Can computed tomography--assisted virtual endoscopy be an innovative tool for detecting urethral tissue pathologies?

ABSTRACT

OBJECTIVE: To test if virtual endoscopy (VE) enabled by 3-dimensional computed tomographic (CT) scanner with supporting software allows for practical clinical interrogation and evaluation of the urethral lumen and anatomy in an animal model. METHODS: Assessment of urethral anatomy and repair results was performed in 18 male beagles using conventional retrograde urethrography, CT-assisted retrograde urethography, and voiding urethrocystography. The image slices from these studies were processed using TeraRecon software to create a virtual representation of the urethra and compared with conventional urethrography and postmortem analysis of retrieved urethras for diagnostic assessment and correlation. RESULTS: CT-assisted VE showed the orientation, size, and gross morphology of urethral anatomy, including the lesions in all the 18 animals studied. The VE showed patent urethra in 12 dogs, stenosed urethra in 3 dogs, urethral diverticulum with stricture in 2 animals, and fistula in one. These findings correlated with those of conventional diagnostic methods. The findings of the voiding and retrograde virtual urethrocystoscopy studies were also comparable. CONCLUSION: These results demonstrate that CT-assisted VE is able to identify the anatomic landmarks in an animal model. This allows for detection of the site of different pathologies and their relations to important structures such as urethral sphincters and the bladder neck. Digital imaging might be used to identify urethral pathologies with greater details and characterization of the lesions when compared with the conventional urethrocystography.