MR urography using HASTE imaging in the assessment of ureteric obstruction

OBJECTIVE. The purpose of this study was to evaluate an MR sequence using half-Fourier acquisition single-shot turbo spin-echo (HASTE) imaging in the assessment of ureteric obstruction. SUBJECTS AND METHODS. We prospectively evaluated 111 kidneys in 56 consecutive patients with HASTE MR urography and compared that imaging technique with excretory urography. The HASTE sequence was used to acquire images in the axial, sagittal, and coronal planes while patients held their breath. Level of obstruction and ureteric diameter were assessed, and the time required to determine the level of obstruction by both techniques was noted. RESULTS. With HASTE MR urography, we correctly diagnosed obstruction in 41 (100%) of 41 kidneys. Of the obstructed kidneys in which the ureter was shown by both excretory urography and MR urography, agreement was high (κ= .642) between the two imaging techniques regarding the level of obstruction. HASTE MR urography showed perirenal fluid in 20 (87%) of 23 acutely obstructed kidneys. HASTE MR urography showed the site of obstruction on the first 13-sec scan in 33 (80%) of 41 kidneys. CONCLUSION. HASTE MR urography accurately and rapidly shows the level and degree of ureteric obstruction. It can be used to differentiate between acute and chronic obstruction on the basis of its ability to show perirenal fluid.