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Updated: Nov 30, 2025
Diffusion Tensor Magnetic Resonance Imaging in the Analysis of Neurodegenerative Diseases
Published on: July 28, 2013
Mean Apparent Propagator MRI Is Better Than Conventional Diffusion Tensor Imaging for the Evaluation of Parkinson's
Hongbo Le1,2, Weike Zeng2, Huihong Zhang3
1Department of Radiology, The Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai, China.
Background And Purpose:
Mean apparent propagator (MAP) MRI is a novel diffusion imaging method to map tissue microstructure. The purpose of this study was to evaluate the diagnostic value of the MAP MRI in Parkinson's disease (PD) in comparison with conventional diffusion tensor imaging (DTI).
Methods:
23 PD patients and 22 age- and gender-matched healthy controls were included. MAP MRI and DTI were performed on a 3T MR scanner with a 20-channel head coil. The MAP metrics including mean square displacement (MSD), return to the origin probability (RTOP), return to the axis probability (RTAP), and return to the plane probability (RTPP), and DTI metrics including fractional anisotropy (FA), and mean diffusivity (MD), were measured in subcortical gray matter and compared between the two groups. The receiver operating characteristic (ROC) curve was used to analyze the diagnostic performance of all the metrics. The association between the diffusion metrics and disease severity was assessed by Pearson correlation analysis.
Results:
For MAP MRI, the mean values of MSD in the bilateral caudate, pallidum, putamen, thalamus and substantia nigra (SN) were higher in PD patients than in healthy controls (p FDR ≤ 0.001); the mean values of the zero displacement probabilities (RTOP, RTAP, and RTPP) in the bilateral caudate, pallidum, putamen and thalamus were lower in PD patients (p FDR < 0.001). For DTI, only FA in the bilateral SN was significantly higher in PD patients than those in the controls (p FDR < 0.001). ROC analysis showed that the areas under the curves of MAP MRI metrics (MSD, RTOP, RTAP, and RTPP) in the bilateral caudate, pallidum, putamen and thalamus (range, 0.85-0.94) were greater than those of FA and MD of DTI (range, 0.55-0.69) in discriminating between PD patients and healthy controls. RTAP in the ipsilateral pallidum (r = -0.56, p FDR = 0.027), RTOP in the bilateral and contralateral putamen (r = -0.58, p FDR = 0.019; r = -0.57, p FDR = 0.024) were negatively correlated with UPDRS III motor scores.
Conclusion:
MAP MRI outperformed the conventional DTI in the diagnosis of PD and evaluation of the disease severity.
Insights
Mean apparent propagator (MAP) MRI shows superior diagnostic value for Parkinson's disease (PD) compared to diffusion tensor imaging (DTI). MAP MRI metrics effectively differentiate PD patients and correlate with disease severity.
Area of Science:
- Neuroimaging
- Biomedical Engineering
- Radiology
Background:
- Parkinson's disease (PD) is a neurodegenerative disorder affecting motor function.
- Accurate diagnostic tools are crucial for early detection and management of PD.
- Conventional diffusion tensor imaging (DTI) has limitations in characterizing microstructural changes in PD.
Purpose of the Study:
- To evaluate the diagnostic performance of Mean Apparent Propagator (MAP) MRI in Parkinson's disease.
- To compare the efficacy of MAP MRI with conventional diffusion tensor imaging (DTI) for PD diagnosis.
- To assess the correlation between diffusion metrics and PD severity.
Main Methods:
- 23 PD patients and 22 healthy controls underwent MAP MRI and DTI on a 3T scanner.
- MAP metrics (MSD, RTOP, RTAP, RTPP) and DTI metrics (FA, MD) were measured in subcortical gray matter.
- Receiver operating characteristic (ROC) curve analysis and Pearson correlation were used.
Main Results:
- MAP MRI metrics showed significant differences between PD patients and controls in multiple subcortical regions.
- DTI revealed significant differences only in FA of the substantia nigra (SN).
- MAP MRI metrics demonstrated higher accuracy (AUC 0.85-0.94) than DTI metrics (AUC 0.55-0.69) in discriminating PD.
- Specific MAP metrics correlated negatively with UPDRS III motor scores.
Conclusions:
- MAP MRI is a more effective imaging technique than DTI for diagnosing Parkinson's disease.
- MAP MRI provides valuable insights into microstructural alterations in PD.
- MAP MRI metrics can aid in evaluating PD disease severity.
