This examination demonstrates the typical intravenous pyelogram (IVP) features of collecting system dilatation and a delayed nephrogram secondary to a distal obstructing calculus. In this case, the calculus is well seen radiographically.  

Treatment depends on the location of the stone, composition and size.

Irrespective of stone composition, patients who present with renal colic require assessment. Approximately 90% of stones less than 4 mm are likely to pass down the ureter and into the bladder, and thus often require no more than analgesia and hydration ¹.