Diagnosis of urinary calculi: Value of `twinkling artifact' assessed by color Doppler ultrasound

The value of the color Doppler artifact known as the twinkling sign in the diagnosis of urinary calculi is assessed. Sixty-five patients with 83 urinary tract calculi seen on intravenous pyelography were examined. The sonographic examinations included gray-scale, color Doppler, power Doppler, and spectral evaluations of the calculus using an Acuson Sequoia 512. The twinkling artifact was found within and/or distal to 80 of the 83 urinary tract calculi, where as the gray-scale ultrasonic scanner only detected 64 of the 83 calculi. The twinkling sign was found to effectively differentiate a very small stone from other small echogenic structures.