The aim: To establish indicators and significance of sonography in the evaluation of muscle necrosis in ischemia of the limb acording to quantitative ultrasonographic indicators and density of collagen by histological method. Materials and methods: In experiments, rabbits modeled with 6-hour limb ischemia by applying an elastic tourniquet. On days 5, 15, and 30, ultrasound and histological studies of the muscles and correlation analysis were performed between the muscles’ entropy and the degree of their damage (atrophy, fibrosis and necrosis). Results: The relative amount of structurally altered tissue was estimated morphometrically and compared with entropy. A high correlation of muscle damage with vertical δ-entropy indicates that sonography is highly likely to detect areas of necrosis and, to a lesser extent, fibrosis in the development of ischemic limb contracture in the early stages. Conclusions: Vertical δ-entropy in sonography is a significant indicator of muscle damage after traumatic ischemia and has strong relationship with muscle fibrosis.