Fatty Atrophy of Supraspinatus and Infraspinatus Muscles: Accuracy of US

PURPOSE: To prospectively evaluate the accuracy of ultrasonography (US) in depicting fatty atrophy of the supraspinatus (SSP) and infraspinatus (ISP) muscles, with magnetic resonance (MR) imaging as the reference standard.

MATERIALS AND METHODS: Institutional review board approval and informed consent were obtained. SSP and ISP muscles of 65 consecutive patients (27 women, 38 men; mean age, 53.1 years; range, 28–83 years) with possible rotator cuff tears were evaluated with US in two planes. Visibility of muscle contour, pennate pattern, the central tendon, and muscle echogenicity was assessed by two radiologists. On the basis of these findings, diagnosis of substantial fatty atrophy was made at US. Accuracy, sensitivity, specificity, proportion of over- and underestimations, and interobserver agreement in diagnosis of substantial (grade 2 or greater) muscle atrophy were determined. Fatty atrophy was graded at MR imaging as follows: score of 0 = no intramuscular fat, score of 1 = some fatty streaks, score of 2 = fat evident but less extensive than muscle, score of 3 = fat equal to muscle, and score of 4 = fat more extensive than muscle.

RESULTS: For readers 1 and 2, the accuracy of US in depicting fatty atrophy of SSP muscle was 75% (49 of 65) and 72% (47 of 65), sensitivity was 89% (eight of nine) and 100% (nine of nine), and specificity was 73% (41 of 56) and 68% (38 of 56), respectively. For readers 1 and 2, the accuracy of US in depicting fatty atrophy of ISP muscle was 85% (55 of 65) and 80% (52 of 65), sensitivity was 58% (11 of 19) and 63% (12 of 19), and specificity was 96% (44 of 46) and 87% (40 of 46), respectively. Overestimation of SSP muscle atrophy was more common (23% [15 of 65] for reader 1 and 28% [18 of 65] for reader 2) than underestimation (2% [one of 65] for reader 1 and 0% [0 of 65] for reader 2). For readers 1 and 2, overestimation of ISP muscle atrophy was 3% (two of 65) and 9% (six of 65) and underestimation was 12% (eight of 65) and 9% (seven of 65), respectively. Interobserver agreement was moderate for SSP (κ = 0.55) and substantial for ISP (κ = 0.71) muscles.

CONCLUSION: US is moderately accurate in the diagnosis of substantial fatty atrophy of the SSP or ISP muscle.

