MR imaging of renal collecting system with gadoxetate disodium: Feasibility for MR urography

Purpose To determine the feasibility of using gadoxetate disodium for MR urography. Materials and Methods We retrospectively reviewed 50 consecutive gadoxetate disodium-enhanced abdominal MRI examinations meeting inclusion criteria. For each examination, 30 min postcontrast hepatobiliary phase sequences were reviewed to assess bilateral collecting system segments, including upper pole, interpolar, and lower pole calyces; renal pelvis; and proximal one-third of ureter. Each segment was assessed for degree of opacification (none, <50%, ≥50%, complete) and susceptibility artifact (none, partial thin rim, thick/complete rim, total obscuration). Opacification and susceptibility scores were also calculated for each examination. Results The 50 reviewed examinations were performed on 46 patients (26 women, 20 men; mean age, 57 years) and included a total of 1000 segments. Of these, 808 (80.8%) were opacified completely, 103 (10.3%) were opacified ≥50%, 39 (3.9%) were opacified <50%, and 50 (5.0%) were not opacified. Of 1000 segments, no susceptibility artifact was present in 822 (82.2%), while a partial thin rim was present in 113 (11.3%), a thick/complete rim in 64 (6.4%) and total obscuration in 1 (0.1%). Conclusion Gadoxetate disodium contrast produced a high degree of opacification of the proximal urinary collecting system with low incidence of susceptibility artifact; therefore, it is a feasible contrast agent for MR urography.