Umbilical Portion Research Articles

Surgical Ligation of Extrahepatic Shunt under Guidance of Doppler Ultrasound, Portography, and Portal Pressure Monitoring

A 54-year-old man with chronic hepatitis C was admitted to our hospital because of a disturbance of consciousness and hyperammonemia. Abdominal angiography revealed a portosystemic shunt between the superior mesenteric vein and inferior vena cava. Endoscopic examination showed no varix. As interventional treatment was unsuccessful, surgical ligation of the shunt was performed. After surgery, portography revealed a huge shunt. Before ligation, the portal pressure, portal flow speed, and volume at the umbilical portion were 24 H2O. 5.6 cm/s and 203 ml/min, respectively. Finally the shunt was ligated. The portal flow speed and volume increased for 14 days following surgery and then stabilized. No varices were observed postoperatively. Doppler ultrasound, portography, and portal pressure monitoring can be used to reveal haemodynamic changes in the portal system and justify surgical ligation of portosystemic shunt.

Resection of metastatic liver cancer in a patient with a left-sided gallbladder and intrahepatic portal vein and bile duct anomalies: A case report

INTRODUCTIONThe presence of left-sided gallbladder is closely associated with multiple combined anomalies of the portal vein, hepatic vein, hepatic artery, and bile duct. This requires special attention for preoperative evaluation for the purpose of preventing postoperative complications. PRESENTATION OF CASEA 70-year-old woman with metastatic liver cancer and intrahepatic portal vein, biliary system and hepatic artery anomalies with left-sided gallbladder is reported. On computed tomography (CT), a solitary low density mass occupied from the right anterior to the posterior segment of the liver. The gallbladder bed was on the left of the hepatic fissure. On drip-infusion-cholangiography (DIC) CT three-dimensional (3D) reconstruction, the left medial bile duct arose from the right umbilical portion after arising from the left lateral bile duct. Following a right hepatectomy and lymph node dissection of the hepatoduodenal ligament, hepaticojejunostomy was conducted separately to the left medial and left lateral bile duct. DISCUSSIONThe left-sided gallbladder accompanies with several anomalies of hepatic vascular and bile duct anomalies in a frequent manner. A safe hepatectomy needs accurate operative plans to ascertain the range of hepatectomy, because it often has the diversity of a combined anomaly. CONCLUSIONPreoperative DIC-CT 3D reconstruction was extremely useful because it provided an important information that could not be obtained with 2D-DIC-CT. 3D imaging has the ability to demonstrate complex anatomical relationships, this devise is a effective new tool for making appropriate preoperative strategy.

Gallbladder metastasis from hepatocellular carcinoma: Report of a case and review of literature

INTRODUCTIONThe incidence of metastasis of hepatocellular carcinoma (HCC) to the gallbladder is low. Here, we report a case of HCC with metastasis to the gallbladder and discuss the pattern of spread and the treatment. PRESENTATION OF CASEA 74-year-old man was diagnosed with advanced hepatocellular carcinoma. Computed tomography and magnetic resonance imaging demonstrated a tumor in the right lobe of the liver with a thrombus in the bifurcation of the portal vein. Because intraoperative ultrasonography showed portal vein tumor thrombosis from the main tumor reaching the umbilical portion, we performed only a cholecystectomy for the elimination of postoperative cholecystitis. Pathological examination showed gallbladder vein tumor thrombosis from poorly differentiated hepatocellular carcinoma. DISCUSSIONA preoperative diagnosis of metastatic HCC to the gallbladder is difficult because there are no specific findings in the imaging tests. Cancer cells in the liver were thought to migrate to the gallbladder via the connection between the portal system and the cholecystic veins, and grow in the lumen of the veins in our case. The survival rate, in all reported cases including the present case, was increased in patients who underwent radical resection, compared to patients who underwent palliative surgery. CONCLUSIONThe resection of metastatic HCC to the gallbladder might appear to prolong survival.

True left-sided gallbladder with a portal anomaly: report of a case

A 65-year-old female who presented with back pain was diagnosed to have the presence of biliary sludge in the gallbladder. Computed tomography showed that the round ligament connected to the left portal umbilical portion was in the normal anatomical position. However, the gallbladder was located to the left of the middle hepatic vein and the round ligament, attached to the left lateral segment of the liver. The right posterior portal vein diverged alone from the main portal vein, and there was a long stem from the right anterior and left portal veins. Laparoscopic cholecystectomy confirmed the abnormal location of the gallbladder. Most reported cases of left-sided gallbladder are caused by a right-sided round ligament, which is called a "false" left-sided gallbladder. A case of left-sided gallbladder with a normal left-sided round ligament, which is designated as a case of "true" left-sided gallbladder, is extremely rare.

