title: The diagnostic value of biexponential apparent diffusion coefficients in myopathy.
abstract: To investigate the performance of a biexponential signal decay model using DWI in myopathies and to differentiate Polymyositis (PM)/Dermatomyositis (DM), Glycogen Storage Diseases (GSDs) and Muscular Dystrophies (MDs) utilizing diffusion-weighted imaging. 11 healthy volunteers (control group) and 46 patients with myopathy were enrolled in the retrospective study. 27 of 46 patients had PM/DM, 7 patients GSDs and 12 patients MDs. After conventional MR sequences, diffusion weighted imaging with a b-factor ranging from 0 to 1200 s/mm(2) was performed on both thighs. The intra-muscular signal-to-noise ratios (SNRs) on multiple-b DWI images were measured for 7 different muscles and compared among the different groups. The median T2 signal intensity and biexponential apparent diffusion coefficients (ADC), including standard ADC, fast ADC, and slow ADC values, were compared among the different groups. The intra-muscular SNRs were statistically significantly different depending on the b value, and also found among the 4 groups (p < 0.05). The median T2 signal intensity of the normal muscles in control group was statistically significantly lower than that of edematous muscles in the PM/DM, GSDs and MDs groups (p = 0.000), while there were no statistically significant differences among the PM/DM, GSDs, and MDs groups (p > 0.05). The median standard ADC value of the edematous muscles in GSDs was statistically significantly lower than that of normal muscles in the control group (p = 0.000) and the median ADC value of the edematous muscles in PM/DM patients was statistically significantly greater than that of the GSDs (p = 0.000) and MDs groups (p = 0.005). The median slow ADC value of the edematous muscles in MDs patients and PM/DM patients was statistically significantly greater than that of GSDs patients (p < 0.05). Intra-muscular SNR decay curves and biexponential ADC parameters are useful in distinguishing among PM/DM, GSDs, and MDs.
authors.affiliation: Department of Radiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, No. 1095, Jiefang Road, Wuhan, 430030, Hubei, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Ran
authors.affiliation: Department of Radiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, No. 1095, Jiefang Road, Wuhan, 430030, Hubei, China.
authors.forename: Yao
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Department of Radiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, No. 1095, Jiefang Road, Wuhan, 430030, Hubei, China.
authors.forename: Dong
authors.initials: D
authors.lastname: Sun
authors.affiliation: Department of Radiology, St John's Medical Center, Tulsa, OK, USA.
authors.forename: John
authors.initials: J
authors.lastname: Morelli
authors.affiliation: Department of Radiology, Third Hospital of Hebei Medical University, Shijiazhuang, Hebei, China.
authors.forename: Ping
authors.initials: P
authors.lastname: Zhang
authors.affiliation: Department of Radiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, No. 1095, Jiefang Road, Wuhan, 430030, Hubei, China.
authors.forename: Gang
authors.initials: G
authors.lastname: Wu
authors.affiliation: Department of Radiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, No. 1095, Jiefang Road, Wuhan, 430030, Hubei, China.
authors.forename: Yuda
authors.initials: Y
authors.lastname: Sheng
authors.affiliation: Department of Radiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, No. 1095, Jiefang Road, Wuhan, 430030, Hubei, China.
authors.forename: Ruyi
authors.initials: R
authors.lastname: Xie
authors.affiliation: Department of Radiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, No. 1095, Jiefang Road, Wuhan, 430030, Hubei, China.
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Department of Radiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, No. 1095, Jiefang Road, Wuhan, 430030, Hubei, China. lilyboston2002@163.com.
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Li
mesh_terms: D000328:Adult; D000368:Aged; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000000981:diagnostic imaging*; D009135:Muscular Diseases / Q000145:classification / Q000175:diagnosis*; D012189:Retrospective Studies; D059629:Signal-To-Noise Ratio; D055815:Young Adult
keywords: Biexponential apparent diffusion coefficients; Dermatomyositis; Glycogen storage diseases; Magnetic resonance imaging; Muscular Dystrophies; Polymyositis