Low dose low osmolar intravenous urography.

A prospective double blind randomised trial using 25 ml of Hexabrix 320 (ioxaglate, May and Baker), Niopam 370 (iopamidol, Merck) or Omnipaque 350 (iohexol, Nycomed) intravenous urography was carried out. The results showed no perceptible difference in the diagnostic quality of urograms with each of the media. An additional 25 ml of contrast medium was required by 4% of patients in order to obtain a satisfactory examination. We recommend that a dose of 25 ml of low-osmolar medium be used for all patients with the exception of the obese, those taking diuretics or those who have renal impairment.