الفهرس 
ANATOMY OF THE LIVEROnly 14 pages are availabe for public view
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Abstract
Malignant liver tumors including primary liver cancers and metastases are among the most common tumors in the world. Accurate detection of these tumors 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 and patients with inoperable tumors from being scheduled for surgical procedures.
For hepatic focal lesions detection and characterization, conventional MRI relies on T1-weighted, T2-weighted, and dynamic gadolinium-enhanced T1-weighted imaging.
Diffusion-weighted imaging (DWI) has proved to be useful for the early detection of focal liver lesions. Moreover, it offers the possibility to obtain criteria for lesion characterization- without the need for contrast agent administration-by quantifying diffusion effects via apparent diffusion coefficient (ADC) measurements, with better results compared with those of conventional MR imaging.
So, DWI could potentially be used as an alternate non contrast sequence for detection of liver tumors in patients with poor renal function and in whom gadolinium is contraindicated.
DW imaging could potentially improve care of patients with cancer in cirrhotic liver by improving lesion detection over that achieved with standard breath-hold T2-weighted imaging.
Thus finally to conclude diffusion-weighted MRI sequence with quantitative ADC measurements can be useful in the differentiation of malignant liver lesions. Both qualitative evaluation of high b-value DW-MR images and quantitative evaluation of ADC maps are employed for lesion characterization. DWI proved to be helpful in the characterization of focal liver lesions, but should always be used in conjunction with traditional MRI. It’s an excellent tool in the detection of small HCC in the cirrhotic liver also in hepatic metastases judgment, with higher sensitivity, specificity and positive predictive value compared to conventional contrast enhanced MR; so It seems reasonable to use it in conjugation with conventional imaging.