What imaging should I order for a patient with hematuria and a Foley (urinary) catheter?

Imaging for Hematuria in a Patient with a Foley Catheter

For a patient with hematuria and a Foley catheter, retrograde cystography (either plain film or CT) is the recommended imaging study to evaluate for possible bladder injury. 1

Rationale for Retrograde Cystography

Hematuria in a patient with a Foley catheter raises concern for potential bladder injury, which requires proper evaluation to prevent serious complications:

• Retrograde cystography is the technique of choice to diagnose bladder injury with high accuracy
• Both plain film and CT cystography have similar specificity and sensitivity for detecting bladder rupture 1

Proper Technique for Retrograde Cystography

The technique must be performed correctly to ensure diagnostic accuracy:

• Retrograde, gravity filling of the bladder with contrast material
• Minimum volume of 300 mL or until patient reaches tolerance to maximize bladder distention
• At least two views required:
  • First view at maximal fill
  • Second view after bladder drainage
• Additional oblique views may provide more information but aren't required 1

CT Cystography Technique

If choosing CT cystography:

• Use dilute water-soluble contrast to prevent artifacts
• Follow the same principles of adequate bladder distention
• Important pitfall to avoid: Simply clamping the Foley catheter to allow excreted IV contrast to accumulate in the bladder is NOT appropriate and will result in missed bladder injuries due to inadequate distention 1

Clinical Considerations

The choice between plain film and CT cystography depends on:

• Equipment availability
• Imaging requirements for other associated injuries
• Patient stability
• Ease of testing 1

Management Based on Findings

The management will depend on the type of bladder injury detected:

• Intraperitoneal bladder ruptures require surgical repair to prevent peritonitis, sepsis, and other serious complications 1
• Uncomplicated extraperitoneal bladder injuries can typically be managed with catheter drainage 1

Important Caveats

1. The presence of a Foley catheter itself can cause minimal hematuria (typically fewer than four red blood cells per high-power field), but significant hematuria should not be attributed to catheterization alone 2

2. Hematuria with a Foley catheter in place may indicate:

   • Traumatic catheter insertion
   • Bladder injury
   • Other urologic pathology requiring evaluation

3. If the patient has a history of pelvic trauma, the risk of bladder rupture is significantly higher, making imaging even more critical 1