Abstract: Objective To assess the diagnostic value of CT peritoneography for continuous ambulatory peritoneal dialysis-related hydrothorax. Methods We sequentially recruited patients who were treated with continuous ambulatory peritoneal dialysis (CAPD) and had the complication of hydrothorax during Dec. 2015 to May 2016 in our hospital. Using Philips Brilliance Plus 64 CT scanner, conventional CT scans on thorax and upper abdomen were first performed, and then 50 mL non-ionic contrast medium (Iopamidol) mixed with 2L dialysate were infused into peritoneal cavity via Tenchkoff catheter. CT scans on thorax and upper abdomen were repeated after the infusion for 30 minutes. Images were compared before and after the infusion. The differences in 24h urine volume and ultrafiltration volume before and after CT Peritoneography were compared using paired t test. Results Eighteen out of the 225 follow- up cases were successfully enrolled into this study. Abnormal findings were found in 3 cases, including pleuraperitonum communication (2 cases) and peritonum-mediastinum leakage (one case). There was no statistically differences in 24h urine volume and ultrafiltration volume before and after CT Peritoneography (t= 0.674, P=0.509 for 24h urine volume; t=1.212, P=0.242 for ultrafiltration volume). Conclusion CT peritoneography can provide us with accurate diagnosis of CAPD-related hydrothorax, and reveal anatomical abnormalities regarding location and size, valuable for the pathogenesis and treatment of hydrothorax in CAPD patients.

Key words: X-ray computed tomography, peritoneography, continuous ambulatory peritoneal dialysis, hydrothorax