Combining Hyperechoic Aggregates and the Double-Contour Sign Increases the Sensitivity of Sonography for Detection of Monosodium Urate Deposits in Gout.

Objectives: To compare the sensitivities of individual and combined sonography of hyperechoic aggregates and the double-contour sign in detecting monosodium urate (MSU) crystal deposits in gouty joints.

Methods: Monosodium urate crystal deposits in symptomatic and contralateral asymptomatic joints of 70 patients with acute gout were evaluated by sonography of hyperechoic aggregates and the double-contour sign individually and in combination. All patients with acute gout in this study had at least 1 symptomatic joint with MSU deposits determined by dual-energy computed tomography.

Results: Of 195 symptomatic joints (92 in the upper limbs and 103 in the lower limbs) and an equal number of asymptomatic joints: (1) 97.14% (68 of 70) of patients had hyperechoic aggregate/double-contour sign-positive joints versus 74.29% (52 of 70) with double-contour sign-positive and 63.89% (46 of 70) with hyperechoic aggregate-positive joints; (2) 86.96% (80 of 92) of the symptomatic upper limb joints were double-contour sign/hyperechoic aggregate positive versus 46.74% (43 of 92) that were double-contour sign positive and 70.65% (65 of 92) that were hyperechoic aggregate positive; and (3) 98.06% (101 of 103) of the symptomatic lower limb joints were double-contour sign/hyperechoic aggregate positive versus 92.23% (95 of 103) that were double-contour sign positive and 41.75% (43 of 103) that were hyperechoic aggregate positive.

Conclusions: Hyperechoic aggregates and the double-contour sign in combination improve the investigative sensitivity of sonography than either hyperechoic aggregates or the double-contour sign individually for detecting MSU crystal deposits in gouty joints.