Radionuclide imaging of miscellaneous bone and joint conditions

A series of musculoskeletal pathological conditions (inflammatory, traumatic, infectious, and malignant) affect the bone and large or small joints; although very frequent, these conditions are sometimes considered not to be of “high priority.” These diseases often (but not always) arise with pain and can present atypical clinical symptoms that make diagnosis difficult, especially in the early stages of the onset. The main objective of this chapter is to focus on the most useful and appropriate methods (imaging with radionuclides, CT, and MRI) for a better, faster, and more accurate diagnosis in order to clarify the nature and extent of the disease. Since some of these conditions are associated with an increase in vascularization and/or local bone remodeling, diagnostic imaging with radionuclides is highly reliable. In case of suspicion or clear indication of altered bone turnover, or if conventional radiology or MRI is impractical (due to the presence of contraindications), bone scintigraphy with hybrid SPECT/CT imaging constitutes a milestone for the diagnosis of many skeletal conditions, as a very sensitive method. On the other hand, the gold standard method for early assessment of functional impairment due to infectious process or to detect and localize an occult infection is, to date, scintigraphy with in-vitro-labeled leukocytes; this procedure remains the first-line test when other imaging procedures yield equivocal or inconclusive/nondiagnostic information.