General review of the value of hepatic MRI in the diagnosis and preoperative staging of liver metastases from colon and rectum cancer

Hepatic resection of secondary liver neoplasms is currently the only potent ially curative therapy for patients with primary colorectal carcinoma. Long -term survival is closely related to stage, regardless of the number, size and distribution of liver lesions. Preoperative detection of liver metatast ases is crucial in patient staging and imaging techniques must be as accura te as possible to evaluate whether hepatic resection can be performed. Amon g the various strategies applied to the preoperative detection of liver met astases, CT with intra-arterial portography (CTAP) has been found to be the most sensitive technique. It is an invasive evaluation with a reported sen sitivity ranging from 81 to 94 % but with 6 to 15 % of false-positive resul ts. Recent studies demonstrate that MRI with superparamagnetic iron oxide h as an equivalent sensitivity and specificity to CTAP. This paper reviews th e technique of MRI, evaluates its sensitivity and specificity, and presents the advantages and draw backs of the technique.