| The incidence of liver cirrhosis remains high, and its complication-portal hypertension is one of the risk factor that influence living quality of pateint and threat their lives. The primary method to treat portal hypertension is surgical treatment, and due to the complexity of the anatomy of portal collaterals, it is difficult in some degree to determine the operation scheme. Thus, display the anatomy of portal system and collaterals clearly and identifying them effectively is of significance for the treatment of the portal hypertension. Multislice computed tomography (MSCT) with its characters of fast scanning speed, noninvasive testing, various points of view by3D reconstruction and low coast has become one of the major methods to display portal system and its collaterals. Our research works on investigating the best scanning time on healthy people and patients with cirrhosis to improve the imaging quality of portal system and collaterals by using Siemens dual-source CT; on analyzing the anatomy of portal system of healthy people and the collaterals of patients with cirrhosis to assist the clinical treatment by utilizing reconstructure technology, such as MPR, VR and MIP; on studying the relationship between collaterals of patients with portal hypertension and Child-Pugh score.ObjectiveTo investigate the best scanning time for the portal vein and its collaterals on healthy people and patients with cirrhosis by using Siemens dual-source CTMaterials and Methods1. Materials and Grouping From April2011to November,68patients who were accurate diagnosed portal hypertension through laboratory test, ultrasound or gastroscope etc. were selected as portal hypertension group, and we chose28patients as control group who were excluded from liver cirrhosis, metastatic tumor of liver and other diseases which would change the portal system hemodynamics. All the patients never received surgery before.According to the Child-Pugh score, the portal hypertension group were divided into two groups:Child-Pugh A group and Child-Pugh B group whose Child-Pugh score were Child-Pugh B or C. Patients in each group were further divided into four groups (A, B, C, D) randomly.2. Equipments and Scheme of Contrast Injection All the CT scans were performed on Siemens dual-source CT. Contrast agent (non-ionic contrast agent iohexol350mgⅠ/ml) was injected by double tube high pressure syringe at a rate of4.5ml/s. Twenty milliliter contrast agent and15ml physiological saline were injected for test-bolus injection. The volume of contrast medium was intravenously injected according to the body weight of patients (1.4ml/kg) during the formal scan and the upper limit is120ml. Forty milliliter saline was injected immediately after finishing the injection of contrast agent.3. Scanning Plane and ReconstructionAll patients were requested to take800～1000ml water as negative contrast medium before the examination. The plane of main portal vein was2-3cm above its beginning which was chosen as the target sections to be scanned dynamically every2seconds. The scan parameter included:120kv,45mAs, slice thickness10mm, slice interval10mm, and scan number20times. We got all the time-density curves (TDC) of portal vein and aorta.The trigger time of arterial phase is2seconds later to the time of peak enhancement of aorta, and portal venous scan were triggered at3s,5s,7s and9s after the peak time of portal vein respectively to A, B, C, D groups. The scan parameters included:pitch0.6cm,10mm, detector coverage24×12mm, slice thickness for reconstruction1.5mm. The scan coverage was from5cm above the diaphragm to the crista iliaca. All the primary imagings were reconstructed by using Multiplanar Reconstruction (MPR), Maximun Intensity Projection (MIP) and Volum Reconstraction (VR) in Syngo MultiModality Workplace.4. Imaging Evaluation Enhancement of portal vein At the plane of first porta hepatis, measure the CT values of main portal vein, tiny branches of portal vein (d=6±1mm) in liver and liver parenchyma in the same slice, and calculate the difference values of main portal vein and liver parenchyma (P-L1) and difference value of branches and parenchyma(P-L2). Quality of imagingEach group of imaging were reconstructed at workplace and evaluated by radiologists. Observation index included the number of branching grade of portal vein, the image definition and pollution of images.5. Statistic AnalysisStatistic software SPSS13.0was used to evaluate all the data. Peak time of portal vein enhancement, P-L1value, P-L2value and score of images of each group were identified as X±S. P<0.05was considered as statistically significant difference.