Renal pelvis density on preoperative ct: a novel predictor of infectious complications after percutaneous nephrolithotomy.

To investigate the association between infectious complications following percutaneous nephrolithotomy (PCNL) and renal pelvis urine density (RPUD) measured on preoperative non-contrast-enhanced computed tomography scans.This retrospective cohort study was conducted on patients who underwent PCNL between January 2020 and December 2024. Preoperative non-contrast-enhanced computed tomography was used to assess stone characteristics and RPUD measurement. Patients were categorized into infectious and non-infectious groups based on postoperative infectious complications. The groups were compared in terms of demographic data, stone characteristics (stone burden, localization, stone density), length of stay and RPUD.The study included 273 patients (76% male; 24% female). The median RPUD value was 13.1 ± 4.9 in the non-infectious group and 17.2 ± 4.6 in the infectious group (p < 0.001). Age, sex, BMI, ASA score, diabetes mellitus, stone side and localization were similar in both groups. In the multivariate analysis, stone density and RPUD were found to be associated with postoperative infectious complications (p = 0.034, p = 0.001, respectively). Postoperative infection risk increased 1.13-fold with each unit (HU) increase in RPUD. The cut-off value of RPUD value was 15.15 for predicting postoperative infection, with 66.6% sensitivity and 65.8% specificity (AUC: 0.702, 95% CI = 0.615-0.79, p < 0.001).This study demonstrated a significant association between higher preoperative RPUD values and the development of infectious complications following PCNL. RPUD-a simple measurement obtained from preoperative CT scans-may serve as an early indicator of infection risk and support prophylactic antibiotic planning or drainage decision-making.