What is the recommended initial imaging evaluation for a patient presenting with hematuria, considering their overall health status and potential underlying causes?

Imaging for Hematuria

For adults with confirmed hematuria (≥3 RBCs/HPF), multiphasic CT urography is the preferred initial imaging modality to detect malignancy, stones, and upper tract pathology, with mandatory cystoscopy to complete the evaluation. 1, 2

Confirm True Hematuria Before Imaging

• Verify dipstick-positive results with microscopic urinalysis showing ≥3 RBCs per high-power field on at least two of three properly collected clean-catch midstream specimens before ordering any imaging. 1
• Dipstick testing has only 65-99% specificity and produces false positives from myoglobin, hemoglobin, concentrated urine, or menstrual contamination. 1
• Do not initiate imaging workup for 0-2 RBCs/HPF, as this falls within normal range. 1

Risk Stratification Determines Imaging Urgency

High-Risk Patients (Require Immediate Complete Evaluation)

• Males ≥60 years or females ≥60 years 1, 2
• Smoking history >30 pack-years 1, 3
• Any history of gross hematuria (30-40% malignancy risk) 1, 3
• Occupational exposure to benzenes, aromatic amines, or chemical dyes 1, 2
• >25 RBCs/HPF on urinalysis 1, 3
• Irritative voiding symptoms without infection 1

Intermediate-Risk Patients

• Males 40-59 years or females ≥60 years 1, 3
• Smoking history 10-30 pack-years 1, 3
• 11-25 RBCs/HPF 1, 3

Low-Risk Patients

• Males <40 years and females <60 years 1, 3
• Never smokers or <10 pack-years 1, 3
• 3-10 RBCs/HPF 1, 3

Exclude Glomerular Disease Before Urologic Imaging

Before proceeding with urologic imaging, assess for glomerular disease indicators that would require nephrology referral in addition to (not instead of) urologic evaluation: 1, 2

• Tea-colored or cola-colored urine suggests glomerular bleeding 1
• Significant proteinuria (protein-to-creatinine ratio >0.3 or >300 mg/day) 1, 3
• Dysmorphic RBCs >80% on phase-contrast microscopy or red blood cell casts (pathognomonic for glomerular disease) 1, 3
• Elevated serum creatinine or declining renal function 1, 3

Critical caveat: The presence of glomerular features does NOT eliminate the need for urologic evaluation—malignancy can coexist with medical renal disease, and both evaluations must be completed. 1

Recommended Imaging by Clinical Scenario

Adult Gross Hematuria (Any Age)

Multiphasic CT urography is mandatory 1, 4, 5:

• Unenhanced phase (detects stones) 1
• Nephrographic phase (evaluates renal parenchyma for masses) 1
• Excretory phase (assesses collecting systems, ureters, bladder for urothelial tumors) 1
• Plus mandatory flexible cystoscopy to visualize bladder mucosa, urethra, and ureteral orifices 1, 2
• Sensitivity 92%, specificity 93% for detecting urologic pathology 5

Never ignore gross hematuria even if self-limited—30-40% malignancy risk mandates urgent urologic referral regardless of whether bleeding resolves. 1, 3

Adult Microscopic Hematuria (High-Risk)

Same complete evaluation as gross hematuria: 1, 2

• Multiphasic CT urography 1, 2
• Flexible cystoscopy 1, 2
• Consider voided urine cytology in very high-risk patients (age >80 years, heavy smoking, chemical exposure) 1

Adult Microscopic Hematuria (Intermediate-Risk)

• Multiphasic CT urography preferred 1
• Flexible cystoscopy recommended 1
• Shared decision-making may be appropriate, but err toward complete evaluation given cancer detection benefits 2

Adult Microscopic Hematuria (Low-Risk)

• Renal and bladder ultrasound may be appropriate initial imaging only for truly low-risk patients 1
• However, ultrasound detects only 75% of urinary tract stones and only 38% of ureteral stones 1
• If hematuria persists after negative ultrasound, proceed to CT urography 1
• Cystoscopy still required even when ultrasound is initial imaging choice 1

Pediatric Patients

Isolated microscopic hematuria without proteinuria, dysmorphic RBCs, or concerning features: 1, 3

• No imaging indicated initially—clinical follow-up only 1, 3
• Children are unlikely to have clinically significant renal disease in this scenario 1, 3

Gross hematuria in children: 1, 3

• Renal and bladder ultrasound is first-line imaging to exclude nephrolithiasis, anatomic abnormalities, and rarely tumors 1, 3
• CT is NOT appropriate for initial evaluation of isolated nonpainful, nontraumatic hematuria in children 1, 3

Traumatic hematuria in children: 3

• CT with IV contrast if concerning mechanism, multiorgan injury, deceleration injury, flank pain/ecchymosis, or known congenital renal abnormalities—even with only microscopic hematuria 3

Alternative Imaging When CT Contraindicated

If CT urography cannot be performed due to renal insufficiency or contrast allergy: 1

• MR urography is the preferred alternative 1
• Renal ultrasound plus retrograde pyelography is acceptable but less optimal 1, 4
• Traditional intravenous urography (IVU) remains acceptable but has limited sensitivity for small renal masses 1, 4

Critical Pitfalls to Avoid

• Never attribute hematuria to anticoagulation or antiplatelet therapy—these medications may unmask underlying pathology but do not cause hematuria, and full evaluation must proceed regardless. 1, 3
• Never delay urologic evaluation for suspected UTI in high-risk patients—obtain urine culture before antibiotics, but if hematuria persists beyond 2 months despite appropriate antibiotic therapy, this effectively rules out simple infection and mandates complete urologic workup. 1
• Do not rely on ultrasound alone for complete hematuria evaluation in adults—it misses significant pathology including stones and urothelial tumors. 1
• Do not use urine cytology or molecular markers (NMP22, BTA stat) in initial evaluation of asymptomatic microscopic hematuria—these are not recommended by current guidelines. 1, 3
• Benign prostatic hyperplasia can cause hematuria but does not exclude concurrent malignancy—gross hematuria from BPH must be proven through appropriate evaluation, not assumed. 1

Follow-Up Protocol for Negative Initial Evaluation

If complete workup (CT urography + cystoscopy) is negative but hematuria persists: 1

• Repeat urinalysis at 6,12,24, and 36 months with blood pressure monitoring at each visit 1
• After two consecutive negative annual urinalyses, no further testing for asymptomatic microhematuria is necessary 1
• Immediate re-evaluation warranted if: 1
  • Gross hematuria develops
  • Significant increase in degree of microscopic hematuria
  • New urologic symptoms appear (flank pain, dysuria, irritative voiding)
  • Development of hypertension, proteinuria, or evidence of glomerular bleeding