HSS Ultrasound Case of the Month Case 119

Clinical History 56 yo male with acute painful swelling of one elbow with MRI showing a nonspecific aggressive synovitis.

Ultrasound-guided aspiration was requested to rule out septic arthritis.

Ultrasound of the Month – Case 119

1

Ultrasound of the Month – Case 119

2

Ultrasound of the Month – Case 119

3

Ultrasound of the Month – Case 119

4

Diagnosis: Gout Discussion Gout is a crystal deposition disease in which tophi made up of monosodium urate form in soft tissues, including within joints, and incite an inflammatory arthritis.

Elevation of serum uric acid is suggestive, but a definitive diagnosis requires the identification of negatively birefringent monosodium urate crystals in the affected site.

Ultrasound is a cost-effective imaging modality for assessing a joint that could potentially be affected by an inflammatory arthritis.

Ultrasound also has the advantage of allowing guided arthrocentesis.

Ultrasound of the Month – Case 119

5

Discussion continued On ultrasound, the classic features of a joint affected with gout include:  hyperechoic mass-like intraarticular deposits reflecting tophaceous material  a layer of hyperechoic material lining the articular cartilage, referred to as the “double contour sign”, representing uric acid crystals  Accompanying synovitis (joint effusion with synovial hyperemia).

Double contour sign, from Thiele RG, Schlesinger N. Diagnosis of gout by ultrasound.

Rheumatology 2007;46:1116-1121

Ultrasound of the Month – Case 119

6