Bone Scintigraphy in Complex Regional Pain Syndrome Type I: A Pictorial Review

Introduction: Complex Regional Pain Syndrome type 1 (CRPS 1) is a chonlc pain syndrome Involving persistent, often severe pain, usually In an upper or lower extremity, most commonly following traumatic Injury. Depending on the stage, It is often followed by associated changes In skin color, temperature changes, halr loss, nail changes, and In advanced cases, limb atrophy. Since CRPS 1 Is a clinical diagnosis without typical laboratory or radiographic findings , bone eclntigraphy has been useful to confirm or exclude the diagnosis. The aim of this exhibit Is to familiarize the reader with (1) our protocol for performing dual phase bone scans in patients referred for CRPS 1, and (2) the typical and atypical bone scan findings of the different stages of the syndrorne.

Methods: The patients are referred to either confirm the clinical suspicion of CRPS 1 in uncertain cases, to determine the stage, or to exclude other causes of chonlc limb pain. Using a whole body scanner, inltllal blood pool Images after tracer injection are acquired either fom the pelvis to the feet , or from the shoulders to the hands, for evaluation of the lower extremities or upper extremities, respectively. This is followed by delayed Imaging of the respective areas 3-4 hours later

Results: We have observed several bone scan patterns of CRPS 1, depending on the cllnlcal stage, both typical and atypical. The scan findings in each presented case In this exhibit are correlated with the patient's clinical signs and symptoms.

Conclusions: The advantage of the bone scan Is to provide objective evidence of CRPS 1, to Identify the particular stage, and to exclude other causes of chonlc llmb pain. Recognition of both common and uncommon scan patterns will aid the imaging specialist in providing an accuriite and useful scan report.