Static-dynamic MR urography. Comparison with excretory urography and scintigraphy in experimentally induced urinary tract obstruction (UTO)

Purpose: To assess the diagnostic value of combined static-dynamic MR urogr aphy (MRU) for the functional-morphological evaluation of experimentally in duced urinary tract obstruction. Methods: Static-dynamic MRU - combination study with a respiratory-triggere d 3D-IR-TSE sequence and a dynamic 2D-FFE sequence after Gd-DTPA and furose mide - was obtained in comparison with Tc-99m-MAG3 diuretic renal scintigra phy (DRS), excretory urography (EU) and ultrasound (US) in 29 healthy pigle ts and in 20 piglets with surgically induced ureteric stenosis (total of 50 postoperative examination blocks). Results: MRU allowed complete depiction of the urinary tract in all control s, in operated piglets the stenosis was always correctly identified. Qualit y of MRU was superior to EU in 36 of 43 comparative studies. Calculation of single kidney function from parenchymal renograms, and assessment of urina ry excretion from whole-kidney renograms resulted in a highly significant a greement of MRU with DRS. Conclusion: Static-dynamic MR urography allows excellent depiction of exper imentally induced urinary tract obstruction, and reliable assessment of ind ividual renal function and urinary excretion. Two advantages of the method stand out, it does not require radiation and it permits a functional-morpho logical correlation.