Question

Evaluation of suspected bladder injury on CT.

Hint:

Use a CT cystogram with contrast for the most accurate assessment of bladder injury. Look for contrast extravasation to confirm the diagnosis of bladder rupture.

Answer 1

Step 1: Understanding Bladder Injury.
Bladder injuries are often caused by blunt or penetrating trauma, and they can result in urinary extravasation, peritoneal contamination, and sepsis. CT imaging is commonly used to assess suspected bladder injuries, particularly in the setting of trauma.

Step 2: Radiological Evaluation of Bladder Injury on CT.
1. CT with Contrast (CTC): A CT cystogram with contrast is the gold standard for evaluating bladder injury. The steps are as follows:
- Filling the bladder with contrast: The bladder is filled with a contrast agent (usually iodinated contrast), and a CT scan is performed.
- Bladder Wall Rupture: A bladder rupture is suggested when there is contrast extravasation outside the bladder, seen as contrast leakage into the peritoneum or retroperitoneal space.
- Intraperitoneal Rupture: Contrast material leaking into the peritoneal cavity suggests an intraperitoneal rupture. These injuries are more common and often associated with more severe trauma.
- Extraperitoneal Rupture: If the contrast leaks into the surrounding soft tissues but does not enter the peritoneal cavity, it indicates an extraperitoneal rupture. These are often managed non-surgically.

2. Non-Contrast CT: If contrast is not available or there is contraindication for its use, a non-contrast CT may show:
- Bladder wall thickening or distension, which can indicate injury.
- Pelvic fractures or other associated injuries that can suggest bladder trauma.

3. Other Features to Look for on CT:
- Hemoperitoneum or pelvic fluid collections may indicate bladder rupture.
- Pelvic fractures and bladder neck or urethral injury should also be considered.

Step 3: Conclusion.
CT imaging, particularly with contrast, is a valuable tool for diagnosing bladder injuries. The presence of contrast extravasation, especially into the peritoneum, is a strong indicator of bladder rupture. Timely imaging and intervention are essential to prevent complications and guide treatment.