THE VALUE OF MR UROGRAPHY THAT USES HASTE SEQUENCES TO REVEAL URINARY-TRACT DISORDERS

OBJECTIVE. Breath-hold MR urography using half-Fourier acquisition sin gle-shot turbo spin-echo (HASTE) sequences was evaluated as a noninvas ive alternative to excretory urography in healthy volunteers and in pa tients with disorders of the urinary tract. SUBJECTS AND METHODS. Twen ty healthy volunteers and 45 patients with disorders of the urinary tr act underwent HASTE MR urography on a 1.5-T MR imaging unit. Imaging t ime was 2 sec for single-thick-slice (20- to 60-mm slice thickness) te chnique and 10-18 sec for multislice technique. In the latter, images were postprocessed with maximum-intensity-projection technique and vis ualized in an arbitrary plane. Obstruction and its level were determin ed solely by excretory urography in eight patients, by excretory urogr aphy, with other imaging techniques (CT, retrograde pyelography, or so nography) in 27 patients, and by sonography alone in the 20 normal vol unteers, seven pregnant women, and three patients who were allergic to iodinated contrast media. We evaluated whether HASTE MR urograms show ed obstruction, showed the level of obstruction, and showed the cause of obstruction. RESULTS. In all 20 healthy volunteers and all 45 patie nts, the upper, middle, and lower group of renal calices and the pelvi s were clearly revealed by HASTE MR urography. In patients whose urina ry tracts were seen on excretory urography (n = 31), the accuracy of H ASTE MR urography in revealing urinary tract dilatation and level of o bstruction completely correlated with that of excretory urography, alt hough functional information about the obstructed collecting system wa s not obtained. However, MR urography revealed nonfunctioning urinary tracts that were invisible on excretory urography (n = 6). In patients with extrinsic obstruction (n = 27), MR urography also revealed the o bstructing lesions. Small stones within the ureter were more clearly s een on single-shot or source images. With HASTE MR urography, hydronep hrosis in pregnant women (n = 7) was clearly shown. CONCLUSION. HASTE MR urography can be used as an alternative to excretory urography to o btain high-quality images of the dilated urinary tract and adjacent ab normalities. HASTE MR urography allows rapid acquisition of images, th us overcoming the drawbacks of earlier MR urography techniques.