SPECT bone scanning of the spine

Radionuclide bone scanning is a well accepted method for uncovering a variety of bony lesions including abnormalities of vertebral bodies that may be causing spinal pain. Single photon emission computed tomography (SPECT) is especially useful in such an evaluation because it allows for precise localization of a lesion to the vertebral body, disc space, or vertebral arch. This anatomic distinction is necessary in order to accurately diagnose the underlying condition detected by the bone scan. Most bony abnormalities result in focal areas of abnormal tracer activity but do not affect all components of a vertebra with equal frequency nor have a random pattern of involvement. Vertebral diseases tend to conform to predictable patterns that can be more readily identified by SPECT than planar imaging. Metastatic tumors commonly involve the posterior portion of the vertebral body, often in combination with a pedicle. Extensive abnormalities involving the vertebral body and vertebral arch, but sparing the pedicles, are usually benign as are lesions isolated to articular facets and lamina or disc space. Postoperative patients have additional potential problems including pseudarthrosis and complications following use of internal fixation devices including pedicle screws. Nuclear medicine physicians must speak the language of their referring physicians who are anatomically oriented and used to the exquisite morphologic detail of computed tomography (CT) and magnetic resonance imaging (MRI). SPECT allows for greater anatomic information compared with planar imaging as well as straightforward comparison with other tomographic-based studies such as CT and MRI.