The diagnostic value of the twinkle sign in color Doppler imaging of urinary stones

ObjectiveTo determine the diagnostic value of the color Doppler twinkle sign in the diagnosis of urinary stones.MethodsThe study examined 100 urinary stones in 71 patients who presented with urinary symptoms and were suspected to have urinary stones. Patients were examined by gray scale and color Doppler ultrasound as well as non-contrast spiral computed tomography (CT), with CT used as the reference standard. The twinkle sign was identified as a color artifact associated with urinary stones, presenting as rapidly changing colors seen posterior to a reflector.ResultsA total of 100 stones were detected in 71 patients by non-contrast spiral CT. Of the 100 stones, 62 (62%) caused a posterior acoustic shadow and 58 (58%) showed echogenicity on B-mode ultrasound, while 68 (68%) caused the twinkle sign on color Doppler sonography.ConclusionIdentification of the twinkle sign on Doppler ultrasound can improve ultrasound detection of urinary calculi.