Dynamic bone imaging in the investigation of local bone pathology--when is it useful?

The aim of this work was to establish when, in the investigation of local musculoskeletal symptoms, dynamic isotope bone imaging yields useful information not available from static isotope bone imaging, using 99mTc methylene diphosphonate. One hundred and forty-two dynamic bone scans were reviewed, with particular reference to the site being imaged, the suspected underlying pathology, and the contribution of the dynamic phases to diagnosis, management, and eventual outcome. All were performed as part of the investigation of adult patients complaining of localized musculoskeletal symptoms. The dynamic phases influenced diagnosis, management, and eventual outcome most positively in suspected infection, particularly at a previous fracture site or around a prosthesis. They did not alter management significantly in suspected fracture, avascular necrosis, in most patients with pain of unknown cause, and were rarely helpful in imaging the axial skeleton. We suggest that, in the context of routine bone imaging, dynamic bone scanning should be reserved for cases of suspected infection. In the investigation of most other local bone pathologies, the static phase of the bone scan provides all the diagnostic information which is required for management decisions.