Background

This study examines the correlation between magnetic resonance imaging (MRI)-derived volume parameters, surgical outcomes, and renal function in adults undergoing ureteropelvic junction (UPJ) obstruction surgery. Understanding these relationships can improve surgical planning, patient selection, and postoperative prognosis.

Purpose

To assess the correlation between anatomical parameters and surgical outcomes in adult patients with UPJ obstruction.

Material and Methods

A prospective cross-sectional study was conducted on 60 patients with UPJ obstruction, selected via simple random sampling. The hydronephrosis volume (HV) to renal volume (RV) ratio was calculated using MR urography (MRU). Preoperative diethylene triamine pentaacetic acid (DTPA) differential renal function (DRF) and creatinine levels were also recorded. Patients requiring surgery were followed up after 6 months, measuring pelvis/RV ratio, creatinine, and DTPA DRF. Statistical analyses were performed to find correlations.

Results

Operated patients had a higher preoperative HV/RV ratio (AUC=0.914, 95% confidence interval [CI]=0.829–1.000; P <0.001) and higher DTPA DRF values (AUC=0.936, 95% CI=0.860–1.000; P <0.001). Patients with greater preoperative HV/RV ratios were less likely to achieve anatomical normalization. Significant correlations were found between HV/RV ratios with DTPA DRF and creatinine (P <0.05). DeLong’s test showed no significant differences between HV/RV ratios and DTPA DRF in predicting surgical need.

Conclusion

Quantitative volumetric analysis using MRU can effectively predict the need for surgery and renal function deterioration in patients with UPJ obstruction. The HV/RV ratio plays a crucial role in guiding surgical decisions and predicting outcomes. This study emphasizes and tests the hypothesis that higher degree of hydronephrosis correlates with higher degree of deterioration of renal function and need for surgical intervention.