Assessment of Liver Stiffness in a Rat Model of Type 2 Diabetes Using Shear Wave Elastography

Background/Objectives: Type 2 diabetes mellitus (T2DM) is associated with progressive hepatic alterations, including steatosis and fibrosis, which may affect liver mechanical properties. Shear wave elastography (SWE) is a non-invasive imaging technique that enables quantitative assessment of tissue stiffness; however, its application in diabetic animal models remains limited. This study aimed to evaluate liver elasticity using SWE in a high-fat diet (HFD) and streptozotocin (STZ)-induced rat model of T2DM, using histopathological examination as the reference standard. Methods: Twenty-four rats were randomly allocated to either a control group (n = 12) or a diabetic group (n = 12). Diabetes was induced using HFD feeding followed by low-dose STZ administration. Liver elasticity was assessed in vivo using SWE at two examination sessions. Shear wave velocity measurements were obtained from eight liver regions of interest and expressed in meters per second (m/s). Following euthanasia, liver tissues were subjected to histopathological evaluation using hematoxylin and eosin, Masson's trichrome, and periodic acid-Schiff staining. Results: Diabetic rats demonstrated marked histopathological alterations, including macrovesicular and microvesicular steatosis, hepatocellular vacuolization, increased collagen deposition, and glycogen depletion. Collagen deposition was significantly greater in diabetic animals, while glycogen content was significantly reduced (3.70 ± 1.05 vs. 26.87 ± 2.87; p < 0.05). SWE revealed consistently higher liver shear wave velocities in diabetic rats compared with controls at both examination sessions. Although liver stiffness increased over time in both groups, these changes did not reach statistical significance. Conclusions: HFD/STZ-induced diabetes was associated with increased liver stiffness and histopathological evidence of hepatic injury and fibrosis. SWE may represent a feasible non-invasive approach for assessing diabetes-related changes in liver mechanical properties.