Early report: Comparison of breath-hold MR excretory urography, Doppler ultrasound and isotope renography in evaluation of symptomatic hydronephrosisin pregnancy

AIM: To compare assessment by MR excretory urography (MREU), Doppler ultras ound and isotope renography of women with symptomatic hydronephrosis in pre gnancy and to define its cause. MATERIALS AND METHODS: Eleven women at 19-34 weeks of gestation were studie d prospectively with gadolinium-enhanced breath-hold gradient echo MREU and transabdominal Doppler ultrasound compared with a 'gold standard' of isoto pe renography employing frusemide challenge. All studies were performed wit hin 24h, were reported independently in a blinded fashion and employed clea rly defined criteria. Obstetric and infant outcomes were obtained, RESULTS: There were no adverse reactions to gadolinium administration in pr egnancy and no adverse obstetric or infant outcomes. Three of the 11 women were unable to tolerate the complete MREU protocol. Ultrasound indices coul d not be used to predict ureteric obstruction as shown by; isotope renograp hy, MREU agreed with renographic findings in five of the six cases with obs truction and in two without obstruction. MREU directly demonstrated hydrone phrosis to result from extrinsic compression of the ureter between the grav id uterus and iliopsoas muscle, CONCLUSION: MR excretory urography is a promising technique which affords e quivalent functional and additional anatomical information to isotope renog raphy, It is more accurate than Doppler ultrasound in the assessment of ure teric obstruction in pregnancy. (C) 2000 The Royal College or Radiologists.