Imaging of renal colic

Ureterolithiasis is a common disease responsible for a large number of admi ssions in emergency departments and a wide utilization of imaging studies. The purpose of this review was to analyze the respective role of the differ ent available imaging techniques. Intravenous urography is the gold-standar d for diagnosis of acute obstruction, but positive detection of a stone may prove difficult at times. US is less accurate than urography for both diag noses of obstruction and lithiasis, but it represents a non invasive altern ative to IVU (no ionizing radiation and no IV contrast). The information ob tained from measurements of intra-renal resistive index is poorly contribut ive. Non contrast helical CT has become the gold-standard for the diagnosis of ureterolithiasis, the two main factors limiting its widespread use are its accessibility and the radiation exposure. Nevertheless, its excellent d iagnostic performance tends to dramatically reduce the need for IVU.