الفهرس 
Gross anatomy of the liverOnly 14 pages are availabe for public view
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Abstract
Ultrasound is often the first technique used for the detection and characterization of focal liver lesions because of its availability, low cost and safety. Elastography is a form of virtual palpation used to differentiate tissues with different stiffness. Its utility is based on the fact that pathological tissues are generally stiffer than surrounding healthy tissues which often show up as a hard lesion.
Shear -Wave Elastography (SWE) is a new technique based on shear waves that has been implemented in diagnostic ultrasound (US) systems. As in transient elastography, SWE estimates the speed of shear waves to provide a quantitative estimate of tissue stiffness. However, SWE has the advantage of being able to image liver tissue stiffness in real time because the shear waves are generated by US impulses. Moreover, SWE imaging is guided using B-mode images with a higher frame rate. This method can provide more accurate assessment of liver tissue stiffness due to the advantages of SWE and B-mode image guidance. SWE showed a low technical failure rate and acceptable range of intra-observer and inter-observer variability in the stiffness evaluation of liver parenchyma.
Liver is the largest gland in human body. Several distinct types of tumors can develop in the liver because the liver is made up of various cell types. These growths can be benign or malignant .
Our study was conducted on 110 patients ―92 male (83%), 18 female (17%)‖. They were referred to the Diagnostic and Intervention Medical Imaging Department at National Liver Institute. Inclusion criteria were: Patient presented with at least one hepatic focal lesion greater than 1 cm in diameter not more than 5 cm deep from the capsule. Exclusion criteria were Focal lesion previously managed by intervention radiology, patient with perihepatic ascites and uncooperative patients.
The patients‘ age ranged from 30 to 70 years with mean age 50.2 years for the benign lesions and 54.2 years for the malignant. The most encountered clinical presentation in our patients was abdominal distention (40.9%), followed by abdominal pain (36.4%).
Alpha-feto proteins and hepatitis viral markers were significantly higher in malignant lesion than for benign lesions (P-value < 0.001) and also liver function tests with p- value < 0.05
The cirrhotic liver was significantly related to presence of malignant lesions (P-value<0.05). While the size of the liver had no statistically significant relationship to the nature of the lesions (P-value 0.06). Also, the presence of splenomegaly and ascites were significantly related to malignancy (P-value<0.02 & 0.019 respectively).
Out of the studied 110 patients; 82 patients (74.5%) were finally diagnosed with malignant lesions ―70 of them (63.6%) had HCC, 6 patients (5.4%) with cholangiocarcinoma and 6 patients (5.4%) with metastasis‖. 28 patients (25.5%) were finally diagnosed with benign lesions; hemangioma in 24 patients (21.8%) and focal fatty infiltration in 4 patients (3.36%).
All patients ’ lesions were subjected to shear wave elastography scanning. It revealed that there was a significant difference in stiffness (P-value <0.002) between
Summary
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malignant and benign lesions with mean (±SD) of (10.32±6.74) for the benign lesions and (17.23±8.25) for the malignant group.
A cut off point of 13.24 was selected to differentiate between benign and malignant lesions using the SWE mean providing sensitivity 78.04%, specificity 71.42%, positive predictive value 88.8%, negative predictive value 52.6% and accuracy 64.2%.
We found that the 4 focal fatty infiltration were found to have stiffness (mean±SD) values (10.2±5.8kPa), the 24 Hemangioma lesions were found to have stiffness (mean±SD) of (9.5±4.2kPa).The stiffness (mean±SD) of the 70 HCCs was (15.4±7.2kPa), while the stiffness (mean±SD) of the 6 cholangiocarcinoma was (32.5±8.25KPa).The stiffness of the 6 metastatic lesions (mean±SD) was (22.1±0.4kPa).