(1). Comparison of peak time of portal vein enhancement, was evaluated by ONE-WAY ANOVA or Welch if variance is heterogeneity. SNK was performed on multiple comparisons.(2). Comparison of P-L1value, P-L2value and imaging quality were carried out using factorial analysis. If competence factors exist, ONE-WAY ANOVA would be used for comparison in each group with different liver function.Results1. The average enhancement peak time of portal vein are37.11±5.16s、38.50±5.38s、40.89±5.07s respectively to control group, Child-Pugh A group and Child-Pugh B group, F=3.778, P=0.026. The time of Child-Pugh B group was significantly longer than control group.2. Among different time groups, P-L1(F=5.917, P=0.001), P-L2(F=10.690, P=0.000) and image score (F=6.021, P=0.004) had significant statistical difference. P-L1(F=4.229, P=0.015), P-L2(F=4.104, P=0.020) and image score (F=6.021, P=0.004) also had significant differences among different liver function groups. There are competence factors between scane time and liver function, and results are F=8.699, P=0.000, F=7.131, P=0.000and F=6.267, P=0.000for P-L1、P-L2and image score respectively.(1) In Child-Pugh B group, the P-L1value of group C is the highest (F=3.521, P=0.030) and P-L2value (F=4.554, P=0.012); Group B is with the highest P-L1value (F=10.962,P=0.000) in Child-Pugh A group; For control group, the highest P-L1value was detected in group A (F=7.671,P=0.001), as well as the P-L2value. In Child-Pugh A group, the P-L2values of group A and B are not significantly different from each other, but the value of group B is higher.(2) Group A and Group B has the highest score of imaging quality in control group and Child-Pugh A group respectively (F=6.428, P=0.003and F=6.103, P=0.002). In Child-Pugh B group, there was no significant difference (F=2.629, P=0.073) among those groups, but the score of group C is the highest.Conclusions1. The best time to start the portal venous phase scan is to delay3s,5s and7s to the peak contrast of portal vein for the control group, Child-Pugh A group and Child-Pugh B group respectively.2. We should prolong the time to trigger the scan of portal venous phase to get high quality imaging as the liver function become worse (patient with higher Child-Pugh score), which may indicate that the Child-Pugh level of patients with portal hypertension is related to the disturbance of systemic circulation which may be the factor that influenced the imagination of portal system.ObjectivesTo analize the anatomic features of portal vein and its tributaries in healthy people.Materials and Methods1. MaterialsSeventy three patients who would undergo the CT examination were selected randomly from April2011to November. The inclusion criteria are similar to that of control group in part one.There were48male and25female.2. Scanning Plane and Reconstruction The scan scheme and image reconstructed procedure were similar to the part one. The scane time of portal phase is3s later to the peak time of enhancement of portal vein. All the anatomic structures were analyzed combining the axial and reconstructed pictures. The classification of portal vein structures in liver is:type Ⅰ, portal vein devide into left and right branch, then the right branch devide into anterior and posterior right branch. Type Ⅱ, portal vein devide the left, anterior and posterior branch. Type Ⅲ, anterior right branch arised from the left branch. Type Ⅳ, the posterior right branch rise from portal vein firstly, then, portal vein devide into anterior right branch and left branch. The type of tributaries at the right of SMV was classified into five sorts. Type Ⅰ, RGEV and right colic vein drain together. Type Ⅱ, RGEV, right and middle colic veins form one trunk which drain into the SMV. Type Ⅲ, the veins methoned above drain into SMV separately. Type Ⅳ, right and middle colic vein form one trunk. Type Ⅴ, RGEV and middle colic vein drain together. The anatiomy classifications of surgical trunk are single trunk, with a bifurcation, with two bifurcations and ring-shaped.Results1. The most type of portal vein in liver is type Ⅰ(n=63,86.3%). There are5cases (6.8%) of type II and4cases (5.5%) of type Ⅲ. Only one case (1.4%) was type IV.2. The anatomy of draining position of tributaries of portal system 2.1draining position of portal vein’s tributaries Analyzed tributaries of portal vein including left gastric vein (LGV), right gastric vein (RGV), inferior mesenteric vein(IMV). There were38.4%left gastric vein draining into the splenic vein (SV),68.5%into the portal vein,19.2%draining between the portal vein and SV and1.4%LGV was