Full Papers
Detection of myositis in a rat model by shear wave elastography and dispersion imaging based on muscle viscoelasticity
Y. Xin1, M. Li2, D. Li3, Y. Liu4, W. Li5, J. Zhu6
- Department of Ultrasound, Peking University People’s Hospital, Beijing, China.
- Department of Ultrasound, Peking University People’s Hospital, Beijing, China.
- Department of Ultrasound, Peking University People’s Hospital, Beijing, China.
- Department of Ultrasound, Peking University People’s Hospital, Beijing, China.
- Department of Ultrasound, Peking University People’s Hospital, Beijing, China.
- Department of Ultrasound, Peking University People’s Hospital, Beijing, China. zhujiaan@pkuph.edu.cn
CER19694
Full Papers
PMID: 43001847 [PubMed]
Received: 15/01/2026
Accepted : 20/04/2026
In Press: 28/10/2026
Abstract
OBJECTIVES:
This study aimed to assess the feasibility and diagnostic effectiveness of shear wave dispersion imaging (SWDI) and shear wave elastography (SWE) in evaluating myositis through the development of an experimental autoimmune myositis (EAM) rat model.
METHODS:
EAM was induced in 48 female Lewis rats by immunisation with rabbit skeletal muscle homogenate, while 8 normal rats
were included as a control group. Throughout the study period, 8 EAM rats were randomly selected weekly from the initial immunisation to the sixth immunisation for clinical monitoring, serological analysis, muscle SWDI and SWE assessments, and muscle histopathology examination. The severity of EAM was determined based on clinical observations, serological findings, and muscle histopathology grading. Additionally, correlation analyses were conducted to assess the relationship between shear wave dispersion slope (SWDS) and shear wave speed (SWS) with muscle pathology.
RESULTS:
After 4 weeks post-immunisation, clinical scores and serum CK levels peaked in EAM rats. Histological analysis revealed extensive muscle fiber degeneration, necrosis, inflammatory cell infiltration and interstitial vessel involvement. A strong positive correlation was observed between CK (r=0.729, p<0.001) and clinical scores (r=0.753, p<0.001) with the pathology grading. The SWDS and SWS of the muscles in EAM rats were significantly lower compared to normal controls in both transverse and longitudinal sections, decreasing with the progression of myositis (p<0.05). A significant negative correlation was found between shear wave parameters and muscle pathology grading (p<0.001). SWDS and SWS demonstrated high diagnostic accuracy for EAM, with the AUC of SWDS being higher in transverse sections, while the AUC of SWS being higher in longitudinal sections, although the difference was not statistically significant (p>0.05).
CONCLUSIONS:
SWDI and SWE are valuable tools for assessing inflammatory lesions in skeletal muscle and evaluating myositis severity.
