Correlations of anatomical parameters in dynamic pelvic CT and conventional defecography for patients with rectal prolapse.

PURPOSE To evaluate the correlations of anatomical parameters between dynamic pelvic CT (D-PCT) and conventional defecography (CD) for patients with rectal prolapse. MATERIAL AND METHODS 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. RESULT 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. CONCLUSION 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.