Steven John Co B.Sc; MD, Presenter: Nothing to Disclose

Yatin Chadha BS, Abstract Co-Author: Nothing to Disclose

Savvas Nicolaou MD, Abstract Co-Author: Nothing to Disclose

This study was performed to determine the sensitivity and specificity of dual energy CT in detecting monosodium urate deposition in patients with clinically diagnosed gout.

This is a retrospective review. The study group consists of 87 patients with clinically diagnosed gout based on standard rheumatological assessment by rheumatologists. This study group was further divided into subgroups consisting of 21 patients with aspirate proven gout and 35 patients with clinically discernable tophi. The control group is 16 patients with clinically diagnosed non-gouty arthritis. All patients had dual energy CT (DECT) scans performed using the Siemens DECT scanner. Clinical findings from each group were compared to DECT findings interpreted by a two radiologists to determine the sensitivity and specificity, respectively, for DECT in identifying MSU deposition. Rheumatology clinical diagnosis was used as the gold standard for this study.

In the study arm of 87 patients with clinically diagnosed gout, 84 patients (true positives) had DECT scans positive for monosodium urate, while 3 patients (false negatives) had negative scans (sensitivity = 84/87 = 96.6%). In the first subgroup of 21 patients with aspirate proven gout, all 21 showed monosodium urate deposition on DECT (sensitivity = 21/21 = 100%). Among the 35 patients with clinically detected tophi, all 35 were positive for monosodium urate on DECT (sensitivity = 35/35 = 100%). For the 16 patients with clinically diagnosed non-gouty arthropathy, all 16 (true negatives) had negative DECT scans (specificity = 16/16 = 100%). The positive predictive value of DECT for gout was determined to be 100%, while the negative predictive value was 84.2%.

DECT has a high sensitivity and specificity for the detection of monosodium urate.

DECT is highly accurate in detecting monosodium urate, which makes it a promising technique for diagnosing gout, detecting subclinical disease, monitoring disease burden, and guiding therapy.

Co, S, Chadha, Y, Nicolaou, S, Dual energy CT: In the Detection of Monosodium Urate in Patients with Gouty Arthropathy.  Radiological Society of North America 2010 Scientific Assembly and Annual Meeting, November 28 - December 3, 2010 ,Chicago IL. http://archive.rsna.org/2010/9012111.html