Context

In the USA, symptomatic nephrolithiasis leading to flank or kidney pain is responsible for over two million annual visits to the emergency department, amounting to a burden on the country's healthcare system of over $5 billion (£3 billion) annually.1 CT is the most accurate imaging modality for the evaluation of suspected acute renal colic due to its superior sensitivity and specificity for detection of renal and ureteral stones.2 However, CT scans also come with a greater exposure to potentially harmful ionising radiation (as well as increased cost). In this manuscript, the authors derive and validate an objective clinical prediction …