Use of low-dose CT KUB: is it becoming the easy way out?

In 1995, Smith and colleagues first proposed the use of low-dose CT KUB for the diagnosis of ureteric colic [1]. Since then, popularity of this imaging modality has increased due to a number of reasons: a sensitivity of 94 to 97%, a specificity of 96 to 99%, lack of intravenous contrast injection and speed of examination. The UK College of Emergency Medicine considers CT KUB as best practice for radiological investigation of renal colic. A review of the literature suggests that the true positive rate (number of patients diagnosed with an obstructing or symptom causing calculus) should be between 47.5 and 67% and alternative diagnoses should be confirmed in approximately 10% of patients imaged [2].