Diagnosis of patients with Parkinson's disease using quantitative susceptibility mapping

Introduction: Parkinson'sdisease isassociated withirondeposition in the brain. The T2-weighted imaging, T2* mapping, R2 mapping and Quantitative Susceptibility Mapping (QSM) are three common methods to evaluating the iron deposition in brain. Among three methods the QSM is more sensitive than others. Few studies have been used QSM for evaluating the iron deposition in the basal ganglia of patients with Parkinson's Disease (PD). Therefore, our aim was to evaluate the amount of iron deposition in the basal ganglia using QSM and determination the diagnostic value of this method; Also we evaluated the relationship between the QSM with age and stage of the disease. Materials and Methods: Thirty patients categorized in three different stages using Hoehn and Yahr tests. The number of 8, 11 and 11 patients were considered for stage 1, stage 2 and stage 3, respectively. Fifteen healthy subjects were considered as control group. MRI sequences were performed using SIEMENS 3T scanner. The SPIN (Signal Processing in NMR) software was used to processing and analyzing the images. The QSM was measured in all basal ganglia (Red Nucleus, Substantia Nigra, Caudate, Globus Pallidus, Putamen, and Thalamus) separately. The SPSS 18 (SPSS Inc., Chicago, IL) used for analyzing the data. Results: There was a significant difference (P-value<0.001) for QSM in the Red Nucleus, Substantia Nigra and Globus Pallidus nuclei between two patient and control group. The relationship between disease stage with QSM was significant in Red Nucleus (RN), Substantia Nigra (SN) and Globus Pallidus (GP) nuclei (P-value<0.001). Correlation of QSM with age was not significant in any of the nuclei. The accuracy of QSM was 98.0, 86.7 and 88.9 percent for SN, RN and GP. The specificity of QSM was 93.3, 100.0 and 86.7% for SN, RN and GP; Also the sensitivity was 100.0, 80.0 and 90.0 for SN, RN and GP, respectively. Conclusion: Using QSM in RN, SN, and GP nuclei can help diagnosis and staging of patients with Parkinson's disease. Future studies with emphasis on the disease stage using larger sample size can be helpful in evaluation the different sub-parts of these nuclei.