Sonographic twinkling artifact for diagnosis of acute ureteral calculus.

OBJECTIVE

We compared the performance of color Doppler twinkling artifacts with B-ultrasound and computed tomography (CT) for diagnosis of ureteral calculus in patients with acute renal colic.

METHODS

The location and size of ureteral stones in 2268 patients with acute renal colic were determined using the two ultrasound methods and CT. All cases were followed up for 2-8 weeks.

RESULTS

Color Doppler twinkling artifacts had a sensitivity of 96.98%, specificity of 90.39%, positive predictive value (PPV) of 99.77%, and negative predictive value (NPV) of 41.23%. B-Ultrasound had a sensitivity of 96.39%, specificity of 80.77%, PPV of 99.53%, and NPV of 34.43%. CT had a sensitivity of 99.59%, specificity of 94.23%, PPV of 99.86%, and NPV of 84.48%. The area under the receiver operating characteristic curve was 0.925 for color Doppler twinkling artifacts, 0.863 for B-ultrasound, and 0.963 for CT.

CONCLUSION

For the diagnosis of ureteral calculus, the sonographic twinkling artifact had a similar performance as CT. We suggest use of the sonographic twinkling artifact instead of CT for patients with acute renal colic to reduce the examination time and exposure to radiation, and to provide earlier access to treatment.