When is a CT (Computed Tomography) program with or without contrast indicated for patients presenting with hematuria (blood in urine)?

CT Protocol for Hematuria Evaluation

For patients presenting with hematuria, CT urography (CTU) without and with IV contrast is the recommended imaging approach for adults with gross hematuria or those with risk factors, while ultrasound is appropriate as first-line imaging in children and in specific adult scenarios. 1

Adult Patients

Gross Hematuria

• CTU without and with IV contrast is usually appropriate as the initial imaging test due to the high risk of upper tract tumors (0.8%) 1
• CTU has demonstrated high diagnostic accuracy with sensitivity of 87%, specificity of 99%, positive predictive value of 91%, and negative predictive value of 98% for detecting bladder malignancy 1
• MRU without and with IV contrast is an appropriate alternative when CT is contraindicated 1
• Cystoscopy remains essential for complete evaluation, as bladder cancer is the most common malignancy detected in patients with hematuria 2

Microscopic Hematuria

• For patients with risk factors (smoking history, occupational exposures, family history of urologic malignancies, history of pelvic radiation):

  • CTU without and with IV contrast is usually appropriate 1
  • CTU has shown superior detection of urothelial malignancy with pooled sensitivity of 96% and specificity of 99% 1

• For patients without risk factors or with benign causes (recent vigorous exercise, infection, viral illness, menstruation):

  • CT abdomen and pelvis without IV contrast may be appropriate 1
  • Unenhanced CT alone may be sufficient in young adults without predisposing conditions, reducing radiation exposure 3

• For pregnant patients:

  • Ultrasound of kidneys and bladder is usually appropriate 1

Pediatric Patients

Non-traumatic Hematuria

• For nonpainful, nontraumatic isolated microscopic hematuria without proteinuria:

  • Imaging is usually not appropriate 1

• For nonpainful, nontraumatic isolated microscopic hematuria with proteinuria:

  • Ultrasound of kidneys and bladder is usually appropriate 1

• For nonpainful, nontraumatic isolated macroscopic hematuria:

  • Ultrasound of kidneys and bladder is usually appropriate 1

• For painful, nontraumatic hematuria with suspected urolithiasis:

  • Either ultrasound of kidneys and bladder or CT abdomen and pelvis without IV contrast is appropriate 1

Traumatic Hematuria

• For macroscopic hematuria with trauma:

  • CT abdomen and pelvis with IV contrast is usually appropriate 1
  • If renal injury is detected, delayed scans should be obtained to evaluate for collecting system disruption 1

• For microscopic hematuria with trauma:

  • CT abdomen and pelvis with IV contrast is appropriate in specific scenarios: congenital renal abnormalities, multiorgan injury, history of deceleration injury, localized flank pain, or flank ecchymosis 1
  • Patients with microscopic hematuria and pelvic fractures should undergo CT cystography to evaluate for bladder injury 1

Clinical Considerations and Pitfalls

• The diagnostic yield of CT urography varies significantly:

  • In young adults with hematuria, clinically significant findings are detected in approximately 22% of cases 3
  • In patients with visible hematuria, abnormalities are found more frequently than in those with non-visible hematuria (48% vs. 29%) 4

• Contrast considerations:

  • Enhanced CT with IV contrast is necessary for comprehensive evaluation of the urinary tract, especially for detecting urothelial malignancies 1
  • In young adults without predisposing conditions, unenhanced CT may be sufficient for initial evaluation, detecting up to 94.8% of clinically significant findings 3

• For suspected urethral injury (blood at urethral meatus, pelvic fractures, straddle injury):

  • Retrograde urethrography should be performed before bladder catheter placement 1

• Ultrasound limitations:

  • While useful as a screening tool, ultrasound has lower sensitivity for detecting renal injuries and urothelial lesions compared to CT 1
  • Diagnostic accuracy for bladder tumor detection with ultrasound ranges from 35.3-50.7% sensitivity and 89.9-99.3% specificity 1