The Visibility Of Nuclei In Patients With Parkinson’s Disease Using Susceptibility-weighted Imaging And The Measurement Of Iron Deposition Differences In Those Nuclei

ObjectiveTo evaluate the visibility of the globus pallidus interna (Gpi), subthalamic nucleus(STN) and ventral intermediate nucleus(Vim) using susceptibility-weighted imaging (SWI) for Parkinson’s disease (PD); To measure the differences of iron deposition in those nuclei between the PD group and the control group.Materials and Methods15patients (8male,7female; age range,50～74years; average age,63.67±6.54years) with Parkinson’s disease diagnosed clinically (6static tremor,8limb rigidity,1both limb tremor and limb rigidity; exclusion criteria:PDS caused by trauma, poisons, drugs, cerebrovascular disease or other reasons)and15age-and sex-matched volunteers (8male,7female; age range,52-75years; average age,63.07±7.27years)were examined by MR from June of2012to December of2012. All of them had been scanned with a3.0Tesla MRI system (GE Signa EXCITE HD3.0T, The USA) facilitated by the standard circularly polarized head coil. Imaging sequences included SWI sequences and T,WI-FLAIR, FSE-T2WI, T2WI-FLAIR sequences. According to the uniformity of nucleus, signal contrast, and border sharpness between the Gpi,STN,Vim and surrounding structures, the images were classified into four grades (grade1,2,3,4) by2experienced radiologists. The visibility of the three nuclei was evaluated in the four sequences. And the ROI were selected symmetrically by10mm2. The phase values of those nuclei were respectively measured on corrected phase images. The Independent Sample T Test was used to compare the phase values.ResultsIn SWI sequences, those nuclei in patients with PD were clearly visualized with high uniformity, good signal contrast and border sharpness (2patients were classified into grade4,12patients were classified into grade3,1patient was classified into grade2,0patient was classified into grade1). In T2WI and T2-FLAIR sequences, most of those nuclei in patients with PD showed less uniformity, signal contrast and border sharpness, and couldn’t be identified easily(0patient was classified into grade4,1patient was classified into grade3,11patients were classified into grade2,3patients were classified into grade1;1patient was classified into grade4,1patient was classified into grade3,11patients were classified into grade2,2patients were classified into grade1). In T1WI sequences, most of those nuclei in patients with PD showed poor uniformity, signal contrast and border sharpness, and could hardly be identified(0patient was classified into grade4,0patient was classified into grade3,1patient was classified into grade2,14patients were classified into grade1). Significant differences were found among those four sequences. And there were statistically significant differences in the average phase values between the PD group and the control group in Gpi (t=11.693, P<0.05) and STN (t=6.958, P<0.05), indicating the existence of iron deposition. But no significant difference in ventral intermediate nucleus(t=0.755, P>0.05), indicating no iron deposition.ConclusionCompared to conventional MR sequences, SWI improves the visibility of the Gpi, STN, Vim. And there are different iron deposition changes in different nuclei.