replaced by RGV. Most of RGV drain into portal vein (68.5%). Other positions include SMV (8.2%), left branch of portal vein (4.1%) and RGEV (2.7%). In12cases, the RGV were not displayed clearly. About46.6%IMV drain into SV,32.9%into SMV,19.2%drain between SV and SMV, and1.4%drained into middle colic vein. Paraumbilical vein and cystic vein can not be observed.2.2Tributaries of SMV The surgical trunk without branch at the left side account for41.1%, with one branch account for32.9%, with two branches is19.2%. The ring shaped trunk was not found in our research. While, there were6.8%cases without surgical trunk, whose tributaries confluented at the same level to for the trunk of SMV. We found four types that the tributaries at the right side drained into the SMV and the percentages are45.2%,12.3%,23.3%and19.2%respectively.2.3Rare draining position of tributaries RGEV almost (98.6%) drain into SMV except one rare case that drained into portal vein. SMV drains into middle colic vein (n=1,1.4%) and middle colic vein drains into splenic vein(n=l,1.4%)。Conclusion1. Multi-slice CT portography (MSCTP) can display the anatomy structure of portal vein and its collaterals clearly, which provide accurate anatomic information for transiugular intrahepatic portal-systemic shunts (TIPS), percutaneous transhepatic portal vein embolization (PTPE) and liver transplantation, and reduce the risk and difficulty of operation, shorten the duration of surgery and improve the effect of treatment.2. The anatomic information of portal vein system is useful to minimally invasive surgery.ObjectivesTo analyze the anatomic characteristics of collateral pathways in patients with portal hypertension.Materials and Methods1. MaterialsFrom April2011to November,209patients with portal hypertension were chosen, who were explained to undergo CT test. The including criteria were similar to the portal hypertension group in part one. There are172male and37female, portal hypertension was induced by liver cirrhosis which was due to Virus B hepatitis (n=198), alcohol (n=5), Buddi-Chiari syndrome (n=4), constrictive pericarditis (n=1), and drug-induced hepatitis (n=1)。 The control group was composed of the same patients in part two.2. Equipments and Scheme of Contrast Injection The scan scheme and image reconstructed procedure were similar to the part one. The scan time of portal phase is5s or7s later to the enhancement peak time of portal vein according to the liver function. All the anatomic structures were analyzed combining the axial and reconstructed pictures.3.Statistic Analysis Statistic software SPSS13.0was used to evaluate all the data. Chi-square test was used to compare the rate of the gaonadal vein dilation in patients with portal hypertension and healthy people.Results1. In209cases, the most commen varices included:the esophageal varices account for48.8%, gastric varices75.1%, paraumbilical vein23.4%. There also are some less commen varices:gastric-renal shunt12.9%, spleno-renal shunt7.2%, cystic and paracystic varices10.0%in which the cavernous transformation account for6.7%and all of them were with cancer embolus in portal vein or major branches, varices of gonadal vein9.1%, varices of posterior superior pancreaticoduodenal vein12%, parasplenic vein4.8%and trashepatic portosystemic shunts3.8%, and extensive collaterals formed in the retroperitonium (n=5). Besides, we found11cases of ateriopotal shunts in liver, in which10cases had liver carcinoma and one with a mass in the liver. There were4rare collateral pathways (5.3%), including the mesenteric vein connected with lumbar vein, splenic vein shunted with lumbar vein, right gastroepiploic vein varices (n=1).2. There was no significant difference (P=0.822) of gonandal vein dilation between patients with portal hypertension and healthy people.Conclusions1. MSCTP and the reprocessing reconstruction are kind of effective methods to display the anatomy structure of portal collaterals which will help for making the localized and qualitative diagnose.2. The most common varices are gastroesophageal and paraumbilical varices. Actually, gastrorenal shunt, pararenal varices, subphrenic vein pathway and varices of gonadal vein are not rare. Anatomic characters of portal collaterals should be masterd to provide more effective information for operation and interventional therapy.3. There was no significant difference of gonandal vein dilation between patients with portal hypertension and healthy people.Thus, diagnosis of portal hypertension should be thought carefully when only gonandal vein dilated. |
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