MR Urography Using HASTE Imaging: Comparison with Intravenous Urography

Abstract

Purpose : To evaluate the usefulness of MR urography(MRU) using Half-Fourier acquisition single-shot turbospin-echo(HASTE) sequence compared with conventional intravenous urography(IVU). Materials and Methods : Thirtyfive lesions of 32 patients who underwent MRU because of delayed excretion or nonvisualization of the ureter wereincluded in this study. HASTE MR urography was performed with a 1.0 MR imaging unit. Coronal images includingthose of the kidney, ureter and bladder were obtained in every pa-tient using the multislice technique, and werepostprocessed by means of the maximal intensity projection technique. Scan time was 17-19 seconds. We analyzed theresults of MRU, focusing on level of obstruction, in-cidence of stone, ureter dilatation, and motion artifact, andin each case compared MRU findings with those of IVU. Results : In 12 of 35 lesions(34.2%), MRU more effectivelydiagnosed causes of obstruction than did IVU, while in seven lesions(20%), MRU and IVU were similar. In eightlesions(22.9%), all of which were caused by a stone, IVU was better than MRU, and in a further eight, neithermodality was able to diagnose the cause. For diagnosis of the level of obstruction, MRU was better than IVU in 20of 35 lesions(57.1%), and similar to IVU in seven(20%). In three lesions(8.6%), neither modality was able todetect the level of obstruction. Four lesions not related to obstruction were polycystic renal disease, cysticrenal change, vesicovaginal fistula and extra-re-nal pelvis. Dilatation of the ureter was seen in 23lesions(65.8%) on MRU and in seven lesions on IVU. Thus, MRU revealed dilatation of for the ureter more efectivelythan IVU. Conclusion : MRU using HASTE was valuable for the detection of underlying causes and levels ofobstruction in the urinary tract, and of abnormalities in surrounding structures in patients withnon-visualization of the kidney or delayed contrast excretion of the ureter, as seen on delayed IVU urogram.