Abstract
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Objectives: Bone scintigraphy [BS], although quite sensitive to detect skeletal lesions, has a comparatively low specificity. Hybrid-cameras combining single-photon emission computed tomography [SPECT] and helical CT offer the opportunity to correlate scintigraphic information with high-quality visualization of morphology in one session. This may lead to an improvement in diagnostic accuracy. The purpose of this study was to assess the diagnostic impact of SPECT/CT on interpretation of lesions of the extremities in orthopedic pts, which were visualized on BS. Pts with a history of malignancy were excluded from the study.
Methods: 65 pts with suspected orthopedic disorders underwent conventional three phase BS and SPECT/CT of upper (n = 20) and lower extremities (n = 51). Imaging was performed due to pain with the following suspected clinical diagnoses: osteoarthritis [OA] (n = 15), rheumatoid arthritis [RA] (n = 9), trauma (n = 7), or osteomyelitis / infection [OM] (n = 22). 12 pts presented with an unclear pain syndrome of the extremities. First, BS and SPECT were interpreted without knowledge of clinical information. In a second step the corresponding fused SPECT/CT images were analyzed.
Results: From BS and SPECT osteoarthritis was diagnosed in 32/65 pts, RA in 2/65 pts, OM in 15/65 pts, and a traumatic lesion in 8/65 pts. 4/71 pts showed no abnormal bone metabolism in the extremities despite pain. A tumor-like-lesion was suspected in 4/65 patients. SPECT/CT changed diagnosis in 21/65 (32%) pts as shown in the figure.
Conclusions: SPECT/CT increased diagnostic accuracy in one third of patients with orthopedic disorders affecting the extremities when compared to stand-alone SPECT and planar scintigraphy.
- Society of Nuclear Medicine, Inc.