title: 99mTechnetium pyrophosphate scintigraphy in the detection of skeletal muscle disease.
abstract: 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.
authors.affiliation: Department of Rheumatology and Clinical Immunology, Albert-Ludwigs University Medical School, Hugstetterstr. 55, 79106 Freiburg, Germany. ulrich.walker@klinikum.uni-freiburg.de
authors.forename: U A
authors.initials: UA
authors.lastname: Walker
authors.forename: K
authors.initials: K
authors.lastname: Garve
authors.forename: I
authors.initials: I
authors.lastname: Brink
authors.forename: N
authors.initials: N
authors.lastname: Miehle
authors.forename: H H
authors.initials: HH
authors.lastname: Peter
authors.forename: T
authors.initials: T
authors.lastname: Kelly
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000378:metabolism; D002097:C-Reactive Protein / Q000032:analysis; D003402:Creatine Kinase / Q000097:blood; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018908:Muscle Weakness / Q000097:blood / Q000175:diagnosis / Q000000981:diagnostic imaging; D018482:Muscle, Skeletal / Q000000981:diagnostic imaging / Q000473:pathology*; D009135:Muscular Diseases / Q000097:blood / Q000175:diagnosis* / Q000000981:diagnostic imaging; D010146:Pain / Q000097:blood / Q000175:diagnosis / Q000000981:diagnostic imaging; D017285:Polymyositis / Q000097:blood / Q000175:diagnosis / Q000000981:diagnostic imaging; D011877:Radionuclide Imaging; D012680:Sensitivity and Specificity; D016698:Technetium Tc 99m Pyrophosphate
chemical_list: D015415:Biomarkers; D016698:Technetium Tc 99m Pyrophosphate; D002097:C-Reactive Protein; D003402:Creatine Kinase