Longitudinal (A) and transverse (B) ultrasound images of the right kidney showing an echogenic stone (arrowheads) with posterior acoustic shadowing (dashed arrows). One year later the patient presented with right flank pain and microscopic hematuria (C, D). There is now moderate hydronephrosis, and the stone has migrated into the proximal right ureter (arrowhead) with posterior acoustic shadowing (dashed arrow).
