Imaging techniques for the diagnosis of male traumatic urethral strictures

Urethral injures, pelvic trauma, and certain congential abnormalities in male can often cause urethral strictures and scarring. Adequate and accurate imaging diagnosis of urethral strictures is critial to select a surgical approach. Although urethrography is commonly used in evaluating male urethral injury and strictures, its limitation is that the contrast offers images only at the urethral lumen but not of the periurethral structures. Sonourethrography (SUG) has the ability to define the periurethral tissues and without the radiation exposure, the degree of periurethral fibrosis can be shown with a view to guiding surgery especially in bulbar urethra. Computed tomography (CT) urethrography has the advantage of examining patients only in one position, and by generating three-dimensional images; it can accurately measure the stricture length. Magnetic resonance imaging (MRI) provide useful information in certain clinical situations, particularly posterior urethral trauma and in the evaluation of the periurethral soft tissues. However, both CT and MRI are relative high cost. The selection of imaging methods should depend on the etiology, sites, patient's general condition and the type of urethral injury, using a rational combination of different imaging methods can improve the accuracy of diagnosis for traumatic urethral strictures.