Multimodal Ultrasonography in the Diagnosis and Treatment of Chronic Thyrotoxic Myopathy: A Prospective Study

Roumei Wang¹Rui Huang¹Shien Fu¹Yunxia Tang²Yaoli Liu^1*

• ¹First Affiliated Hospital, Guangxi Medical University, Nanning, Guangxi Zhuang Region, China
• ²Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, Guangxi Zhuang Region, China

Objective: This study integrates high-frequency ultrasonography with shear wave elastography (SWE) to perform a multimodal quantitative assessment of the rectus femoris musculature and thyroid tissue architecture in patients with chronic thyrotoxic myopathy (CTM). ByA novel predictive model for CTM progression was developed by quantitatively assessing biomechanical parameters, including muscle fibrosis progression and thyroid parenchymal stiffness, a novel predictive model for CTM progression was developed, providing an objective imaging-based foundation for early disease intervention.Methods: This prospective study enrolled 75 patients with hyperthyroidism and 53 healthy controls. SWE was used for quantitatively assessing theThe biomechanical parameters of the rectus femoris muscle and thyroid tissue were quantitatively assessed using SWE. Receiver operating characteristic (ROC) curve analysis was performed to evaluate the predictive efficacy of rectus femoris and thyroid tissue elasticity parameters for CTM diagnosis. A multivariate logistic regression model was developed to investigate the association between muscle fibrosis severity, thyroid stiffness, and CTM risk. Additionally, patients with CTM received pharmacotherapeutic interventions, and clinical indexes were administered to patients with CTM,systematically monitored along with systematic monitoring of clinical indices and dynamic changes in thyroid and rectus femoris correlation parameters before and after treatment to evaluate the therapeutic efficacy.The CTM group exhibited a significantly lower mean Young's modulus (E-mean) of the rectus femoris than the non-CTM and healthy groups (p < 0.01), suggesting muscle fibrosis. ROC curve analysis revealed that the combined diagnostic approach achieved the highest sensitivity and specificity for CTM, with an area under the curve of 92.5%. A multivariate logistic regression model revealed that, after adjusting for confounding factors, both rectus femoris E-mean and thyroid E-mean were significant predictors of CTM. SignificantFollowing treatment with antihyperthyroid drugs, significant improvements were observed in thyroid hormone levels, upper and lower limb muscle function tests, and muscle-related parameters compared with their pretreatment levels following treatment with antihyperthyroid drugs, with all differences reaching statistical significance (p < 0.01).By quantitatively assessing the morphological and biomechanical characteristics of the rectus femoris and thyroid gland, multimodal ultrasonography can provide a reliable imaging basis for the early prediction and therapeutic monitoring of CTM.