From the Guidelines
Hemangiomas are best diagnosed using MRI with extracellular gadolinium contrast, which has a sensitivity of 93%, specificity of 99%, accuracy of 98%, PPV of 96%, and NPV of 99% 1. When it comes to diagnosing hemangiomas, imaging characteristics play a crucial role. On MRI, hemangiomas typically appear hyperintense (bright) on T2-weighted images due to their high water content, and they show variable signal intensity on T1-weighted images, often appearing hypointense to isointense compared to surrounding tissue. A key diagnostic feature is their enhancement pattern - they demonstrate peripheral nodular enhancement in the arterial phase that progresses centripetally (from outside to inside) in later phases, creating a "fill-in" pattern. Some key points to consider when diagnosing hemangiomas include:
- The use of diffusion-weighted imaging (DWI) and HBP, which allows correct classification of lesions as benign or malignant in 91% of cases and exact characterization in 85% of cases 1.
- The accuracy of gadoxetate-enhanced MRI, which has an accuracy of 95% to 99% for diagnosis of hemangioma 1.
- The importance of considering the lesion itself and the type of contrast used when interpreting MRI results, as performance characteristics of MRI depend on these factors 1. On CT scans, hemangiomas often show peripheral nodular enhancement following contrast administration, similar to the MRI pattern. Without contrast, hepatic hemangiomas may appear hypodense compared to normal liver tissue. In the liver specifically, hemangiomas may demonstrate a characteristic "light bulb" appearance on T2-weighted MRI images due to their extremely high signal intensity. Larger hemangiomas can show central scarring or areas of thrombosis, which appear as non-enhancing regions. While CT with IV contrast may be useful in certain situations, such as when optimal imaging of the airway is required 1, MRI with extracellular gadolinium contrast remains the preferred method for diagnosing hemangiomas due to its high sensitivity and specificity 1.
From the Research
MRI and CT Findings of Haemangioma
- Haemangiomas are uncommon soft tissue tumors, and more than 90% are misdiagnosed initially 2
- Diagnostic ultrasound is an appropriate initial imaging modality for suspected haemangioma, although magnetic resonance imaging (MRI) is the investigation of choice 2
- Computerized tomography (CT) studies may not always be specific for this tumor 2
- Tc 99m RBC blood pool imaging is highly specific diagnostic modality of choice for hepatic haemangioma as its hypervascular nature may create equivocal result on CT or MRI 3
- The sensitivity and specificity of Tc 99m RBC blood pool imaging increases using SPECT especially in lesion less than 2 cm 3
Imaging Characteristics
- Ultrasonography is not always specific in discovering haemangiomas 4
- Liver scintigraphy does not always reveal the typical shape of these tumours 4
- MRI is the investigation of choice for diagnosing haemangiomas 2
- CT studies may show a hypodense lesion with peripheral enhancement 4
Treatment Options
- Surgical excision is the most preferred treatment modality for symptomatic haemangiomas 2
- Embolization of the hepatic artery is a useful procedure in the therapy of symptomatic haemangiomas and haemangiomas with a high risk of bleeding 4
- Minimally invasive embolisation with bleomycin is an alternative and effective treatment for giant symptomatic haemangioma of the liver 5