Radiology of the bladder and urethra in blunt pelvic trauma.

Appropriate radiologic studies are mandatory for assessing the extent and nature of lower urinary tract injuries following blunt pelvic trauma. A flow sheet summarizing these radiographic studies is presented in Figure 24. With pelvic fracture, two injuries may be found--extraperitoneal rupture of the bladder and rupture of the posterior urethra. In some patients, these injuries may be combined. Intraperitoneal rupture of the bladder occurs as a result of a blow to the lower abdomen or pelvis in patients whose urinary bladder is distended at the time of injury. A pelvic fracture may or may not be present. Anterior urethral injuries are more commonly associated with instrumentation in the male patient; they may, however, occur as a result of blunt injury to the external genitalia or perineum.