Imaging for Urinary Calculi

Abstract

The accurate diagnosis of urinary calculi is essential for treatment planning. Non-contrast- enhanced computed tomography (NCCT) is considered the gold standard for adults to diagnose urolithiasis in acute flank pain. Generally, CT has also overtaken the role of intravenous urography in stone diagnosis and treatment planning. Lower dose CT seems to be as accurate as NCCT for the same purpose. Ultrasonography (US) is considered first-line imaging for urolithiasis in paediatric and preg­nancy groups of patients. Various iterations of US, especially with the Doppler setting, can improve diagnostic accuracy, whereas mag­netic resonance imaging may be an alternative investigation tool for pregnant women. Plain radiographs and US scans can be combined for stone surveillance purposes. The study of stone composition can be inferred from double-energy CT scans. Differential kidney function is conventionally derived from nuclear renogram, but recently, CT-derived parameters have been shown to be a promising alternative.