Imaging assessment of uncomplicated bladder outflow obstruction.

To assess the impact of the use of plain X-ray films and ultrasound examinations on clinical decision-making in patients referred with symptoms of bladder outflow obstruction. Patients with symptoms of bladder outflow obstruction were recruited prospectively. After clinical assessment they underwent standard investigations of plain X-ray of the kidneys, ureters and bladder, and upper and lower urinary tract ultrasound. A management decision was made on the basis of all results. These decisions were then reviewed with specific reference to radiological findings to assess the role of imaging in the decision-making process. A total of 320 men were recruited for the study. X-ray of the kidneys, ureters and bladder detected 10 upper tract calculi, none of which has required active intervention to date. Four bladder calculi were detected. Two of these were also seen on ultrasound scan: one was small and insignificant, the other had caused microscopic haematuria, necessitating cystoscopy regardless of the X-ray findings. Upper tract ultrasound revealed abnormalities and anatomical variants which did not affect management. Four patients had upper tract dilatation but these had already had surgery planned on the basis of other investigations, including residual urine volume determination by lower tract ultrasound. Lower urinary tract ultrasound should be the only routine imaging used in the initial assessment of patients with bladder outflow obstruction, with consequent implications of reduced patient stress and reduced investigation cost.