The posterior urethra is best visualized by -

Voiding cystourethrography is the best method to visualize posterior urethra. Remember, Urethra can be imaged radiographically in two ways. Anterograde techniques → Best for visualization of posterior urethra. (This is done along with voiding cystourethrography or with voiding following excretory urography) Retrograde technique → Best for examining the anterior (penile) urethra ​(Contrast is injected through tip of urethra).