Liver metastases: The role of magnetic resonance imaging

Abstract

The liver is one of the organs most commonly involved in metastatic disease, especially due to its unique vascularization. It’s well known that liver metastases represent the most common hepatic malignant tumors. From a practical point of view, it’s of utmost importance to evaluate the presence of liver metastases when staging oncologic patients, to select the best treatment possible, and finally to predict the overall prognosis. In the past few years, imaging techniques have gained a central role in identifying liver metastases, thanks to ultrasonography, contrast-enhanced computed tomography (CT), and magnetic resonance imaging (MRI). All these techniques, especially CT and MRI, can be considered the non-invasive reference standard techniques for the assessment of liver involvement by metastases. On the other hand, the liver can be affected by different focal lesions, sometimes benign, and sometimes malignant. On these bases, radiologists should face the differential diagnosis between benign and secondary lesions to correctly allocate patients to the best management. Considering the above-mentioned principles, it’s extremely important to underline and refresh the broad spectrum of liver metastases features that can occur in everyday clinical practice. This review aims to summarize the most common imaging features of liver metastases, with a special focus on typical and atypical appearance, by using MRI.

Complementary comments on metastatic liver lesions with exceptional and rare cases

“…Maino et al [ 1 ] recently published research suggesting the role of magnetic resonance imaging (MRI) in liver metastases. They reviewed the importance of MRI in the diagnosis and evaluation of liver metastases, as well as a description of their primary imaging characteristics.…”

“…Additionally, they described MRI protocols using contrast agents to better diagnose liver metastases. Furthermore, the study emphasises the added value of the most recent imaging tools as well as the usual and atypical appearance of liver metastases, which increases their effect[ 1 ]. This letter aims to contribute to this review by presenting rare and atypical examples of liver metastases.…”

“…According to the authors of this study, hypovascular lesions are the most common typical appearances of liver metastases, but some tumors will present with atypical appearances, such as hypervascular metastases. As mentioned in the literature, hypervascular liver metastases typically arise from hypervascular primary cancers such as neuroendocrine cancers, kidney cancer, melanoma, and thyroid cancer[ 1 , 2 ]. In 73% of patients, hepatic metastases of neuroendocrine tumors displayed a characteristic hypervascular appearance.…”

Magnetic Resonance Imaging Role in Metastatic Liver Disease

“…In a subsequent phase, they are partially excreted through the biliary tree, allowing for enhancement of hepatocytes, hepatocellular lesions, and biliary ducts when non-hepatocellular lesions show reduced enhancement. 10 Gadoxetate disodium is rapidly excreted, leading to a fast excretory phase, allowing for a shorter exam duration. On the contrary, gadobenate dimeglumine has a long excretory phase requiring an acquisition at a later time, often needing two acquisition timings in the same day that may cause exam scheduling diffi-culties.…”