Ultrasound diagnostics of rectal intussusception

AIM: analysis of dynamic transrectal ultrasound (TRUS) and dynamic transperineal ultrasound (TPUS) accuracy in rectal intussusception (RI) diagnosis. PATIENTS AND METHODS : a prospective cohort single-center diagnostic accuracy study of ultrasound for RI detection (January 2023 — October 2024) included 151 patients with obstructive defecation syndrome, without signs of complete rectal prolapse and without history of surgical treatment for pelvic floor descent syndrome. All patients underwent dynamic TRUS, dynamic TPUS and X-ray defecography. Ultrasound results were compared with X-ray defecography data. RESULTS : according to the X-ray defecography, RI was detected in 126/151 (83.4%) patients, according to dynamic TRUS — in 108/151 (71.5%), according to dynamic TPUS — in 110/151 (72.8%), according to complex dynamic ultrasound — in 124/151 (82.1%). The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of dynamic TRUS in RI detection were 82.5% (95% confidence interval (CI): 74.8–88.7), 84.0% (95% CI: 63.9–95.5), 96.3% (95% CI: 90.8–99.0), 48.8% (95% CI: 33.3–64.5) and 82.8% (95% CI: 75.8–88.4), respectively, dynamic TPUS — 81.7% (95% CI: 73.9–88.1), 72.0% (95% CI: 50.6–87.9), 93.6% (95% CI: 87.3–97.4), 43.9% (95% CI: 28.5–60.3) and 80.1% (95% CI: 72.9–86.2), complex dynamic US — 92.1% (95% CI: 85.9–96.1), 68.0% (95% CI: 46.5–85.1), 93.6% (95% CI: 89.1–96.3), 63.0% (95% CI: 46.95–76.6) and 88.1% (95% CI: 81.8–92.8), no statistically significant differences were found. CONCLUSION : ultrasound is a safe, highly sensitive method for RI detection in patients with obstructive defecation syndrome. Equivalent diagnostic accuracy of dynamic TRUS, dynamic TPUS and complex dynamic US allows using any available technique to detect RI. Complex dynamic US seems to be universal method for assessment the anatomical and functional state of rectum.