الفهرس 
Introduction.Only 14 pages are availabe for public view
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Abstract
The number of detected congenital anomalies & variants of the portal venous
system has increased in recent years due to the use of MDCT and 3D imaging
techniques. The diagnosis is made primarily with Doppler ultrasonography but CT
angiography is essential for further evaluation and assessment of accompanying
anomalies. Variants are frequent and account for 20 to 35% of the population.
These variants must be diagnosed before complex hepatectomy, split or living
donor transplantation, and before complex interventional procedures such as portal
vein embolization.
Also MDCT and post processing techniques can provide adequate information
about the acquired abnormalities of the portal venous system as in porto-systemic and
porto-portal collateral vessels, occlusion of the portal vein, intra-hepatic arterioportal
shunts, portal vein gas, thrombosis, or stents in the portal venous system
This study was conducted on 150 patients 107 males and 43 females. Their
ages ranged from 1-85 years. One hundred and twenty two patients had history of
liver cirrhosis out of whom 53 had HCC on top. Out of whom 53 HCC diseased
patients, 20 showed PV thrombosis,12 patients had +ve malignant PV thrombosis
associated with malignant A-P fistula. The remaining 21 patients had malignant
PV thrombosis without malignant A-P fistula.
Triphasic multidetector CT study & post processing techniques (MIP,
MPR, MinIP and VRT) were performed for all cases &statistical analysis for the
collected data was done.
Our results showed that the portal vein branching pattern, type A (normal
branching pattern) represented 72.7% followed by type B variant (12.7%), type D
variant (9.3%) & lastly type C variant represented 5.3%. Portal vein type B was
more common among female patients.
MDCT is a non invasive imaging modality for assessment of the acquired
abnormalities as portal hypertension and collateral formation that account for 18.7
% of the studied patients. Portal vein thrombosis was found in 56 patients out of
whom 23 patients had benign thrombus, 21 patients had malignant thrombus and
12 patients had malignant thrombus with vascular invasion and subsequent
malignant arterio-portal fistula.
MDCT study clarified the significant relationship between the incidence of
portal vein thrombosis either benign or malignant and the presence of liver
cirrhosis. It also showed a significant relationship between the presence of HCC
and the incidence of malignant portal vein thrombosis and malignant arterioportal
fistula.
We finally concluded that:
Multislice CT serves as an important non invasive imaging modality in
diagnosis of portal vein variant, congenital anomalies as well as the
acquired abnormalities of the portal vein.
MDCT portography and post processing techniques can replace most of
the invasive methods including conventional angiography and
portography. Post processing mini MIP images can also provide MRCP
like images for proper evaluation of the billiary tree as in cases of portal
bilopathy.
Summary and conclusion
Knowing the branching variants, congenital anomalies and acquired
abnormalities is very important prior to surgical resection or living
donor transplantation and before complex interventional procedures
such as portal vein embolization.
In addition to diagnosis of portal vein abnormalities also multislice CT
plays an important role in evaluation of associated abnormalities as liver
cirrhosis, hepatocellular carcinoma& bowel lesions or ischemia.