Abstract:

 Objective  To study the twinkling artifact and acoustic shadowing of renal stones on Doppler sonography, and to evaluate the clinical significance of the twinkling artifact in the diagnosis of renal stones. Methods  With CT as a reference standard, renal stones were classified into groups of smaller than 5 mm, 5~10 mm and greater than 10 mm. The frequency of the twinkling artifact and acoustic shadowing in each different group was observed. Subjects were grouped as normal, overweight, or obese based on the body mass index (BMI). The correlation between the twinkling artifact of renal stones and BMI was assessed. Results  The detection rate of the twinkling artifact was much higher than that of acoustic shadowing in all groups, especially in the groups of smaller than 5 mm and 5~10 mm (P<0.01). No relationship between the twinkling artifact and BMI was found (P>0.05). Conclusion  The twinkling artifact is not influenced by stone size and BMI. It is useful in the diagnosis of renal stones, especially small stones with faint or absent posterior acoustic shadowing.

Key words: Ultrasonography, doppler, color; Twinkling artifact; Acoustic shadowing; Renal stones