MRI Multimodality Technique Analysis And Differential Diagnosis In Autoimmune Myositis With Dermatomyositis

Purpose:To explore MRI T2 mapping and RS-EPI sequence of thigh muscles in patients with dermatomyositis(DM).Methods:Nine normal volunteers and twenty-eight patients with DM were enrolled.Thirty-seven participants were evaluated nonquantitative MR imaging and axial T2 mapping and RS-EPI from upper to lower thigh.Twenty-eight patients were evaluated serum CK,the amount of muscle edema and fatty infiltration were assigned a grade of zero to four for all thigh muscles by using T1-weighted and T2-weighted nonquantitative MR images.The Spearman correlation coefficients model was used to correlate the mean T2 and ADC,nonquantitative MR imaging score and clinical assessments.Results: The mean T2 and ADC value of oedematous muscles in the DM group were higher on average and showed a statistically significant difference when compared with unaffected(non-oedematous muscles in patients)and normal muscles(p<0.05),and the mean T2 value were higher and showed a statistically significant difference when compared with normal muscles(p<0.05),while the mean ADC value was no statistical difference between non-oedematous muscles in patients and normal muscles(p>0.05).The mean T2 value with affected muscles in DM patients among zero to seven were statistical differences(p<0.05),while the mean ADC value were no statistical differences(p>0.05).The mean T2 for these muscles showed a significant correlation with the nonquantitative MR imaging score for muscle edema and fatty infiltration,and with the clinical assessments CK level.Conclusion: MR T2 mapping and DWI could objectively evaluate the severity of affected muscles in DM patients.Compared with DWI sequence,T2 mapping sequence could not only reflect inflammatory activity,but also chronic inflammation,including fatty infiltration and muscle necrosis.Purpose:To explore MRI T2 mapping and IVIM-DWI sequence of thigh muscles in patients with DM,NAM and MD?Methods:Thirty-four patients with DM,fourteen patients with NAM and thirteen patients with MD were enrolled and evaluated nonquantitative MR imaging and axial T2 mapping and IVIM-DWI from upper to lower thigh.The mean T2 value,ADC,D,f and D* of thigh muscles were compared among PM,NAM and MD patients by using ANOVA statistical method.Compared the ROC of these parameter for distinguishing DM,NAM and MD patients.Results: The mean T2 value of thigh muscles among the DM,NAM and MD group were statistically significant difference(p<0.05),and the mean T2 value of MD patients were higher and showed a statistically significant difference when compared with DM and NAM patients(p<0.05),while the mean T2 value was no statistical difference between DM and NAM(p>0.05).The mean ADC?D and f value of MR IVIM-DWI DWI parameters among DM,NAM and MD patients were statistical differences(p<0.05),while the mean D* value were no statistical differences(p>0.05).The parameters ADC and D of MR IVIM-DWI model has a good ability for distinguishing DM and MD patients(sensitivity were 0.706 and 0.775 respectively;specificity were 0.696 and 0.643 respectively).Conclusion: T2 mapping and IVIM-DWI could objectively distinguish the autoimmune inflammatory myopathy and muscular dystrophy patients.Compared with T2 mapping sequence,IVIM-DWI could be a good ability for distinguish autoimmune inflammatory myopathy(DM and NAM)and MD patients.Purpose:To explore MRI IVIM-DWI and DKI model of thigh muscles in patients with dermatomyositis.Methods:Ten normal volunteers and twenty-nine patients with DM were enrolled.Thirty-nine participants were evaluated nonquantitative MR imaging and axial IVIM and DKI from upper to lower thigh.The one way Analysis of Variance test was used to analysis the mean ADC?D?f?D* of IVIM model and MD?MK of DKI model in DM patients and control group.Results: The mean ADC,D,f value of IVIM-DWI model parameters and the mean MD,MK value of DKI model parameters showed a statistically significant difference between oedematous muscles,unaffected muscles(non-oedematous muscles in DM patients)and normal muscles.The mean ADC value of oedematous muscles group were higher than non-oedematous muscles and normal muscles(p<0.05),for the mean D value of oedematous muscles group were higher on average and showed a statistically significant difference when compared with unaffected and normal muscles(p<0.05),and the mean D value of unaffected muscles were lower showed a statistically significant difference when compared with normal muscles(p<0.05),the mean f value of non-oedematous muscles were higher on average when compared with oedematous muscles and normal muscles(p<0.05),the mean D* value of normal muscles showed higher than oedematous muscles and non-oedematous muscles groups(p<0.05).The mean MD value of oedematous muscles group were higher than non-oedematous muscles and normal muscles(p<0.05),wihle these parameters were no statistical difference between non-oedematous muscles in patients and normal muscles(p>0.05),the mean MK value of oedematous muscles was lower than the non-oedematous muscles and normal muscles(p<0.05).Conclusion: the IVIM-DWI and DKI model of MR imaging could objectively evaluate the water molecule diffusion properties of involved muscles in DM patients.