Can ultrasound replace the intravenous urogram in preliminary investigation of renal tract disease? A prospective study.

The intravenous urogram has long been the mainstay of urinary tract imaging in adult practice. It has been shown recently that in many clinical situations the routine use of intravenous urography is no longer justified and in some situations avoidance of adverse contrast reactions, reduced examination time and significant cost reduction. In order to assess the clinical and financial aspects of a change in practice in our department, a prospective study was undertaken over a total of 10 weeks when 328 patients who were referred for intravenous urography were also examined independently by ultrasound combined with the plain abdominal radiograph. The results were compared and in 81.4% of cases the two techniques yielded identical information. Ultrasound plus a plain abdominal radiograph provided more diagnostic information in a further 12.5% of cases, whilst intravenous urography was more informative in only 6.1%. The findings of the study are discussed by considering the main clinical groups and comparing the relative yields of ultrasound and urography. A scheme of routine urinary tract investigations using ultrasound and the plain abdominal radiograph is proposed. We estimate a 58% reduction in number of urographic examinations while retaining diagnostic accuracy. The financial and planning implications for our department are discussed.