Application value of multiparametric MRI for evaluating iron deposition in the substantia nigra in Parkinson's disease

Abstract

ObjectiveThis study aimed to investigate the application value of multi-parametric magnetic resonance imaging (MRI) in the diagnosis of iron deposition in the substantia nigra dense zone in Parkinson's disease (PD) and to evaluate the diagnostic value of the correlation among multi-parametric imaging indicators, clinical stage, and disease duration.Materials and methodsThirty-six patients with clinically confirmed PD and 36 healthy controls were enrolled. The disease course was recorded, and PD severity was graded using the Hoehn–Yahr (H–Y) scale. All subjects underwent magnetic sensitivity weighted imaging (SWI), neuromelanin magnetic resonance imaging (NM-MRI), and a T2*mapping sequence. Based on the fusion of the NM-MRI and SWI amplitude maps, phase maps, and T2*MAPPING value maps, NM-MRI was used to delineate the dense zone of the substantia nigra, which was divided into three sub-regions: upper, middle, and lower. In this way, the amplitude, phase, and R2* values of each sub-region and the average value of the sum of the three sub-regions were obtained simultaneously in the SWI amplitude, phase, and T2*MAPPING maps. The multi-parameter imaging indices were compared between the two groups, and the correlation between them and clinical indices was evaluated in the PD group.ResultsThe upper (amplitude, phase value, R2* value), middle, and lower (amplitude) right substantia nigra compact zones were significantly different between the PD and control groups. The upper (phase value, R2* value) and middle (amplitude) areas of the left substantia nigra compact zone were also significantly different between the two groups (all P < 0.05). The mean values (amplitude, phase value, R2* value) of the right substantia nigra densification zone and the mean values (phase value) of the left substantia nigra densification zone were also significantly different (all P < 0.05). Amplitudes in the middle and lower parts of the right substantia nigra dense zone were negatively correlated with the H–Y grade (middle: r = −0.475, P = 0.003; lower: r = −0.331, P = 0.049). Amplitudes of the middle and lower parts of the dense zone of the left substantia nigra were negatively correlated with the H–Y grade (middle: r = −0.342, P = 0.041; lower: r = −0.399, P = 0.016). The average amplitude of the right substantia nigra compact zone was negatively correlated with the H–Y grade (r = −0.367, P = 0.027). The average R2* value of the compact zone of the left substantia nigra was positively correlated with the H–Y grade (r = 0.345, P = 0.040).ConclusionMultiparametric MRI sequence examination has application value in the evaluation of iron deposition in the dense zone of the substantia nigra in PD. Combined with NM-MRI, fusion analysis is beneficial for accurately locating the substantia nigra compact zone and quantitatively analyzing the iron deposition in different sub-regions. Quantitative iron deposition in the middle and lower parts of the substantia nigra dense zone may become an imaging biological indicator for early diagnosis, severity evaluation, and follow-up evaluation of PD and is thus conducive for clinical diagnosis and treatment evaluation.

Automatic Segmentation and Quantification of Nigrosome‐1 Neuromelanin and Iron in MRI: A Candidate Biomarker for Parkinson's Disease

“…In comparison with recent, similar studies in terms of diagnostic accuracy, we achieve higher performance values than Cao et al, 38 who performed a manual segmentation of the SNc and quantified iron deposition values through the amplitude and phase of the SWI image and the R2* value, achieving AUC values between 0.538 and 0.678 for these parameters. He et al, 6 on the other hand, obtain an AUC = 0.89 for the N1 sign in iron‐sensitive images.…”

Iron Deposition in Parkinson’s Disease: A Mini-Review

“…It reveals the correlation between iron deposition and the decline in dopamine function and reduced neuromelanin in the SN of PD (Depierreux et al 2021 ). The quantitative evaluation of iron accumulation within the inferior region of the SN pars compacta holds the potential to function as an imaging biomarker for the early diagnosis, severity assessment, and subsequent monitoring of PD (Cao et al 2022 ).…”

The Irony of Iron: The Element with Diverse Influence on Neurodegenerative Diseases

“…In PD, nigral iron accumulation presents as a prominent iron-related disease marker. However, MRI studies examining the changes in SN iron levels throughout disease progression suggest such increase may be more strongly correlated with progression at mid-to-later stages of the disease [122,123,131]. Accordingly, MRI observations of PD nigral iron still report inconsistent results [105,122,126], with even lower levels reported in early stage drug-naïve patients [126], whereas post-mortem examinations consistently report increased iron levels in the SN [102,104,132,133].…”