technetium-tc-99m-pyrophosphate and Muscular-Diseases

We aimed to assess the specificity and sensitivity of (99m)technetium pyrophosphate muscle scintigraphy in the diagnostic workup of patients with suspected myopathy. We reviewed the charts of 166 patients; 52% of the subjects had myalgias, 36% had muscle weakness, 45% had an elevated serum creatine kinase (CK), and 49% had an increased C reactive protein (CRP). Scintigraphy was positive in 34 patients (20%). The test was more sensitive in the presence of muscle weakness, elevated CK, or increased CRP. The presence of myalgias did not influence the odds. Sensitivity was 60% in patients with the final diagnosis of polymyositis, dermatomyositis, or inclusion body myositis, and 70% in noninflammatory myopathies. Eight percent had false positive scintigrams. In individuals with biopsy-proven myopathy (51 subjects), the diagnostic sensitivity was 43%, and its specificity was 60%. Low positive and high negative likelihood ratios (5.0 and 0.65, respectively) document an only limited diagnostic efficiency of (99m)Tc-PYP scintigraphy in the evaluation of inflammatory and noninflammatory myopathies and suggest that the test is not helpful in the routine diagnostic workup of muscle complaints, even after a priori selection of patients for CK plus CRP abnormalities.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Biomarkers; C-Reactive Protein; Creatine Kinase; Female; Humans; Male; Middle Aged; Muscle Weakness; Muscle, Skeletal; Muscular Diseases; Pain; Polymyositis; Radionuclide Imaging; Sensitivity and Specificity; Technetium Tc 99m Pyrophosphate

A 62-year-old woman was admitted to our hospital because of diplopia and muscular weakness. She had been diagnosed as having sarcoidosis histologically by skin biopsy 5 years before. Although neither CT nor MRI could detect the granulomas, 99mTc-pyrophosphate scintigraphy successfully detected the involvement of sarcoidosis not only in the skeletal muscles but also in the external ocular muscles. After treatment with prednisolone, the symptoms markedly subsided and increased uptake of radionucleotide disappeared. Although 67Ga scintigraphy is also known to be useful in investigating the sites affected by sarcoidosis throughout the body, it was not effective in detecting the involvement of external ocular muscle due to the physiological uptake of 67Ga to the lacrimal grands. While the granulomas are frequently observed histologically in skeletal muscles, usually they are not associated with muscle symptoms. In our study 99mTc-pyrophosphate scintigraphy has proven to be useful in investigating the nodular lesions in skeletal muscles of sarcoidosis than 67Ga scintigraphy.

Topics: Female; Follow-Up Studies; Humans; Middle Aged; Muscle, Skeletal; Muscular Diseases; Oculomotor Muscles; Ophthalmoplegia; Radionuclide Imaging; Radiopharmaceuticals; Sarcoidosis; Technetium Tc 99m Pyrophosphate

A retrospective review was done of 34 extremities studied between 1981 and 1985 with technetium-99m pyrophosphate scanning; 22 were subsequently amputated. Results of detailed pathologic examination or immediate postoperative examination of the resected extremity were available in 16 cases. In these cases, scanning had allowed correct prediction of the level of amputation and of the specific areas of muscle infarction in 13 cases. In the one case in which amputation was performed for infection rather than muscle necrosis, the lack of necrosis was correctly predicted with the scan. The limited results of this study indicate that the Tc-99m pyrophosphate scan allows the location of necrotic muscle to be predicted accurately and may therefore be a useful adjunct in determining the best level for ultimate amputation. Special caution is required in those cases in which muscle necrosis is due to acute causes (e.g., traumatic thrombosis) rather than chronic vascular disease.

Topics: Amputation, Surgical; Diphosphates; Extremities; Humans; Muscles; Muscular Diseases; Necrosis; Radionuclide Imaging; Regional Blood Flow; Retrospective Studies; Technetium; Technetium Tc 99m Pyrophosphate

Topics: Adult; Angiography; Diphosphates; Hernia; Humans; Male; Muscular Diseases; Radionuclide Imaging; Technetium; Technetium Tc 99m Pyrophosphate; Thigh; Tomography, X-Ray Computed