Min Liu, Presenter: Nothing to Disclose

Fan Yang, Abstract Co-Author: Nothing to Disclose

Chang Liu, Abstract Co-Author: Nothing to Disclose

Gout is the most common crystal deposition arthropathy currently diagnosed clinically due to frequently involving the first metatarsophalangeal joint. To our best knowledge, monosodium urate (MSU) crystal deposition in the sacroiliac joint has rarely been reported to date. The purpose of this study is to examine the features of MSU crystal deposition and erosion in sacroiliac gouty arthritis with dual-energy CT (DECT). 

This study was approved by an institutional review board; patient informed consent was obtained. Twelve patients (10 men, 2 women; mean age, 47 years±12 [standard deviation]) with sacroiliac gouty arthritis and 10 normal controls (6 men, 4 women; mean age, 49 years±13 [standard deviation]) were enrolled in this study. DECT with gout protocol was performed in all patients for detection of MSU crystal deposition and bone erosion. A dedicate post-processing gout software was used to observe the color-coding MSU crystal. Two readers scored blindly the DECT scans for MSU crystal deposition and erosion, and kappa test was used to determine the observer agreement. 

Of 12 patients, the serum urate levels were partly elevated (7 cases) and partly normal (5cases). MSU crystal deposition was observed in sacroilicac joints (7 cases), lumbar facet joints (5 cases) and discs sacroilicac joints (4 cases). Bone erosion was found in 6 cases. Compared with sacroiliac gouty arthritis patients, no MSU crystal deposition was detected in all normal controls (p<0.001). Good agreement was obtained between two reader for observing the MSU crystal deposition (κ= 0.93) and bone erosion (κ= 0.91).

DECT can serve as a promising imaging technique for visualization of MSU crystal deposition and erosion in sacroiliac gouty arthritis.

Diverse factors can lead to sacroilitis besides gout. Sometimes imaging differential diagnosis is difficult. DECT provides a relative new non-invasive imaging modality that is able to distinguish urate crystals. These findings will benefit the diagnosis of gouty arthritis.

Liu, M, Yang, F, Liu, C, Assessment of Sacroiliac Gouty Arthritis with Dual-energy CT: An Initial Study.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14014159.html