Urinary tract disorders can cause calculi (stones), nephrocalcinosis (calcification of the renal parenchyma), and obstruction. Calculi can be seen on CT and ultrasound and come in various shapes and sizes. Nephrocalcinosis causes focal or diffuse renal calcification and can be caused by hypercalcemia, hyperparathyroidism, or renal tubular acidosis. Urinary tract obstruction leads to dilation of the renal pelvis and ureters and can be identified and localized with ultrasound or IVU. CT is also useful for evaluating acute obstruction. Common causes include stones, tumors, strictures, congenital issues, and retroperitoneal fibrosis.