Magnetic Resonance Imaging of Focal Liver Lesions

Abstract

The main goals of MRI liver techniques are detection & characterization of equivocal hepatic focal lesions with indeterminate results by other diagnostic modalities e.g. US or CT. Malignant liver tumors including primary liver cancers & metastases are among the most common tumors in Egypt & rest of the world. Accurate detection of these lesions is of clinical importance before treatment by resection or radiofrequency ablation as a potential curative treatment. Palliative interventions such as chemo-embolization also require exact lesion localization. Accurate detection is necessary to ensure correct staging, to prevent tumors from being falsely rated as inoperable & patients with inoperable tumors from being scheduled for surgical procedures. Triphasic CT was believed to be the standard in evaluating the hepatic focal lesions & together with alpha fetoprotein, the lesions were decided either non conclusive & needing biopsy or conclusive. According to number & distribution of the lesions (if proved malignant); surgery, radiofrequency ablation, alcohol injection or chemo-embolization was decided. Unfortunately, not all cases with HCC having high alpha fetoprotein & not all cases having typical imaging criteria of HCC & also, not all lesions detected by US are seen in the dynamic CT study. MRI; having many sequences; markedly helps in the detection of small lesions & in reaching the diagnosis easily even without contrast injection.