HIGH-VOLTAGE ELECTRIC INJURY - ASSESSMENT OF MUSCLE VIABILITY WITH MR-IMAGING AND TC-99M PYROPHOSPHATE SCINTIGRAPHY

PURPOSE: To evaluate use of magnetic resonance (MR) imaging and techne tium-99m pyrophosphate (PYP) scintigraphy in preoperative assessment o f muscle viability after high-voltage electric injury. MATERIALS AND M ETHODS: Twelve injured limbs were studied. Immediate, equilibrium, and delayed Tc-99m PYP scintigrams and gadolinium-enhanced and unenhanced MR images were obtained. Imaging results were compared with clinical findings.RESULTS: Scintigraphy demonstrated nonperfusion in four limbs that were subsequently amputated, but MR imaging had poor sensitivity in nonperfused regions owing to lack of edema. Tc-99m PYP uptake incr eased at transition zones between normal and nonperfused regions. MR i maging allowed further characterization of these zones by demonstratin g edema as enhancing (perfused) or nonenhancing (nonperfused). In all nonamputated limbs, edema showed enhancement. CONCLUSION: In high-volt age electric injury, gadolinium-enhanced MR imaging appears able to de monstrate zones of potential viability within radionuclide-avid tissue but has poor perfusion sensitivity when used alone.