МР–РЕЛАКСОМЕТРИЯ В ДИАГНОСТИКЕ РАБДОМИОЛИЗА

Abstract

Purpose. Assessing the possibilities of quantitative MRI in the diagnosis and monitoring of the course of rhabdomyolysis of various etiologies. Materials and methods. The results of MRI performed by 80 patients with clinical manifestations of rhabdomyolysis were analyzed. The diagnosis of rhabdomyolysis was confirmed by measuring the level of myoglobin (more than 70 μg/l) and CPK (more than 1000 IU/l) in the absence of laboratory and instrumental signs of myocardial damage. Scanning was carried out using T1, T2, STIR protocols, as well as the developed pulse sequences for calculating the relaxation times T1, T2 and T2*. Patients underwent MR examination at least 3 times during the course of the disease. Results. In 48 cases was detected a hyperintensive signal from muscle tissue on the T2 and STIR protocols. In 25 cases were identified MR signs of rhabdomyolysis, 16 of which were confirmed by laboratory methods and or biopsy of the affected muscle. One patient with a blood myoglobin level (577 ng/ml) showed no pathological changes in MR images. Thus, in the analyzed group, the sensitivity and specificity were 94% and 71%. Quantification protocols obtained relaxation times for the affected muscle tissue. The ROC analysis method determined cutoff thresholds for rhabdomyolysis: T1 greater than 1152 ms, T2 greater than 63 ms and T2* greater than 48 ms with sensitivity and specificity, respectively: 94% and 73%, 94% and 84%, 88% and 85%. Dynamic changes in the relaxation time during the recovery of patients had correlation relationships of high and medium strength with the main laboratory markers of rhabdomyolysis. The highest values of the correlation coefficient were found between T2 and the activity of CPK, ALS, and AST (rs = 0.805, 0.813, and 0.803; p <0.05). Conclusion. An improved technique for muscle MRI with a quantitative assessment of T2 relaxation time has high sensitivity and specificity (94% and 82%) in the diagnosis of rhabdomyolysis. Recovery of