Antimyosin scintigraphy in patients with acquired and hereditary muscular disorders

Abstract

Scintigraphy with indium-111 labelled antimyosin has an established role in the evaluation of cardiac muscle damage. This antibody has been shown to cross-react with myosin in skeletal muscle. We therefore studied the usefulness of this method for the detection of skeletal muscle lesions in rhabdomyolysis, myositis and hereditary muscular dystrophies. All nine patients with rhabdomyolysis had focal uptake of antimyosin antibody which correlated with the clinical findings of soft tissue damage. However, a number of symptomless lesions were also detected by immunoscintigraphy. In rhabdomyolysis the target to non-target uptake ratios varied from 1.3 to 7.6. Diffuse uptake of antibody in skeletal muscle was observed in all three patients with polymyositis-dermatomyositis and in 12 out of 13 patients with muscular dystrophies. In myositis the intensity of antibody accumulation correlated reasonably well with the magnitude of oedema detected by magnetic resonance imaging (MRI). Most patients with Becker type or non-X-chromosomal muscular dystrophies showed slight or moderate uptake of antibody, mainly in the lower extremities. In these patients more antibody accumulated in the calves than in the thighs, whereas the findings on MRI were more prominent in the thighs than in the calves, presumably because of the better preserved muscle bulk in the calves. We conclude that antimyosin scintigraphy can be used for the detection of muscle lesions not only in acquired muscle diseases but also in hereditary muscular disorders, and that immunoscintigraphy provides information on muscle disease activity not obtainable with MRI.

Antimyosin Scintigraphy Compared With Magnetic Resonance Imaging in Inflammatory Myopathies

“…In muscular dystrophies the better preserved muscle bulk in the calves accumulated more antibodies than the atrophic thigh muscles, which had more pronounced increases in signal intensity in T 1 -weighted MRI, reflecting replacement of muscle by fat. 5 Similar observations on the effect of fatty degeneration on MRI findings were made in our study on patients with myositis.…”

“…[13][14][15] Antimyosin scintigraphy, which has an established role in the evaluation of cardiac muscle damage, has also been used to detect traumatic skeletal muscle lesions. 5,16 The accumulation of antimyosin antibody is focal and often quite intensive in rhabdomyolysis, compared with the more diffuse or patchy antibody accumulation in myositis. In muscular dystrophies the better preserved muscle bulk in the calves accumulated more antibodies than the atrophic thigh muscles, which had more pronounced increases in signal intensity in T 1 -weighted MRI, reflecting replacement of muscle by fat.…”

Normal Post-Race Antimyosin Myocardial Scintigraphy in Asymptomatic Marathon Runners with Elevated Serum Creatine Kinase MB Isoenzyme and Troponin T Levels

“…Antimyosin imaging over the quadriceps femoris muscle was negative in all runners in contrast to positive antibody imaging reported elsewhere with rhabdomyolysis [35] and uptake in skeletal muscle of runners after race with 99mTc pyrophosphate [36].…”

Imaging Radiation Induced Muscular Necrosis with Antimyosin-Scintigraphy and Computed Tomography

“…The use of the antimyosin-antibody has been proposed by others to detect skeletal muscle damage caused by trauma (Elgazzar et al 1988;Malki et al 1992), rhabdomyolysis (Krause et al 1988;Murray et al 1997), soft tissue tumors (Kairemo et al 1990;Planting et al 1990;Farahati et al 1992), and dermatopolymyosistis (De Geeter et al 1989;Lofberg et al 1994). Several mechanisms leading to myosin exposure to its antibody could be operating in these different disease states: a primary defect of the sarcoplasmic membrane in dystrophic disease, inflammation and striated muscle cell destruction in myositis, striated muscle cell damage due to ischemia or suppression in rhabdomyolysis (Lofberg et al 1994).…”