Imaging evaluation of the liver in oncology patients: A comparison of techniques

Abstract

The liver is commonly affected by metastatic disease. Therefore, it is essential to detect and characterize liver metastases, assuming that patient management and prognosis rely on it. The imaging techniques that allow non-invasive assessment of liver metastases include ultrasonography, computed tomography (CT), magnetic resonance imaging (MRI), positron emission tomography (PET)/CT, and PET/MRI. In this paper, we review the imaging findings of liver metastases, focusing on each imaging modality’s advantages and potential limitations. We also assess the importance of different imaging modalities for the management, follow-up, and therapy response of liver metastases. To date, both CT and MRI are the most appropriate imaging methods for initial lesion detection, follow-up, and assessment of treatment response. Multiparametric MRI is frequently used as a problem-solving technique for liver lesions and has evolved substantially over the past decade, including hardware and software developments and specific intravenous contrast agents. Several studies have shown that MRI performs better in small-sized metastases and moderate to severe liver steatosis cases. Although state-of-the-art MRI shows a greater sensitivity for detecting and characterizing liver metastases, CT remains the chosen method. We also present the controversial subject of the "economic implication" to use CT over MRI.

Keywords: Liver metastases; Magnetic resonance imaging; Computed tomography; Oncology; Ultrasound; Follow-up

Core Tip: Several imaging methods are clinically available to evaluate and characterize liver metastases. Both computed tomography and magnetic resonance imaging (MRI) are currently the techniques that show the highest diagnostic performance and are also the most suitable for assessing therapy response and follow-up. Several studies have shown that MRI has a higher sensitivity for detecting and characterizing liver metastases; therefore, it may be the ideal imaging method for treatment planning before and after neoadjuvant chemotherapy. The traditional paradigm for ordering imaging studies emphasizes diagnostic accuracy, which is why we believe that MRI should be favored when available, the first-line imaging for detecting liver metastases, and pre- and post-treatment follow-up.