Radiographic techniques and interpretation of the acute abdomen

A clinical review of pathophysiology, diagnosis, and treatment of uroabdomen in the dog and cat

“…The rapid rise of intraperitoneal pressure caused by the traumatic event may cause rupture of a distended bladder with a thin wall and stretched muscle fibers . Male dogs are at an increased risk of bladder rupture because their long, narrow urethra cannot easily adapt to a rapid rise in intra‐vesicular pressure . Patients that incur pelvic fractures also have an increased likelihood of uroabdomen due to deformation of the pelvic canal in addition to laceration of the bladder or urethra from sharp bone fragments .…”

“…Survey radiography is limited as a sole diagnostic tool in animals with abdominal effusion due to limitations in serosal detail . Radiographic findings that increase the index of suspicion of urinary tract leakage include the presence of retroperitoneal or peritoneal effusion, inability to visualize the margins of the bladder, and pelvic fractures . Visibility of a urinary bladder does not exclude a small leak from the bladder or disruption of another portion of the urinary tract …”

“…Retrieval of urine does not rule out a ruptured bladder . The amount of contrast medium necessary to distend the urinary bladder is approximately 10 mL/kg, or until there is resistance of the syringe during infusion of contrast . Postcontrast radiographs are performed immediately following infusion to identify leakage of contrast medium, which will appear as an irregular pattern within the peritoneal cavity or outlining the intraperitoneal viscera .…”

“…If no contrast is noted, repeating the radiographs 5–10 minutes later may allow for smaller leaks to become visable. Important recommendations to ensure that the positive contrast cystogram is of diagnostic quality include making sure the colon is devoid of feces, the acquisition of orthogonal or oblique views if necessary, and achieving adequate distention of the urinary bladder with contrast medium …”

“…Radiographs are then taken to assess the integrity of the urethra. Diagnosis is obtained if there is visualization of contrast leakage into the peritoneal cavity or into the periurethral tissue . Leakage of contrast into the periurethral tissues with the presence of contrast medium reaching the urinary bladder is consistent with a partial urethral tear.…”