Cine magnetic resonance urography as a new approach for postoperative evaluation of the reconstructed upper urinary tract: a multicenter study

PURPOSE: To evaluate the feasibility and usefulness of cine magnetic resonance urography (cine MRU) as a novel postoperative examination after upper urinary tract reconstruction surgery. METHODS: Ninety-six patients underwent cine MRU for postoperative evaluation between August 2015 and August 2020. The morphological observations included regular peristalsis, anastomosis, urine flow signals, and reflux. The quantitative evaluations included luminal diameter, peristaltic amplitude, contraction ratio, peristaltic waves, and ureteric jets. The surgical outcomes were classified as success, gray area, or failure by combining the results of cine MRU, symptoms, and the degree of hydronephrosis. RESULTS: There was no obvious stenosis of the anastomosis in 83 patients (86.46%). Regular peristalsis of the ureter and signals of urination was observed in 85 (88.54%) and 84 patients (87.50%), respectively. In addition, three patients (3.13%) showed urine reflux. The patients in both the success group and the gray area group showed significantly different creatinine levels (success 86.2 ± 22.3 μmol/L vs. failure 110.7 ± 8.2 μmol/L, P = 0.016; gray area 81.0 ± 20.0 μmol/L vs. failure 110.7 ± 8.2 μmol/L, P = 0.009) and estimated glomerular filtration rate (success: 88.5 ± 23.1 mL/min·1.73 m(2), failure: 61.6 ± 14.1 mL/min·1.73 m(2), P = 0.014; gray area: 94.7 ± 24.6 mL/min·1.73 m(2), failure: 61.6 ± 14.1 mL/min·1.73 m(2), P = 0.007) compared to those in the failure group. The ipsilateral split renal function was 33.6 ± 15.0, 24.5 ± 13.4, and 20.1 ± 0.4 mL/min in the success, gray area, and failure groups, respectively (P = 0.354). CONCLUSION: Cine MRU demonstrates the morphology and function of the reconstructed upper urinary tract. The results of cine MRU can be used to evaluate the surgical effect, providing guidance for further treatment.