Figure 3
From: US detection of renal and ureteral calculi in patients with suspected renal colic
![Figure 3](http://media.springernature.com/full/springer-static/image/art%3A10.1186%2F2036-7902-5-S1-S3/MediaObjects/13089_2013_Article_59_Fig3_HTML.jpg)
Two small renal stones with calyceal dilatation. Grey-scale sonogram shows only one hyperechoic spot with posterior acoustic shadowing. Color Doppler sonogram reveals two twinkling signs.