Thirteen-megahertz ultrasound probe: its role in diagnosing localized scleroderma

Background Ultrasound imaging has been shown to be useful for the evaluation of systemic and localized scleroderma (LS). However, its specificity and sensitivity have not been studied. Objectives To define morphological ultrasound diagnostic criteria in LS and to test their sensitivity and specificity with a 13-MHz ultrasound probe. Methods Forty plaques in 26 consecutive patients with LS were examined and compared blindly with 17 control plaques in 16 patients with skin diseases where LS was in the differential diagnosis. Data were also compared with a normal control group. Five patients were re-evaluated 12-18 months after the first examination. Results Ultrasound examination disclosed a characteristic dense image resembling a flattened 'yo-yo'. Undulations of the dermis, disorganization, loss of thickness and thickened hyperechoic bands in the hypodermis, and the 'yo-yo' image had a high sensitivity and a high specificity for LS. A 92% sensitivity and a 100% specificity for LS were found when at least four of these five signs were present. Conclusions Thirteen-megahertz ultrasound is a valuable tool for diagnosing LS. Morphological ultrasound diagnostic criteria had a high specificity and a high sensitivity.