From the Guidelines
MRI with contrast is the most effective imaging modality for liver hemangioma surveillance, with a sensitivity of 93%, specificity of 99%, accuracy of 98%, PPV of 96%, and NPV of 99% for the diagnosis of hemangioma. The use of contrast-enhanced MRI, particularly with extracellular gadolinium contrast, provides superior characterization of hemangiomas compared to non-contrast MRI 1. The typical enhancement pattern of a hemangioma is best visualized with contrast, allowing for accurate diagnosis and differentiation from other liver lesions such as metastases or hepatocellular carcinoma.
Some key points to consider when using MRI for liver hemangioma surveillance include:
- The combination of diffusion-weighted imaging (DWI) and hepatobiliary phase (HBP) imaging allows for correct classification of lesions as benign or malignant in 91% of cases and exact characterization in 85% of cases 1.
- Gadoxetate-enhanced MRI has an accuracy of 95% to 99% for the diagnosis of hemangioma, making it a highly effective tool for surveillance 1.
- Non-contrast MRI is less sensitive and specific for hemangioma evaluation, potentially missing smaller lesions or changes in existing ones, and its use is based primarily on expert opinion due to a lack of relevant literature 1.
In terms of surveillance protocols, annual or biannual MRI with contrast is recommended for routine surveillance of known stable hemangiomas, depending on the size and location of the lesion. Patients with renal impairment (GFR <30 ml/min) should discuss the risks of gadolinium with their physician, as alternative surveillance methods may be needed 1. Additionally, hemangiomas larger than 5 cm or those located near the liver surface may warrant more frequent monitoring due to a higher risk of complications.
From the Research
Effectiveness of MRI for Liver Hemangioma Surveillance
- MRI with or without contrast can be effective for liver hemangioma surveillance, as it allows for the detection and characterization of hemangiomas with high accuracy and specificity 2, 3, 4.
- The use of contrast-enhanced MRI can provide additional information about the enhancement pattern and rapidity of enhancement of hemangiomas, which can be helpful in differentiating them from other hepatic masses 3, 5.
- However, the addition of gadolinium-enhanced imaging to heavily T2-weighted MR imaging may have a limited role in differentiating hepatic hemangiomas from metastases, and the use of optimized T2-weighted images and T2 relaxation time calculation may be sufficient for diagnosis 5.
- Unenhanced MR examination has been shown to have high sensitivity, specificity, and accuracy in detecting hemangiomas, and may be a suitable method for initial evaluation 4.
Comparison of MRI with Other Imaging Modalities
- MRI has been compared to other imaging modalities such as ultrasound, computed tomography (CT), and contrast-enhanced ultrasound, and has been shown to have advantages in detecting and characterizing hemangiomas 6, 2, 4.
- The use of liver-specific contrast medium such as gadobenate dimeglumine (Gd-BOPTA) in MRI may not significantly improve diagnostic accuracy in discriminating hemangiomas from other liver tumors 4.
Imaging Characteristics of Hemangiomas
- Hemangiomas typically appear as markedly high-intensity areas on T2-weighted MRI images, and may show peripheral nodular arterial enhancement and centripetal filling on contrast-enhanced images 2, 3.
- The T2 relaxation time of hemangiomas is typically prolonged, with a mean value of 133 +/- 25 msec, which can be helpful in differentiating them from other hepatic masses 5.