Lower extremity scintigraphy: the foot and ankle.

Disorders of the ankle and foot are common and may pose a significant clinical problem. Acute injuries of the ankle and foot are routinely evaluated by radiographs and, if inconclusive, by magnetic resonance imaging (MRI) or computed tomagraphy (CT). In subacute or chronic injuries, where prolonged pain is unexplained, bone scintigraphy may play a significant role. The bone scan may differentiate soft tissue from bone pathology, and, being a sensitive test, it may indicate the region that needs further specific radiologic examination. It may also indicate the clinical significance of a radiologic finding. Moreover, in some clinical settings bone scintigraphy can be specific in the diagnosis. Careful attention to the technique enhances the efficiency of bone scintigraphy and SPECT allows better investigation of the hindfoot. The importance of ankle and foot injuries in the orthopedic practice and the better understanding of subacute and chronic injuries in athletes and in the general population has led to an increased use of specific tests such as MRI, CT, and bone scintigraphy. With improved technique and instrumentation it is no longer sufficient to indicate a focal abnormality in the ankle or foot on bone scintigraphy. More precise information about perfusion, blood pool, and specific location of a lesion can be obtained by high resolution and tomographic images. The role of bone scintigraphy in the diagnosis of such disorders will be presented with a focus on subacute traumatic injuries and related disorders, as well as its role in systemic inflammatory disorders that often involve the ankle and foot.