الفهرس 
Anatomy of the LiverOnly 14 pages are availabe for public view
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Abstract
The liver is an organ in which various benign and malignant (primary or secondary) masses can be detected.
Therapy requires an accurate diagnosis, which in turn relies primarily on appropriate imaging and image-guided biopsy. Although the primary modalities for liver imaging are ultrasound and computed tomography, recent studies have suggested that MRI is the most sensitive method for detecting small liver metastatic lesions, and MRI is now considered the pre-operative standard method for diagnosis.
Magnetic resonance imaging (MRI) is establishing a role as a primary diagnostic technique with evidence showing MR to have advantages over computed tomography (CT) as regards diagnostic sensitivity and specificity for many pathologies of solid organs and so MRI is preferred when further characterization of these masses is needed. MRI plays an increasingly important role in the evaluation of patients with liver disease because of its high contrast resolution, lack of ionizing radiation, and the possibility of performing functional imaging sequences.
MRI has many sequences that help in detection of hepatic focal lesions and in reaching the diagnosis easily even without contrast injection or the need for biopsy.
The clinical applications of diffusion-weighted imaging in the liver include detection and characterization of focal lesions as well as the emerging application in evaluation of post treatment tumor response.
DW MR imaging is an attractive technique for multiple reasons, it can potentially add useful qualitative and quantitative information to conventional imaging sequences, it is quick (performed within a breath hold) and can be easily incorporated to existing protocols, and it is a non-enhanced technique (performed without the use of gadolinium-based contrast media), thus easy to repeat, and useful in patients with severe renal dysfunction at risk for nephrogenic systemic fibrosis.
The ADC maps can also provide quantitative measurements of tissue water diffusivity, which can be used not only for disease assessment, but also for the evaluation of disease response to treatment.
In our study we concluded that diffusion-weighted MRI sequence with quantitative ADC measurements should be used as an additional sequence to supplement conventional MRI protocol studies for proper detection (using low b values) and characterization (using high b values) of solid liver lesions.
The ADC values of benign lesions are significantly higher than those of malignant lesions, with variable degrees of overlap between the pathological entities.
DWI should always be used in conjunction with conventional MRI sequences since there is a degree of overlap between ADC values of benign and malignant lesions. We suggest the following strategy for evaluating DWI features of FHLs. We believe that most of the FHLs can be practically classified as benign or malignant by using this scheme:
Fig. (62): Scheme for classification of FHL.