Renal (ureteric) colic is a common surgical emergency. It is usually caused by calculi obstructing the ureter, but about 15% of patients have other causes, e.g. extrinsic compression, intramural neoplasia or an anatomical abnormality . Up to 12 percent of the population will have a urinary stone during their lifetime, and recurrence rates approach 50 percent . Fifty-five percent of those with recurrent stones have a family history of urolithiasis  and having such a history increases the risk of stones by a factor of three . Upon presentation to the A&E department, suspected acute renal colic patients must have a clinical examination and radiological investigations to confirm the diagnosis .
The best imaging study to confirm the diagnosis of a urinary stone in a patient with acute flank pain is unenhanced, helical CT of the abdomen and pelvis . If CT is unavailable, plain abdominal radiography should be performed, since 75 to 90 percent of urinary calculi are radiopaque . Although ultrasonography has high specificity (greater than90 percent), its sensitivity is much lower than that of CT, typically in the range of 11 to24 percent . Thus, ultrasonography is not used routinely but is appropriate as the initial imaging test when colic occurs during pregnancy .
Published on: Feb 1, 2016 Pages: 8-10