Presentation
Left colicky acute onset flan pain. Hydronephrosis? Calculus?
Patient Data
Multiple 2-5 mm kidney stones with pronounced twinkling in the dilated left pelvicalyceal system.
Left hydroureter which can be followed to the crossing of the iliac vessels where a 12 mm stone is visible, the distal ureter is not distended and is hard to discern.
Follow-up CT KUB after conservative therapy:
The left renal and ureteric stones are in an identical posititon, accompanied by moderate hydroureter and pelvicalyceal dilation.
Relatively enlarged left ovary, planned ob/gyn workup recommended.
Small umbilical hernia.
Case Discussion
Ultrasound is generally considered as a secondary imaging modality for ureteric calculi, however in patients with optimal body habitus its performance can be excellent. While most ureteric stones on US are detected in either the proximal ureteropelvic or in the distal vesicoureteric junctions, whenever a hydroureter is seen we should make an attempt to follow it down. The crossing of the iliac vessels is another potential hotspot where ureteric calculi can be temporarily or permanently trapped.