI is a potential biomarker for Parkinson's disease (PD).
• The small size of the substantia nigra limits routine imaging of this marker.
• Current MRI sequences face challenges with motion sensitivity and diagnostic confidence.

Purpose of the Study:

• To compare the efficacy of various MRI sequences for imaging nigral hyperintensity in PD.
• To evaluate sensitivity to motion, radiologist confidence, non-diagnostic scan rates, and diagnostic accuracy.
• To identify the optimal MRI technique for clinical application in PD diagnosis.

Main Methods:

• Comparison of Multi Echo Data Image Combination (MEDIC), segmented echo-planar imaging (EPISEG), fluid-attenuated inversion recovery (FLAIR), and single-echo gradient echo (magnitude and SWI reconstructions).
• Assessment of motion sensitivity, radiologist confidence, non-diagnostic scan rates, and diagnostic accuracy in 25 healthy and 20 PD subjects.
• Correlation of nigral hyperintensity findings with clinical PD severity scales (Hoehn-Yahr, MDS-UPDRS).

Main Results:

• EPISEG demonstrated superior motion sensitivity and higher radiologist confidence compared to MEDIC, FLAIR, MAG, and SWI.
• EPISEG yielded the lowest proportion of non-diagnostic scans.
• EPISEG achieved the highest diagnostic performance (sensitivity 65%, specificity 96%) for detecting nigral hyperintensity.
• Absence of nigral hyperintensity correlated with advanced PD stages.

Conclusions:

• Segmented echo-planar imaging (EPISEG) is a highly effective MRI technique for visualizing nigral hyperintensity in Parkinson's disease.
• EPISEG's robustness against motion artifacts and high diagnostic accuracy make it suitable for routine clinical practice.
• Nigral hyperintensity may be preserved in early PD stages, suggesting its absence could indicate more advanced disease.