Introduction

Computed tomographic excretory urography (CTEU) is the imaging modality of choice for the detection of ectopic ureters in both people and dogs. Recently, differentiation of intramural and extramural ureteral ectopia has become an important preoperative distinction to make, as less invasive cystoscopic laser ablation of intramural ectopic ureters has been recommended.

Objective

To describe the morphologic and morphometric CTEU features of intramural ectopic ureters in dogs, which is the first step in determining if CTEU can differentiate intramural and extramural ureteral ectopia.

Methods

This retrospective study evaluated CTEU images of dogs with surgical and/or cystoscopically confirmed intramural ectopic ureters. All studies were independently reviewed by two board-certified veterinary radiologists for the presence of ureteral ectopia, ureteral dilatation, ureteral tortuosity, a normal ureterovesical junction and ureteral orifice location.

Results

Ten dogs met the inclusion criteria with 14 intramural ectopic ureters identified at surgery/cystoscopy. Reviewers correctly identified 14/14 ectopic ureters. CTEU changes identified included ureteral dilatation (7), ureteral tortuosity (3), lack of a normal ureterovesical junction (14), urethral ureteral orifice location (14) and lack of ureteral divergence (14).

Conclusion

Common CTEU findings in dogs with intramural ectopic ureters include: lack of a normal ureterovesical junction, a urethral ureteral orifice location, and lack of ureteral divergence. Further investigation is needed to determine if these CTEU findings may allow differentiation of intramural and extramural ectopic ureters in dogs.