Comparative Study Of Brain Iron Metabolism In Multiple Sclerosis And Neuromyelitis Optica Spectrum Disorder Patients By MRI

PART ONE IRON DEPOSITION IN THE POSTCENTRAL GYRUS BY ESWAN BETWEEN PATIENTS WITH RRMS AND PATIENTS WITH NMOSD:A COMPARATIVE STUDYObjective:To measure and compare iron deposition in the postcentral gyrus using three-dimensional enhanced T2~*weighted angiography(ESWAN)between patients with relapsing-remitting multiple sclerosis(RRMS)and patients with neuromyelitis optica spectrum disorder(NMOSD)and to evaluate its correlation with acroparesthesia.Materials and Methods:A total of 30 patients with RRMS,21 patients with NMOSD,and 30healthy controls(HC)underwent ESWAN scanning.Mean phase values(MPVs)in the postcentral gyrus were measured on the ESWAN-flitered phase(phase).The Kruskal-Wallis test was used to compare the MPVs differences among the three groups.The Spearman correlation analysis was used to evaluate correlations between the MPVs and Fugl-meyer sensory score(FmSS)and disease duration,respectively.Results:(1)The MPVs of the postcentral gyrus in the patients with RRMS were lower than that in the patients with NMOSD(t=-18.94,P﹤0.05)and HC(t=-26.43,P<0.01).The MPVs in the postcentral gyrus in patients with NMOSD had a lower trend than that in HC,but there was no statistically significant difference(t=-7.50,P>0.05).(2)The MPVs of postcentral gyrus were positively correlated with the FmSS in both patients with RRMS and patients with NMOSD(r=0.390and r=0.446,respectively;P<0.05),but no correlation was found between the MPVs and disease duration(P>0.05).Conclusion:Abnormal iron deposition in the postcentral gyrus in the patients with RRMS is much more serious than that in the patients with NMOSD.The iron contents are related to the FmSS in both patients with RRMS and patients with NMOSD,serving as a good marker for disease monitoring and curative evaluation in these two diseases.PART TWO CONTRASTIVE ANALYSIS OF IRON DEPOSITION IN RRMS VS NMOSD LESIONS BY PHASEObjective:To observe and compare the characteristics and differences of MRI phase changes in relapsing-remitting multiple sclerosis(RRMS)versus neuromyelitis optica spectrum disorder(NMOSD)lesions by using three-dimensional enhanced T2* weighted angiography filtered phase(phase).Materials and Methods:54 patients with RRMS and 49 patients with NMOSD underwent 3T brain scanning including proton density/T2-weighted imaging(PD/T2)and ESWAN.Lesions were uniformly defined as abnormal hyperintensity on PD/T2 and then were analyzed on the phase images one by one with respect to paramagnetic phase changes.The c2 test was used to compare the differences of nodular and rim phase changes between the two groups;receiver operating characteristic curve(ROC)analysis were performed to calculate the area under the curve(AUC)for distinguishing RRMS and NMOSD on the basis of the presence of nodular and rim phase changes.Results:(1)A total of 968 MS lesions in 54/54(100%)patients with RRMS and 247 NMOSD lesions in 41/49(84%)patients with NMOSD were detected.(2)Nodular(373/968,39%)and rim-like(198/968,20%)phase changes were exclusively seen in MS lesions,while almost(nodular: 5/247,2%,P < 0.001;rim-like: 0/247,0%,P < 0.001)invisible in NMOSD lesions.(3)The percent of lesions with central veins(CV)was significant higher in MS(354/968,36%)lesions than that of NMOSD(4/247,2%,P<0.001)lesions.(4)The area under the curve(AUC)for nodular phase changes distinguishing RRMS from NMOSD was 0.922 with a sensitivity of 92.6%and a specificity of 91.8%;the corresponding AUC,sensitivity,specificity for rim phase changes were 0.861,72.2%,100%,respectively.Conclusion:Nodular and rim-like phase changes are characteristics for MS lesions,but rarely seen in NMOSD lesions,which can help in understanding the distinct iron metabolism mechanisms between RRMS and NMOSD and provide another imaging feature for the differential diagnosis.