IMPROVEMENT OF ULTRASOUND AND MRI METHODS IN THE DETECTION OF LIVER METASTASES AND THEIR DIFFERENTIATION FROM OTHER FOCAL LIVER LESIONS (LITERATURE REVIEW)

Abstract

The liver is one of the most frequent sites of hematogenous metastasis, and metastatic lesions considerably outnumber primary malignant liver tumors. Accurate detection of liver metastases and their differentiation from benign focal lesions determine the stage of the disease and the choice between surgical, systemic and palliative treatment. This review analyzes current data on the capabilities of ultrasound (B-mode, color Doppler imaging, contrast-enhanced ultrasound) and magnetic resonance imaging with diffusion-weighted imaging and hepatobiliary contrast agents in the diagnosis of liver metastases. The ultrasound and MRI patterns of metastases depending on the primary tumor are systematized. Typical diagnostic pitfalls are described: small indeterminate lesions in cancer patients, atypical hemangiomas with "pseudo-washout", abscesses, and changes in the liver parenchyma after chemotherapy. It is concluded that combining ultrasound as the initial and follow-up method with MRI including diffusion-weighted imaging and the hepatobiliary phase provides the highest accuracy of detection and characterization of liver metastases.