الفهرس 
ANATOMICAL CONSIDERATIONOnly 14 pages are availabe for public view
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Abstract
Liver tumors either benign or malignant including primary liver cancers and metastases are among the most common tumors in the world. Accurate detection of these tumors is of utmost 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 and patients with inoperable tumors from being scheduled for surgical procedures.
Triphasic CT is the standard in evaluating the hepatic focal lesions and together with alpha fetoprotein, the lesions were decided either non conclusive and needing biopsy or conclusive. According to number and distribution of the lesions (if proved malignant) surgery, radiofrequency ablation, alcohol injection or chemoembolization was decided. Unfortunately, not all cases with HCC having high alpha fetoprotein and not all cases having typical imaging criteria of HCC and 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 and in reaching the diagnosis easily even without contrast injection as in cysts and hemangiomas.
Several categories of contrast agents are currently available for magnetic resonance imaging of the liver. They improve lesion detection and characterization by increasing lesion liver contrast. The first agent developed was Gd-DTPA which can accurately detect and characterize many lesions however, many other lesions could not being accurately characterized or even detected by Gd-DTPA. It also have the limitation of being a vascular agent that it is affected by the vascularity of the liver and the tumor.