Status Of Multimodal Magnetic Resonance Imaging Of Idiopathic Inflammatory Myopathy

Objective: To explore the characteristics of thigh muscles of patients with Idiopathic inflammatory myopathy on diffusion tensor imaging and conventional MRI.Method: 30 patients from the First Hospital of China Medical University with IIM were collected as patient group and recruit 20 volunteers as the control group.collect the imaging images of routine MRI and DTI of thighs in all subjects.conventional MRI images were analyzed by two imaging physicians.Post-processing of the DTI image using the SIEMENS NMR workbench.The following parameters of each muscle were calculated from DTI images: average diffusion coefficient(ADC),fractional anisotropy(FA)and three Eigenvalues(? 1>? 2>? 3).The comparison between edema muscles and normal muscles were analyzed respectively using Student's t-test in SPSS21.0.Result: Conventional MRI showed that all 30 patients in the case group showed muscle tissue edema,21 patients showed subcutaneous fat edema,25 patients had different degrees of fascial edema,and 7 patients had mild to moderate intramuscular fat infiltration or Fat replacement.Vastuslateralis showed highest ADC value in the control group and Gracilis showed the lowest FA.The ADC and three Eigenvalues of each edema muscle were statistically increased compared with normal muscle.The FA showed significant decrease in Vastuslateralis.Conclusion: Conventional MRI scan can clearly show the specific information of the involvement of muscle tissue in IIM patients,which can provide some assistance for clinical work.Fatty infiltration and calcification can also occur in muscle tissue of patients with longer duration.DTI studies have shown that there are some differences in DTI parameters in normal human muscle tissue,but the results of each study are not very consistent.In the case group,the measured ADC,?1,?2,and ?3 of the muscles were significantly increased compared with the control group,and the FA value of the gracilis muscle was significantly reduced.The difference of DTI parameters can be explained by a series of pathological changes in the muscle tissue of the IIM patients.However,there are other possible explanations for some results.In summary,conventional MRI and DTI sequences can provide a theoretical basis for the study of IIM myopathy in different directions.