CT Hemangioma Protocol
For hepatic hemangiomas, perform multiphase CT with IV contrast using a dynamic bolus protocol that includes arterial phase imaging (20-30 seconds), portal venous phase (60-70 seconds), and delayed phase imaging (3-5 minutes post-contrast) to capture the characteristic peripheral nodular enhancement with progressive centripetal fill-in. 1, 2
Protocol Components
Pre-Contrast Phase
- Obtain baseline non-contrast images to establish lesion attenuation values 2
- Hemangiomas typically demonstrate diminished attenuation (lower density than surrounding liver) on pre-contrast scans 2
Contrast Administration
- Bolus injection technique: Administer 150 mL of 60% iodinated contrast material at 6 mL/second 1, 2
- For body CT imaging, OPTIRAY 300,320, or 350 can be used with doses ranging from 25-75 mL bolus or 50-150 mL infusion 3
Dynamic Scanning Phases
Arterial Phase (Early Phase)
- Scan at 20-30 seconds post-injection 1, 4
- Look for intense peripheral nodular enhancement with density similar to aorta or hepatic arteries 1
- This peripheral enhancement should be well-defined and nodular in appearance 1
Portal Venous Phase
- Scan at 60-70 seconds post-injection 2
- Observe for progressive centripetal enlargement of enhanced nodular regions 1, 4
Delayed Phase
- Obtain scans at 3-5 minutes, and up to 30-60 minutes if needed 1, 2
- Complete isodense fill-in should occur, though larger hemangiomas may show incomplete filling due to focal scarring or hemorrhage 5, 2
- The lesion should retain contrast and become isodense with surrounding liver parenchyma 2
Diagnostic Criteria
Three essential CT criteria for specific hemangioma diagnosis: 2
- Diminished attenuation on pre-contrast scan
- Peripheral nodular contrast enhancement during arterial/dynamic phase
- Complete isodense fill-in on delayed scans (up to 60 minutes)
Alternative high-specificity criteria: 1
- Intense mural nodular enhancement in arterial phase with density matching aorta/hepatic arteries
- Well-defined nodular enhancement areas
- Centripetally oriented enlargement of nodular regions
Technical Considerations
Scan Parameters
- Use thin-section CT (2.0 mm thickness, 2.0 mm interval) for optimal visualization 6
- Maximum enhancement typically ranges from 90-110 HU 6
Timing Strategy
- For arterial phase: 15 scans during first 30 seconds after bolus injection 1
- For delayed phase: 2 scans/minute up to 30 minutes if needed 1
- Centripetal filling typically takes 1-3 minutes but can require 3-5 minutes for complete visualization 5
Common Pitfalls and Caveats
Atypical presentations: 5
- Small hemangiomas (15-40 mm) and large hemangiomas (>4 cm) may show atypical features
- High-flow hemangiomas demonstrate rapid enhancement that can mimic hepatocellular carcinoma or focal nodular hyperplasia 5
- Incomplete late filling is common in larger hemangiomas due to scarring or hemorrhage 5
Diagnostic limitations: 2
- The classic three-criteria pattern is seen in only 55% of hemangiomas, making CT relatively limited compared to MRI for definitive diagnosis 2
- When CT findings are indeterminate, MRI should be performed for definitive characterization 5
Patient preparation:
- Ensure adequate hydration before and after contrast administration 3
- Avoid extravasation, especially in patients with severe arterial or venous disease 3
Alternative Imaging Considerations
When CT is suboptimal: 5
- MRI has higher diagnostic accuracy (85-93%) for hemangiomas compared to CT 5
- Contrast-enhanced ultrasound (CEUS) shows 88-90% sensitivity and 99% specificity for hemangioma diagnosis with typical peripheral nodular enhancement pattern 5
- CEUS can definitively characterize 80-90% of hemangiomas and is particularly useful for lesions deemed indeterminate on grayscale ultrasound 5