© RSNA, 2005


  • 1 GoutallierD, Postel JM, Lavau L, Bernageau J. Impact of fatty degeneration of the supraspinatus and infraspinatus muscles on the prognosis of surgical repair of the rotator cuff [in French]. Rev Chir Orthop Reparatrice Appar Mot1999;85:668–676. MedlineGoogle Scholar
  • 2 GoutallierD, Postel JM, Gleyze P, Leguilloux P, Van Driessche S. Influence of cuff muscle fatty degeneration on anatomic and functional outcomes after simple suture of full-thickness tears. J Shoulder Elbow Surg2003;12:550–554. Crossref, MedlineGoogle Scholar
  • 3 GerberC, Fuchs B, Hodler J. The results of repair of massive tears of the rotator cuff. J Bone Joint Surg Am2000;82:505–515. Crossref, MedlineGoogle Scholar
  • 4 UhthoffHK, Matsumoto F, Trudel G, Himori K. Early reattachment does not reverse atrophy and fat accumulation of the supraspinatus: an experimental study in rabbits. J Orthop Res2003;21:386–392. Crossref, MedlineGoogle Scholar
  • 5 GoutallierD, Postel JM, Bernageau J, Lavau L, Voisin MC. Fatty muscle degeneration in cuff ruptures: pre- and postoperative evaluation by CT scan. Clin Orthop Relat Res1994;(304):78–83. MedlineGoogle Scholar
  • 6 ZanettiM, Gerber C, Hodler J. Quantitative assessment of the muscles of the rotator cuff with magnetic resonance imaging. Invest Radiol1998;33:163–170. Crossref, MedlineGoogle Scholar
  • 7 FuchsB, Weishaupt D, Zanetti M, Hodler J, Gerber C. Fatty degeneration of the muscles of the rotator cuff: assessment by computed tomography versus magnetic resonance imaging. J Shoulder Elbow Surg1999;8:599–605. Crossref, MedlineGoogle Scholar
  • 8 WienerSN, Seitz WH Jr. Sonography of the shoulder in patients with tears of the rotator cuff: accuracy and value for selecting surgical options. AJR Am J Roentgenol1993;160:103–107. Crossref, MedlineGoogle Scholar
  • 9 TakagishiK, Makino K, Takahira N, Ikeda T, Tsuruno K, Itoman M. Ultrasonography for diagnosis of rotator cuff tear. Skeletal Radiol1996;25:221–224. Crossref, MedlineGoogle Scholar
  • 10 SofkaCM, Haddad ZK, Adler RS. Detection of muscle atrophy on routine sonography of the shoulder. J Ultrasound Med2004;23:1031–1034. Crossref, MedlineGoogle Scholar
  • 11 ZanettiM, Hodler J. Imaging of degenerative and posttraumatic disease in the shoulder joint with ultrasound. Eur J Radiol2000;35:119–125. Crossref, MedlineGoogle Scholar
  • 12 RobertsonPL, Schweitzer ME, Mitchell DG, et al. Rotator cuff disorders: interobserver and intraobserver variation in diagnosis with MR imaging. Radiology1995;194:831–835. LinkGoogle Scholar
  • 13 HodlerJ, Kursunoglu-Brahme S, Snyder SJ, et al. Rotator cuff disease: assessment with MR arthrography versus standard MR imaging in 36 patients with arthroscopic confirmation. Radiology1992;182:431–436. LinkGoogle Scholar
  • 14 VadVB, Warren RF, Altchek DW, O'Brien SJ, Rose HA, Wickiewicz TL. Negative prognostic factors in managing massive rotator cuff tears. Clin J Sport Med2002;12:151–157. Crossref, MedlineGoogle Scholar
  • 15 TingartMJ, Apreleva M, Lehtinen JT, Capell B, Palmer WE, Warner JJ. Magnetic resonance imaging in quantitative analysis of rotator cuff muscle volume. Clin Orthop Relat Res2003;415:104–110. Crossref, MedlineGoogle Scholar
  • 16 SeiboldCJ, Mallisee TA, Erickson SJ, Boynton MD, Raasch WG, Timins ME. Rotator cuff: evaluation with US and MR imaging. RadioGraphics1999;19:685–705. LinkGoogle Scholar
  • 17 TeefeySA, Hasan SA, Middleton WD, Patel M, Wright RW, Yamaguchi K. Ultrasonography of the rotator cuff: a comparison of ultrasonographic and arthroscopic findings in one hundred consecutive cases. J Bone Joint Surg Am2000;82:498–504. Crossref, MedlineGoogle Scholar
  • 18 ReimersK, Reimers CD, Wagner S, Paetzke I, Pongratz DE. Skeletal muscle sonography: a correlative study of echogenicity and morphology. J Ultrasound Med1993;12:73–77. Crossref, MedlineGoogle Scholar
  • 19 ReimersCD, Fleckenstein JL, Witt TN, Muller-Felber W, Pongratz DE. Muscular ultrasound in idiopathic inflammatory myopathies of adults. J Neurol Sci1993;116:82–92. Crossref, MedlineGoogle Scholar
  • 20 RutherfordOM, Jones DA. Measurement of fibre pennation using ultrasound in the human quadriceps in vivo. Eur J Appl Physiol Occup Physiol1992;65:433–437. Crossref, MedlineGoogle Scholar
  • 21 MeyerDC, Hoppeler H, von Rechenberg B, Gerber C. A pathomechanical concept explains muscle loss and fatty muscular changes following surgical tendon release. J Orthop Res2004;22:1004–1007. Crossref, MedlineGoogle Scholar
  • 22 YaoL, Mehta U. Infraspinatus muscle atrophy: implications? Radiology2003;226:161–164. LinkGoogle Scholar
  • 23 PfirrmannCW, Schmid MR, Zanetti M, Jost B, Gerber C, Hodler J. Assessment of fat content in supraspinatus muscle with proton MR spectroscopy in asymptomatic volunteers and patients with supraspinatus tendon lesions. Radiology2004;232:709–715. LinkGoogle Scholar
  • 24 KostlerH, Kenn W, Hummer C, Bohm D, Hahn D. 2D-SPLASH spectroscopy to determine the fat/water ratio in the muscle of the rotator cuff [in German]. Rofo2002;174:991–995. Crossref, MedlineGoogle Scholar

Article History

Published in print: Nov 2005