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Updated: Mar 15, 2026
Standardized Data Acquisition for Neuromelanin-Sensitive Magnetic Resonance Imaging of the Substantia Nigra
Published on: September 8, 2021
A longitudinal study of neuromelanin-sensitive magnetic resonance imaging in Parkinson's disease
Keita Matsuura1, Masayuki Maeda2, Ken-Ichi Tabei3
1Department of Neurology, Graduate School of Medicine, Mie University, Mie 514-8507, Japan; Department of Neurology, Suzuka Kaisei Hospital, Mie 513-8505, Japan.
Purpose:
Neuromelanin-sensitive MR imaging (NMI) is an increasingly powerful tool for the diagnosis of Parkinson's disease (PD). This study was undertaken to evaluate longitudinal changes on NMI in PD patients.
Methods:
We examined longitudinal changes on NMI in 14 PD patients. The area and contrast ratio (CR) of the substantia nigra pars compacta (SNc) were comparatively analyzed.
Results:
The total area and CR of the SNc upon follow-up NMI were significantly smaller than those on initial NMI (from 33.5±18.9 pixels and 6.35±2.86% to 21.5±16.7 pixels and 4.19±2.11%; Wilcoxon signed-rank test, p<0.001 and p=0.022, respectively). The area and CR of the dominant side SNc upon initial NMI were significantly greater than those on follow-up NMI (from 15.3±9.1 pixels and 6.5±2.7% to 7.9±8.5 pixels and 3.7±2.9%; Wilcoxon signed-rank test, p=0.002 and p=0.007, respectively). On a case-by-case basis, the area of the SNc invariably decreased upon follow-up NMI in all patients. We further demonstrated that the total area and CR of the SNc negatively correlated with disease duration (Pearson correlation coefficient, r=-0.63, p<0.001 and r=-0.41, p=0.031, respectively). In area analyses, our results demonstrated very high intraclass correlation coefficients for both intra- and inter-rater reliability.
Conclusion:
NMI is a useful and reliable tool for detecting neuropathological changes over time in PD patients.
Insights
Neuromelanin-sensitive MR imaging (NMI) shows significant longitudinal decreases in substantia nigra pars compacta (SNc) area and contrast ratio in Parkinson
Area of Science:
- Neuroimaging
- Neurology
- Radiology
Background:
- Neuromelanin-sensitive MR imaging (NMI) is a valuable diagnostic tool for Parkinson's disease (PD).
- Longitudinal assessment of neuropathological changes in PD is crucial for understanding disease progression.
Purpose of the Study:
- To evaluate longitudinal changes in the substantia nigra pars compacta (SNc) using NMI in Parkinson's disease patients.
- To assess the reliability of NMI in tracking PD-related neurodegeneration over time.
Main Methods:
- Longitudinal NMI scans were performed on 14 PD patients.
- Area and contrast ratio (CR) of the SNc were quantitatively analyzed.
- Statistical analyses included Wilcoxon signed-rank test and Pearson correlation.
Main Results:
- Significant reductions in total SNc area and CR were observed over time.
- The dominant side SNc also showed significant decreases in area and CR.
- SNc area and CR negatively correlated with disease duration, indicating progressive loss.
- High intra- and inter-rater reliability was demonstrated for area measurements.
Conclusions:
- NMI is a reliable and effective tool for monitoring longitudinal neuropathological changes in the SNc of PD patients.
- The observed decreases in SNc size and contrast reflect disease progression.
