الفهرس 
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Abstract
Liver cirrhosis represents one of the most common widespread disease in the world due to prevalence of hepatitis viruses and schistosomiasis especially in hyper endemic nations.
In addition, liver cirrhosis is one of the main causes of portal hypertension with resultant compensatory portosystemic shunting and disturbed intrahepatic circulation.
Gastrointestinal hemorrhage is the first cause of death among cirrhotic patients. The risk of hemorrhage is positively correlated with the presence of esophageal varices, the gastric varices and their stage. Esophageal variceal bleeding is a life threatening complication of liver cirrhosis and portal hypertension; of patients with these conditions, 30%– 70% develop esophageal varices. Bleeding from ruptured varices is a very serious complication, with a reported mortality rate of 20%–50%.
Therefore, in cirrhotic patients, detection and prevention of the first esophageal variceal hemorrhage are crucial to minimize complications.
In the past, the radiological investigations were very poor in visualization of varices and for accurate assessment of their site and extension. In addition, some were invasive and not conclusive in its findings. With advance of technology, MDCT offers distinct advantages over traditional spiral CT.
3D MDCT portography becomes superior to conventional angiographic portography for depicting portosystemic collaterals.
The aim of the work is to evaluate and compare the role of MDCT portal angiography as recent less invasive technique for investigation of portosystemic shunts as compared to color Doppler.
MDCT portography provide excellent images in the visualization of portosystemic collaterals and can differentiate between submucosal and perigastric fundal varices which is of clinical interest. In addition, MDCT portography allows identification of the afferent and efferent veins of gastroesophageal varices.Therefore, it can augment the surgeon’s perception of potentially problematic varices by detailing the course of these tortuous vessels.
Among the three rendering, MIP images provide the best visualization of portal vein and portosystemic collaterals. Color Doppler sonography is a useful noninvasive modality for evaluating the hemodynamics of gastric varices, it falls shortly in visualizing the detailed hemodynamics of the inflowing and outflowing vessels of gastric varices in nearly half of patients when compared with CT.
Although endoscopy is the most reliable diagnostic procedure for detecting esophageal varices, CT portography is superior to endoscopy in visualization of submucosal fundal gastric varices and periesophageal and perigastric varices.
Moreover, 3D MDCT portography is useful first for selecting patients as candidates for alternative therapeutic strategies such as balloon occluded retrograde transverse obliteration of gastric varices, second for planning and third for evaluating the embolization therapy.
MDCT portography and Color Doppler have proved to be non invasive and reliable methods for detection of portal vein occlusion and determining its site, extension and whether it partially or totally occluded.
There is close relationship between the velocity of hepatofugal flow in left gastric vein and esophageal variceal size. EVB was more frequent in patients with hepatofugal flow velocity > 15 cm/sec.
Color Doppler can predict the site, size, of varices and its risk of bleeding according to size, blood velocity and direction of flow of the portal, splenic and Left gastric veins. These measurements reflect the severity of portal hypertension, therefore, we can direct patients who are at risk of bleeding to do further assessment by CT portography and upper GIT endoscopy to predict bleeding attacks in cirrhotic patients.