Can a computed tomography (CT) scan with contrast of the prostate show the renal system in cases of gross hematuria?

CT with Contrast of the Prostate Can Show the Renal System in Cases of Gross Hematuria

Yes, a CT scan with contrast of the prostate can effectively show the renal system in cases of gross hematuria, as CT urography (CTU) is the recommended imaging modality for comprehensive evaluation of the entire urinary tract in patients with gross hematuria. 1

Optimal Imaging Protocol for Gross Hematuria

CT Urography (CTU) Components

CTU is specifically designed to evaluate the entire urinary tract and includes:

• Unenhanced (pre-contrast) phase: Optimal for detecting urinary calculi, a common cause of hematuria
• Nephrographic phase: Best for visualizing renal parenchymal abnormalities and masses
• Excretory phase: Shows the collecting systems, ureters, and bladder distended with contrast material 1, 2

This comprehensive protocol allows evaluation of the entire urinary tract from kidneys to bladder in a single examination, making it superior to other imaging modalities for gross hematuria evaluation.

Why CTU is Superior for Gross Hematuria

• High sensitivity (87%) and specificity (99%) for detecting bladder malignancy 1
• Excellent for detecting upper tract tumors (0.8% rate in gross hematuria) 1
• Comprehensive evaluation of both nephrogenic and urogenic causes of hematuria 2
• Can detect renal masses, urothelial lesions, calculi, and other potential causes in one examination 3

Clinical Considerations

Advantages of CT with Contrast for Prostate/Renal Imaging

1. Comprehensive coverage: When imaging the prostate with contrast, the scan typically includes the entire abdomen and pelvis, which encompasses the kidneys, ureters, and bladder
2. Diagnostic efficiency: A single examination can evaluate multiple potential sources of hematuria
3. Superior detection: Better visualization of small lesions compared to ultrasound or non-contrast studies 1

Limitations and Caveats

• Radiation exposure is a consideration, especially in younger patients
• Contrast administration requires adequate renal function
• For patients with renal insufficiency or contrast allergy, MR urography is an alternative 4

Special Populations

Young Adults with Hematuria

For patients ≤40 years without predisposing conditions, an unenhanced CT alone may be sufficient as:

• 94.8% of clinically significant findings are visible on unenhanced images
• Most common findings are renal or ureteral calculi (75.3% of significant findings)
• This approach reduces radiation exposure in this radiosensitive population 5

Patients with Contraindications to Contrast

Alternative imaging options include:

• MR urography for patients with renal insufficiency or contrast allergy 4
• Ultrasound as an initial screening tool, though it has limited sensitivity (35.3-50.7%) compared to CT 1

Summary of Imaging Recommendations for Gross Hematuria

The American College of Radiology Appropriateness Criteria clearly states that "CTU without and with IV contrast or MRU without and with IV contrast is usually appropriate for the initial imaging of gross hematuria." 1

When performing a CT of the prostate with contrast in a patient with gross hematuria, ensuring that the protocol includes the key components of CTU (unenhanced, nephrographic, and excretory phases) will provide optimal visualization of the entire urinary tract and maximize diagnostic yield.