Fishhook ureter sign

The fishhook ureter sign, also known as the hockey stick sign or the J-shaped ureter sign, is a radiologic sign that has been used to describe the presence of a retrocaval ureter, which is an anatomical anomaly where the ureter abnormally runs posterior to the IVC. This abnormality often results in hydroureter or hydronephrosis.^[1]

The fishook ureter sign also describes the appearance of the ureter in patients with bladder outlet obstruction due to benign prostatic hyperplasia (BPH).^[2]