Keisuke Matsuki1, Atsuya Watanabe2, Shunsuke Ochiai2, Tomonori Kenmoku3, Nobuyasu Ochiai4, Takayuki Obata5, Tomoaki Toyone2, Yuichi Wada2, Toshiyuki Okubo6. 1. Department of Orthopaedic Surgery, Teikyo University Chiba Medical Center, Ichihara, Japan. Electronic address: keisk-m@bf6.so-net.ne.jp. 2. Department of Orthopaedic Surgery, Teikyo University Chiba Medical Center, Ichihara, Japan. 3. Department of Orthopaedic Surgery, Kitazato University East Hospital, Sagamihara, Japan. 4. Department of Orthopaedic Surgery, Chiba University Graduate School of Medicine, Chiba, Japan. 5. Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, Chiba, Japan. 6. Department of Radiology, Teikyo University Chiba Medical Center, Ichihara, Japan.
Abstract
BACKGROUND: Although fatty degeneration of the rotator cuff muscles has been reported to affect the outcomes of rotator cuff repairs, only a few studies have attempted to quantitatively evaluate this degeneration. T2 mapping is a quantitative magnetic resonance imaging technique that potentially evaluates the concentration of fat in muscles. The purpose of this study was to investigate fatty degeneration of the rotator cuff muscles by using T2 mapping, as well as to evaluate the reliability of T2 measurement. METHODS: We obtained magnetic resonance images including T2 mapping from 184 shoulders (180 patients; 110 male patients [112 shoulders] and 70 female patients [72 shoulders]; mean age, 62 years [range, 16-84 years]). Eighty-three shoulders had no rotator cuff tear (group A), whereas 101 shoulders had tears, of which 62 were incomplete to medium (group B) and 39 were large to massive (group C). T2 values of the supraspinatus and infraspinatus muscles were measured and compared among groups. Intraobserver and interobserver variabilities also were examined. RESULTS: The mean T2 values of the supraspinatus in groups A, B, and C were 36.3 ± 4.7 milliseconds, 44.2 ± 11.3 milliseconds, and 57.0 ± 18.8 milliseconds, respectively. The mean T2 values of the infraspinatus in groups A, B, and C were 36.1 ± 5.1 milliseconds, 40.0 ± 11.1 milliseconds, and 51.9 ± 18.2 milliseconds, respectively. The T2 value significantly increased with the extent of the tear in both muscles. Both intraobserver and interobserver variabilities were more than 0.99. CONCLUSION: T2 mapping can be a reliable tool to quantify fatty degeneration of the rotator cuff muscles.
BACKGROUND: Although fatty degeneration of the rotator cuff muscles has been reported to affect the outcomes of rotator cuff repairs, only a few studies have attempted to quantitatively evaluate this degeneration. T2 mapping is a quantitative magnetic resonance imaging technique that potentially evaluates the concentration of fat in muscles. The purpose of this study was to investigate fatty degeneration of the rotator cuff muscles by using T2 mapping, as well as to evaluate the reliability of T2 measurement. METHODS: We obtained magnetic resonance images including T2 mapping from 184 shoulders (180 patients; 110 male patients [112 shoulders] and 70 female patients [72 shoulders]; mean age, 62 years [range, 16-84 years]). Eighty-three shoulders had no rotator cuff tear (group A), whereas 101 shoulders had tears, of which 62 were incomplete to medium (group B) and 39 were large to massive (group C). T2 values of the supraspinatus and infraspinatus muscles were measured and compared among groups. Intraobserver and interobserver variabilities also were examined. RESULTS: The mean T2 values of the supraspinatus in groups A, B, and C were 36.3 ± 4.7 milliseconds, 44.2 ± 11.3 milliseconds, and 57.0 ± 18.8 milliseconds, respectively. The mean T2 values of the infraspinatus in groups A, B, and C were 36.1 ± 5.1 milliseconds, 40.0 ± 11.1 milliseconds, and 51.9 ± 18.2 milliseconds, respectively. The T2 value significantly increased with the extent of the tear in both muscles. Both intraobserver and interobserver variabilities were more than 0.99. CONCLUSION: T2 mapping can be a reliable tool to quantify fatty degeneration of the rotator cuff muscles.
Authors: Carly A Lockard; Katharine J Wilson; Charles P Ho; Richard C Shin; J Christoph Katthagen; Peter J Millett Journal: Skeletal Radiol Date: 2017-12-01 Impact factor: 2.199