Correlations of Anatomical Parameters in Dynamic Pelvic CT and Conventional Defecography for Patients with Rectal Prolapse

To evaluate the correlations of anatomical parameters between dynamic pelvic CT (D-PCT) and conventional defecography (CD) for patients with rectal prolapse.Anatomical parameters in multislice CT scanning of the pelvis performed at rest and during simulated defecation (D-PCT) were studied with those of CD to evaluate the correlations in both methods for 10 patients with rectal prolapse.The correlation coefficients of the pubococcygeal line and the pubosacral line were r=0.6 and r=0.8 respectively. The length from anal verge to pubococcygeal line and to the pubosacral line showed a good correlation of r=0.7. The length of puborectal muscle showed a good correlation of r=0.8. Anorectal angle was significantly well correlated between two methods (r=0.9, p<0.05). The lengths of anococcygeal length and anosacral length showed a good correlation.The anatomical parameters measured by D-PCT were well correlated with those by CD. D-PCT might be an alternative tool for anatomical evaluation of the anorectal region in patients with rectal prolapse.