title: Predicting Retear after Repair of Full-Thickness Rotator Cuff Tear: Two-Point Dixon MR Imaging Quantification of Fatty Muscle Degeneration-Initial Experience with 1-year Follow-up.
abstract: Purpose To determine the degree of preoperative fatty degeneration within muscles, postoperative longitudinal changes in fatty degeneration, and differences in fatty degeneration between patients with full-thickness supraspinatus tears who do and those who do not experience a retear after surgery. Materials and Methods This prospective study had institutional review board approval and was conducted in accordance with the Committee for Human Research. Informed consent was obtained. Fifty patients with full-thickness supraspinatus tears (18 men, 32 women; mean age, 67.0 years ± 8.0; age range, 41-91 years) were recruited. The degrees of preoperative and postoperative fatty degeneration were quantified by using a two-point Dixon magnetic resonance (MR) imaging sequence; two radiologists measured the mean signal intensity on in-phase [S(In)] and fat [S(Fat)] images. Estimates of fatty degeneration were calculated with "fat fraction" values by using the formula S(Fat)/S(In) within the supraspinatus, infraspinatus, and subscapularis muscles at baseline preoperative and at postoperative 1-year follow-up MR imaging. Preoperative fat fractions in the failed-repair group and the intact-repair group were compared by using the Mann-Whitney U test. Results The preoperative fat fractions in the supraspinatus muscle were significantly higher in the failed-repair group than in the intact-repair group (37.0% vs 19.5%, P < .001). Fatty degeneration of the supraspinatus muscle tended to progress at 1 year postoperatively in only the failed-repair group. Conclusion MR imaging quantification of preoperative fat fractions by using a two-point Dixon sequence within the rotator cuff muscles may be a viable method for predicting postoperative retear. (©) RSNA, 2016.
authors.affiliation: From the Departments of Radiology (T.N., S.H., J.O., J.S., Y.S.) and Orthopaedic Surgery (A.T.), St Luke's International Hospital, 9-1 Akashi-cho, Chuo-ku, Tokyo 104-8560, Japan; Department of Radiological Sciences, University of California, Irvine, Calif (T.N., H.Y.); and Department of Intelligent Image Information, Division of Regeneration and Advanced Medical Sciences, Gifu University Graduate School of Medicine, Gifu, Japan (T.H.).
authors.forename: Taiki
authors.initials: T
authors.lastname: Nozaki
authors.affiliation: From the Departments of Radiology (T.N., S.H., J.O., J.S., Y.S.) and Orthopaedic Surgery (A.T.), St Luke's International Hospital, 9-1 Akashi-cho, Chuo-ku, Tokyo 104-8560, Japan; Department of Radiological Sciences, University of California, Irvine, Calif (T.N., H.Y.); and Department of Intelligent Image Information, Division of Regeneration and Advanced Medical Sciences, Gifu University Graduate School of Medicine, Gifu, Japan (T.H.).
authors.forename: Atsushi
authors.initials: A
authors.lastname: Tasaki
authors.affiliation: From the Departments of Radiology (T.N., S.H., J.O., J.S., Y.S.) and Orthopaedic Surgery (A.T.), St Luke's International Hospital, 9-1 Akashi-cho, Chuo-ku, Tokyo 104-8560, Japan; Department of Radiological Sciences, University of California, Irvine, Calif (T.N., H.Y.); and Department of Intelligent Image Information, Division of Regeneration and Advanced Medical Sciences, Gifu University Graduate School of Medicine, Gifu, Japan (T.H.).
authors.forename: Saya
authors.initials: S
authors.lastname: Horiuchi
authors.affiliation: From the Departments of Radiology (T.N., S.H., J.O., J.S., Y.S.) and Orthopaedic Surgery (A.T.), St Luke's International Hospital, 9-1 Akashi-cho, Chuo-ku, Tokyo 104-8560, Japan; Department of Radiological Sciences, University of California, Irvine, Calif (T.N., H.Y.); and Department of Intelligent Image Information, Division of Regeneration and Advanced Medical Sciences, Gifu University Graduate School of Medicine, Gifu, Japan (T.H.).
authors.forename: Junko
authors.initials: J
authors.lastname: Ochi
authors.affiliation: From the Departments of Radiology (T.N., S.H., J.O., J.S., Y.S.) and Orthopaedic Surgery (A.T.), St Luke's International Hospital, 9-1 Akashi-cho, Chuo-ku, Tokyo 104-8560, Japan; Department of Radiological Sciences, University of California, Irvine, Calif (T.N., H.Y.); and Department of Intelligent Image Information, Division of Regeneration and Advanced Medical Sciences, Gifu University Graduate School of Medicine, Gifu, Japan (T.H.).
authors.forename: Jay
authors.initials: J
authors.lastname: Starkey
authors.affiliation: From the Departments of Radiology (T.N., S.H., J.O., J.S., Y.S.) and Orthopaedic Surgery (A.T.), St Luke's International Hospital, 9-1 Akashi-cho, Chuo-ku, Tokyo 104-8560, Japan; Department of Radiological Sciences, University of California, Irvine, Calif (T.N., H.Y.); and Department of Intelligent Image Information, Division of Regeneration and Advanced Medical Sciences, Gifu University Graduate School of Medicine, Gifu, Japan (T.H.).
authors.forename: Takeshi
authors.initials: T
authors.lastname: Hara
authors.affiliation: From the Departments of Radiology (T.N., S.H., J.O., J.S., Y.S.) and Orthopaedic Surgery (A.T.), St Luke's International Hospital, 9-1 Akashi-cho, Chuo-ku, Tokyo 104-8560, Japan; Department of Radiological Sciences, University of California, Irvine, Calif (T.N., H.Y.); and Department of Intelligent Image Information, Division of Regeneration and Advanced Medical Sciences, Gifu University Graduate School of Medicine, Gifu, Japan (T.H.).
authors.forename: Yukihisa
authors.initials: Y
authors.lastname: Saida
authors.affiliation: From the Departments of Radiology (T.N., S.H., J.O., J.S., Y.S.) and Orthopaedic Surgery (A.T.), St Luke's International Hospital, 9-1 Akashi-cho, Chuo-ku, Tokyo 104-8560, Japan; Department of Radiological Sciences, University of California, Irvine, Calif (T.N., H.Y.); and Department of Intelligent Image Information, Division of Regeneration and Advanced Medical Sciences, Gifu University Graduate School of Medicine, Gifu, Japan (T.H.).
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yoshioka
mesh_terms: D000273:Adipose Tissue / Q000000981:diagnostic imaging / Q000473:pathology*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001182:Arthroscopy; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000000981:diagnostic imaging / Q000473:pathology*; D011183:Postoperative Complications / Q000175:diagnosis*; D011237:Predictive Value of Tests; D011300:Preoperative Care / Q000379:methods; D011446:Prospective Studies; D012008:Recurrence; D017006:Rotator Cuff / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D000070636:Rotator Cuff Injuries / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery*