Arthritis & Rheumatism, Volume 62,
November 2010 Abstract Supplement

Abstracts of the American College of
Rheumatology/Association of Rheumatology Health Professionals
Annual Scientific Meeting
Atlanta, Georgia November 6-11, 2010.


Ultrasound Detects More Erosions in Gout Than Conventional Radiography.

Thiele2,  Ralf G., Schlesinger1,  Naomi

UMDNJ/RWJMS
University of Rochester, Rochester, NY

Background:

Ultrasound (US) can be helpful in the assessment of gout. Typical tophaceous deposits, erosions and synovial hyperemia can be detected [1, 2]. Conventional radiography (CR) is widely used to image characteristic erosions with sharp margins and overhanging edges. However, in the detection of erosions, CR has inherent disadvantages when compared with cross-sectional imaging. In CR, a three-dimensional bony structure is summarized on a two-dimensional film. Bony erosions can therefore only be confirmed if they are seen in profile, and a break in the cortical margin is demonstrated. Cross-sectional imaging including US detects more erosions in rheumatoid arthritis (RA).

Previous studies compared 2 radiographic views with US findings. In this study, 3 radiographic views are compared with findings on standardized US examination.

Objectives:

To compare detection of erosions with US and CR in chronic gout.

Methods:

Retrospectively, US studies performed during a 12 months period were reviewed. 42 patients with a history of crystal proven gout, US images and CR of corresponding joints were identified. The study was limited to assessment of first MTP joints. Complete data for 62 joints were available. All US studies were performed according to published guidelines, by a rheumatologist certified in musculoskeletal ultrasound, with >15 years US experience. Linear transducers with frequencies between 14–18 MHz were used. Erosions were defined as breaks in the cortical contour of metatarsal head or proximal phalanx, seen in two perpendicular planes. Tophaceous material was defined as hyperechoic crystalline concrements with a "wet clumps of sugar" appearance. Calcified tophi were defined as hyperechoic concrements with a pronounced posterior accoustic shadow.

In contrast to previous studies, 3 different radiographic views of the feet were obtained to facilitate detection of erosions. The radiologist's final impression was counted. At the time of the study, the sonographer was unaware of the CR results.

Results:

Using US, erosions were seen in 41/62 joints (66%). Using multiview CR, erosions were seen in 21/62 of the same joints (34%). Intra-articular calcification was seen in 3/62 joints (5%) using US and 3/62 joints (5%) using CR. Intra-articular tophaceous material was seen in 59/62 joints (95%) using US and 0/62 joints (0%) using CR. Tophaceous material was seen within the erosion in 36/62 joints (58%).

Conclusion:

US identified almost twice as many erosions as CR in gouty joints. The addition of a third radiographic view improved the yield only marginally over previous studies that used two CR views to assess erosions in gout. If tophi calcify, they are seen both with CR and US, but uncalcified tophaceous material escapes CR visualization. Similar to findings in RA, CR remains an imperfect tool for the assessment of erosions in gout when compared with US.

References:

[1]ThieleSchlesinger, R.G.N., Diagnosis of gout by ultrasound. Rheumatology (Oxford), 2007

[2]ThieleSchlesinger, R.G.N., Ultrasonography shows disappearance of monosodium urate crystal deposition on hyaline cartilage after sustained normouricemia is achieved. Rheumatol Int.,2010

To cite this abstract, please use the following information:
Thiele, Ralf G., Schlesinger, Naomi; Ultrasound Detects More Erosions in Gout Than Conventional Radiography. [abstract]. Arthritis Rheum 2010;62 Suppl 10 :889
DOI: 10.1002/art.28657

Abstract Supplement

Meeting Menu

2010 ACR/ARHP