Annals of the Rheumatic Diseases 2009;68:1609-1612
CLINICAL AND EPIDEMIOLOGICAL RESEARCH
Concise reportDual energy computed tomography in tophaceous gout
1 Division of Rheumatology, Vancouver General Hospital, University of British Columbia, Vancouver, Canada
2 Arthritis Research Centre of Canada, Vancouver, Canada
3 Radiology Department, Department of Medicine, Vancouver General Hospital, University of British Columbia, Vancouver, Canada
Correspondence to Dr H K Choi, Division of Rheumatology, Department of Medicine, University of British Columbia, Arthritis Research Centre of Canada, 895 West 10th Avenue, Vancouver, BC V5Z 1L7, Canada; hchoi{at}arthritisresearch.ca
Objective: To evaluate the potential utility of a dual energy CT (DECT) scan in assessing urate deposits among patients with tophaceous gout, and obtain computerised quantification of tophus volume in peripheral joints.
Methods: 20 consecutive patients with tophaceous gout and 10 control patients with other arthritic conditions were included. DECT scans were performed using a renal stone colour-coding protocol that specifically assessed the chemical composition of the material (ie, urate coloured in red, calcium coloured in blue). An automated volumetric assessment of DECT was used to measure the volume of urate deposits in all peripheral joint areas.
Results: All 20 patients with gout showed red colour-coded urate deposits on their DECT scans, whereas none of 10 controls showed urate deposits. DECT scans revealed a total of 440 areas of urate deposition in 20 patients, whereas physical examination showed 111 areas of urate deposition (mean 22 vs 6 per patient, respectively, p<0.001). Total urate volume in a given patient ranged from 0.63 cm3 to 249.13 cm3, with a mean of 40.20 cm3.
Conclusions: DECT scans can produce obvious colour displays for urate deposits and help to identify subclinical tophus deposits. Furthermore, tophus volume can be measured by DECT scans through an automated volume estimation procedure.
Register for free content
The full back archive is now available for all BMJ Journals. Institutional subscribers may access the entire archive as part of their subscription. Personal subscribers will also have access to all content when logged in. Non-subscribers who register have free access to all articles published before 2006 right back to volume 1 issue 1. Register here to access the free archive of all BMJ Journals.
Don't forget to sign up for content alerts so you keep up to date with all the articles as they are published.
