Reliability Assessment of Ultrasound Muscle Echogenicity in Patients with Rheumatic Diseases: Results of a Multicenter International Web-based Study

Methods: Forty-two rheumatologists and 2 radiologists from 13 countries were asked to assess US muscle echogenicity of quadriceps muscle in 80 static images and 20 clips from 64 patients with different rheumatic diseases and 8 healthy subjects. Two visual scales were evaluated, a visual semi-quantitative scale (0-3) and a continuous quantitative measurement ("VAS echogenicity," 0-100). The same assessment was repeated to calculate intra-observer reliability. US muscle echogenicity was also calculated by an independent research assistant using a software for the analysis of scientific images (ImageJ). Inter and intra reliabilities were assessed by means of prevalence-adjusted bias-adjusted Kappa (PABAK), intraclass correlation coefficient (ICC) and correlations through Kendall's Tau and Pearson's Rho coefficients.

Results: The semi-quantitative scale showed a moderate inter-reliability [PABAK = 0.58 (0.57-0.59)] and a substantial intra-reliability [PABAK = 0.71 (0.68-0.73)]. The lowest inter and intra-reliability results were obtained for the intermediate grades (i.e., grade 1 and 2) of the semi-quantitative scale. "VAS echogenicity" showed a high reliability both in the inter-observer [ICC = 0.80 (0.75-0.85)] and intra-observer [ICC = 0.88 (0.88-0.89)] evaluations. A substantial association was found between the participants assessment of the semi-quantitative scale and "VAS echogenicity" [ICC = 0.52 (0.50-0.54)]. The correlation between these two visual scales and ImageJ analysis was high (tau = 0.76 and rho = 0.89, respectively).

Conclusion: The results of this large, multicenter study highlighted the overall good inter and intra-reliability of the US assessment of muscle echogenicity in patients with different rheumatic diseases.

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References

Cesari M, Landi F, Vellas B, Bernabei R, Marzetti E . Sarcopenia and physical frailty: two sides of the same coin. Front Aging Neurosci. 2014; 6:192. PMC: 4112807. DOI: 10.3389/fnagi.2014.00192. View

Perkisas S, Bastijns S, Baudry S, Bauer J, Beaudart C, Beckwee D . Application of ultrasound for muscle assessment in sarcopenia: 2020 SARCUS update. Eur Geriatr Med. 2021; 12(1):45-59. DOI: 10.1007/s41999-020-00433-9. View

Perkisas S, Baudry S, Bauer J, Beckwee D, De Cock A, Hobbelen H . Application of ultrasound for muscle assessment in sarcopenia: towards standardized measurements. Eur Geriatr Med. 2021; 9(6):739-757. DOI: 10.1007/s41999-018-0104-9. View

Thomaes T, Thomis M, Onkelinx S, Coudyzer W, Cornelissen V, Vanhees L . Reliability and validity of the ultrasound technique to measure the rectus femoris muscle diameter in older CAD-patients. BMC Med Imaging. 2012; 12:7. PMC: 3342139. DOI: 10.1186/1471-2342-12-7. View

Casey P, Alasmar M, Mclaughlin J, Ang Y, McPhee J, Heire P . The current use of ultrasound to measure skeletal muscle and its ability to predict clinical outcomes: a systematic review. J Cachexia Sarcopenia Muscle. 2022; 13(5):2298-2309. PMC: 9530572. DOI: 10.1002/jcsm.13041. View

Di Matteo A, Smerilli G, Cipolletta E, Wakefield R, De Angelis R, Risa A . Muscle involvement in systemic lupus erythematosus: multimodal ultrasound assessment and relationship with physical performance. Rheumatology (Oxford). 2022; 61(12):4775-4785. DOI: 10.1093/rheumatology/keac196. View

Wijntjes J, van Alfen N . Muscle ultrasound: Present state and future opportunities. Muscle Nerve. 2020; 63(4):455-466. PMC: 8048972. DOI: 10.1002/mus.27081. View

Chianca V, Albano D, Messina C, Gitto S, Ruffo G, Guarino S . Sarcopenia: imaging assessment and clinical application. Abdom Radiol (NY). 2021; 47(9):3205-3216. PMC: 8536908. DOI: 10.1007/s00261-021-03294-3. View

Pillen S, van Alfen N . Skeletal muscle ultrasound. Neurol Res. 2011; 33(10):1016-24. DOI: 10.1179/1743132811Y.0000000010. View

10.

Smerilli G, Castell S, Cipolletta E, Farah S, Carotti M, Salaffi F . Ultrasound measurement of muscle thickness at the proximal forearm in a rheumatologic setting. Clin Exp Rheumatol. 2020; 38(5):985-988. View

11.

Giovannini S, Brau F, Forino R, Berti A, DIgnazio F, Loreti C . Sarcopenia: Diagnosis and Management, State of the Art and Contribution of Ultrasound. J Clin Med. 2021; 10(23). PMC: 8658070. DOI: 10.3390/jcm10235552. View

12.

An H, Tizaoui K, Terrazzino S, Cargnin S, Lee K, Nam S . Sarcopenia in Autoimmune and Rheumatic Diseases: A Comprehensive Review. Int J Mol Sci. 2020; 21(16). PMC: 7461030. DOI: 10.3390/ijms21165678. View

13.

Sari A, Esme M, Aycicek G, Armagan B, Kilic L, Ertenli A . Evaluating skeletal muscle mass with ultrasound in patients with systemic sclerosis. Nutrition. 2020; 84:110999. DOI: 10.1016/j.nut.2020.110999. View

14.

Buckinx F, Landi F, Cesari M, Fielding R, Visser M, Engelke K . Pitfalls in the measurement of muscle mass: a need for a reference standard. J Cachexia Sarcopenia Muscle. 2018; 9(2):269-278. PMC: 5879987. DOI: 10.1002/jcsm.12268. View

15.

Chen L, Woo J, Assantachai P, Auyeung T, Chou M, Iijima K . Asian Working Group for Sarcopenia: 2019 Consensus Update on Sarcopenia Diagnosis and Treatment. J Am Med Dir Assoc. 2020; 21(3):300-307.e2. DOI: 10.1016/j.jamda.2019.12.012. View

16.

Albano D, Messina C, Vitale J, Sconfienza L . Imaging of sarcopenia: old evidence and new insights. Eur Radiol. 2019; 30(4):2199-2208. DOI: 10.1007/s00330-019-06573-2. View

17.

Tagliafico A, Bignotti B, Torri L, Rossi F . Sarcopenia: how to measure, when and why. Radiol Med. 2022; 127(3):228-237. PMC: 8960583. DOI: 10.1007/s11547-022-01450-3. View

18.

Kaya A, Kara M, Tiftik T, Tezcan M, Ozel S, Ersoz M . Ultrasonographic evaluation of the muscle architecture in patients with systemic lupus erythematosus. Clin Rheumatol. 2013; 32(8):1155-60. DOI: 10.1007/s10067-013-2249-8. View

19.

Paramalingam S, Morgan K, Becce F, Diederichsen L, Ikeda K, Mandl P . Conventional ultrasound and elastography as imaging outcome tools in autoimmune myositis: A systematic review by the OMERACT ultrasound group. Semin Arthritis Rheum. 2021; 51(3):661-676. DOI: 10.1016/j.semarthrit.2020.11.001. View

20.

Albayda J, van Alfen N . Diagnostic Value of Muscle Ultrasound for Myopathies and Myositis. Curr Rheumatol Rep. 2020; 22(11):82. PMC: 7522112. DOI: 10.1007/s11926-020-00947-y. View