Plain radiography still is required in the planning of treatment for urolithiasis.

INTRODUCTION Nonenhanced computed tomography (NCT) is recognised as the most sensitive tool in diagnosis of renal tract calculi. However, its role as the sole imaging investigation, for decisions regarding management is less clear. OBJECTIVE To determine the proportion of new stone patient referrals in which management is altered by interpretation of a plain abdominal kidneys, ureters and bladder (KUB) radiograph in addition to NCT. METHODS One hundred consecutive new referrals to a national lithotripsy centre were considered prospectively for treatment of renal tract calculi. RESULTS A significant change in management was undertaken in 17 patients on the basis of KUB findings. Eleven patients had radio-lucent ureteric stones, for which Extracorporeal Shockwave Lithotripsy (ESWL) was consequently not possible and who required endoscopic management. There were six inaccuracies in measurement of size or positioning on NCT. In a further 43 patients it was not possible to confirm management until the KUB was reviewed, although in these cases ESWL or expectant management was still pursued. Thus additional imaging with a KUB was required in order to confirm optimum management in 60 patients. CONCLUSION Additional plain radiography confers a significant advantage in the planning of treatment for urolithiasis once the diagnosis has been established by NCT because of information it provides regarding radio-opacity as well as stone size and visibility. This information cannot be delivered by NCT alone. We therefore recommend that KUB imaging is performed on all new stone patients referred for treatment.