Three-Dimensional Computerized Model Based on the Sonourethrogram: A Novel Technique to Evaluate Anterior Urethral Stricture.

PURPOSE: The sonourethrogram is a useful alternative to the traditional retrograde urethrogram to evaluate anterior urethral strictures. With the development of 3-dimensional reconstructive techniques 3-dimensional urethral imaging can provide more accurate and useful information to enable the surgeon to make the best surgical decisions. We evaluated the accuracy and efficacy of a 3-dimensional reconstructed digital model of the urethra based on the sonourethrogram to assess anterior urethral disease.

MATERIALS AND METHODS: A total of 50 patients with an anterior urethral stricture and 10 healthy volunteers were enrolled in this study from April 2014 to January 2017. All patients and volunteers underwent sonourethrogram and retrograde urethrogram. Three-dimensional urethral models were reconstructed based on the sonourethrogram. Stricture length and location on retrograde urethrogram or sonourethrogram based images were compared with those found at operation.

RESULTS: The 3-dimensional digital model revealed the entire anterior urethra, including the navicular fossa, and the penile and bulbar parts. The semitransparent model clearly demonstrated the structure of the corpus spongiosum and inside the urethral lumen. Further information on spongiofibrosis could also be seen in the 3-dimensional digital model. There was no significant difference in stricture length or location in the 3-dimensional model compared with retrograde urethrogram imaging and actual surgical findings. However, the latest technique could only reconstruct the short segment of the anterior urethra due to the probe width limitation.

CONCLUSIONS: The 3-dimensional computerized model based on the sonourethrogram is a novel and effective technique of evaluating anterior urethral strictures.