[Evaluation of diagnostic imagings of liver metastases]

With the advent of various therapeutic modalities for the management of metastatic liver tumor, the task of pretreatment imaging has become more demanding. US and CT are non-invasive, and the most widely used techniques for pretreatment imaging, but they are far from optimal. Recently, the most sensitive pretreatment imaging modality for the depiction of focal liver lesions is CT during arterial portography (CTAP); however, it is an invasive procedure with an established risk of false-positive results. CT and MRI are the sensitivities of these techniques have recently been improved with the development of multidetector CT, contrast agents for MRI that specifically accumulate in the liver, and other advances. Superparamagnetic iron oxide (Feridex) has been developed as a liver-specific particulate MRI contrast agent that is taken up by the Kupffer cells of the liver. Rational selection of appropriate modalities for a given purpose requires familiarity with the characteristics of each modality. The aim of the present study was to evaluate the sensitivities of diagnostic modalities in the pre- and post-treatment periods of metastatic liver tumor. Feridex-enhanced MRI (Ferumoxide MRI) is more sensitive than enhanced CT and MRI in the depiction of metastatic liver tumor. In terms of the ability to visualize residual tumor after MCT, dynamic MRI was superior to enhanced CT and Ferumoxide MRI. In conclusion, combined Ferumoxide MRI and dynamic MRI is a noninvasive method and clinically useful since it can change the therapeutic approach.