الفهرس 
Introduction and aim of the work
ElastographyOnly 14 pages are availabe for public view
 |  | from | 128 |  |  |
| | | from | 128 | | |
Abstract
Cirrhosis poses a difficult challenge for management, while the disease’s prevention, detection, and therapy engender major health costs. In patients with chronic liver disease, the stage of fibrosis is an important factor as it helps decide the therapeutic options and predict the prognosis. Histological examination of percutaneous biopsy specimens is considered the reference standard for assessment of severity of fibrosis and presence of cirrhosis. However, this biopsy only represents 1/50,000 of the entire liver Although a percutaneous liver biopsy is relatively safe, it is still associated with a risk of complications and cannot be used repeatedly in follow-up. Therefore, there is a need for a simple, reliable, non-invasive technique to assess the liver fibrosis stage and cirrhosis Ultrasound is a non-invasive, inexpensive, and repeatable technique for diagnosis of focal and diffuse parenchymal disease of the liver. Various factors, such as liver size, the bluntness of the liver edge, the coarseness of the liver parenchyma, nodularity of the liver surface, gall bladder, presence of collaterals and spleen size have been suggested for US evaluation of chronic liver disease Cirrhosis may change the flow profile of the liver vasculature. Doppler US can provide important information about the haemodynamics of the portal venous system, the hepatic artery, and the hepatic veins. Several indices have been suggested to evaluate hepatic haemodynamic state. However, several limitations of Doppler assessment exist. The remedy for this problem is to add microbubble contrast agents which enhance the Doppler signal from blood. Contrast enhanced ultrasound imaging combined with the CDVP of right portal vein flow can reflect the hemodynamic changes in both compensated and decompensated hepatic cirrhosis. A hepatic vein arrival time (HVAT) cutoff value of 17 s excludes cirrhosis with excellent sensitivity and specificity. Hepatic vein transit time measurement can be used to stage and grade pre-cirrhotic liver disease with clear separation between mild hepatitis and cirrhosis Ultrasound elastography is a new imaging technique that allows a noninvasive estimation and imaging of tissue elasticity distribution within biological tissues using conventional ultrasound equipment with modified software. Liver stiffness measurement (LSM) can detect early stages of cirrhosis in a patient with preserved liver function. LSM values correlate significantly with histological fibrosis scores and US scores. The diagnostic accuracy of LSM is significantly superior to US in the prediction of F > 1 and cirrhosis In conclusion, various US techniques, including grey-scale imaging, Doppler US, contrast-enhanced US (CEUS), and elastography can significantly help in the diagnosis and grading of liver cirrhosis with high degree of sensitivity and specificity.