The distribution of urate deposition within the extremities in gout: a review of 148 dual-energy CT cases

Clinical detection of gout can be difficult due to co-existent and mimicking arthropathies and asymptomatic disease. Understanding of the distribution of urate within the body can aid clinical diagnosis and further understanding of the resulting pathology. Our aim was to determine this distribution of urate within the extremities in patients with gout. All patients who underwent a four-limb dual-energy computed tomography (DECT) scan for suspected gout over a 2-year period were identified (n = 148, 121 male, 27 female, age range, 16-92 years, mean = 61.3 years, median = 63 years). The reports of the positive cases were retrospectively analyzed and the locations of all urate deposition recorded and classified by anatomical location. A total of 241 cases met the inclusion criteria, of which 148 cases were positive. Of these, 101 (68.2 %) patients had gout in the foot, 81 (56.1 %) in the knee, 79 (53.4 %) in the ankle, 41 (27.7 %) in the elbow, 25 (16.9 %) in the hand, and 25 (16.9 %) in the wrist. The distribution was further subcategorized for each body part into specific bone and soft tissue structures. In this observational study, we provide for the first time a detailed analysis of extremity urate distribution in gout, which both supports and augments to the current understanding based on clinical and microscopic findings. (orig.)