Laparoscopy-Assisted Right Hepatectomy and Caudate Lobectomy with Portal Reconstruction for Hilar Cholangiocarcinoma

Introduction: Laparoscopic resection of hilar cholangiocarcinoma remains uncommon because of its technical difficulties.1,2 However, the main site of the operation for hilar cholangiocarcinoma is the right subcostal area, and most procedures, including major hepatectomy and even vascular reconstruction, can be performed through a 10-cm right subcostal incision if mobilization of the liver is carried out laparoscopically. This video demonstrates our novel minimally invasive technique of laparoscopy-assisted right hepatectomy and caudate lobectomy with portal reconstruction for advanced hilar cholangiocarcinoma. Materials and Methods: The patient in the video was an 82-year-old woman who was diagnosed to have hilar cholangiocarcinoma (Bismuth type IV). The patient was placed in left hemilateral position to switch easily between the supine and left lateral position. First, a 10-cm minilaparotomy incision was made at the right subcostal margin. During lymphadenectomy of the hepatoduodinal ligament, the feasibility of the operation was finally confirmed, including the possibility of vascular reconstruction. In the video case, there was portal vein invasion at the level of the bifurcation. Then the right hepatic artery and the common bile duct were divided. Gelport (Applied Medical, Rancho Santa Margarita, CA) was put on the subcostal incision and laparoscopic mobilization of the liver was performed with four trocars added. In addition to the mobilization of the lateral segment and the right lobe, the caudate lobe was completely mobilized from the inferior vena cava. A parenchymal transection was performed using a modified hanging maneuver through the minilaparotomy incision, using the same method as for open liver resection. The left hepatic duct was divided adjacent to the umbilical portion. As we reach the posterior surface of liver, the right hepatic vein was dissected and divided using a linear stapler. After clamping the portal trunk and left portal branch as far from the portal bifurcation as possible, the portal vein was resected and the specimen was retrieved through the minilaparotomy. Portal reconstruction was performed in an end-to-end fashion. Roux-en-Y hepaticojejunostomy was finally performed. Results and Conclusions: A total of three cases underwent laparoscopy-assisted right hepatectomy and caudate lobectomy (with portal reconstruction in one case). The mean operative time was 672 minutes and the mean blood loss was 1047 mL. There were no intraoperative complications. Histological examination of resected specimens revealed curative status with clear margins in all cases. We conclude that this operation is feasible and safe. It should be currently performed with appropriate expertise in both hepatobiliary and minimally invasive surgery. Larger trials are needed to determine whether this approach offers any advantage over the standard open approach. The authors have nothing to disclose. Runtime of video: 7 mins 51 secs

Segmentectomy of the liver

Segmentectomy is anatomical resection of segments based on the classification of Couinaud. This procedure is performed mainly for hepatocellular carcinoma. Invasion of portal vein and intrahepatic metastases often occur with hepatocellular carcinoma. Thus, it is desirable to perform anatomical resection of the cancer-bearing areas for curative purpose. However, segmentectomy is selected when extensive resection must be avoided to preserve liver function. There are major differences between segmentectomy of the left hemiliver (Sg 2-4) and right hemiliver (Sg 5-8). In the former, the branches (third-order branches) arising from the umbilical portion of the portal vein can be ligated prior to liver resection. In the latter, manipulation is difficult. Therefore, ultrasonically guided segmental staining is performed by puncturing the portal branch and injecting a dye. This report described techniques for segmentectomy.

Central bisectionectomy (bisegmentectomy) of the liver (with video)

Surgical techniques and indications for central bisectionectomy (bisegmentectomy) of the liver, i.e., resection of Couinaud's segments 4, 5 and 8, are described. Parenchymal dissection between the left medial and lateral sections is performed by dividing Glisson's branches arising from the right side of the umbilical portion towards the confluence between the middle and left hepatic veins. Parenchymal dissection between the right anterior and posterior sections is performed along the demarcation line created by obliterating the Glisson's pedicle of the right anterior section (Couinaud's segments 5 and 8), and then along the left side of the right hepatic vein. The root of the middle hepatic vein is divided at the bottom of the right and left plane of the parenchymal division. The indications for central bisectionectomy include benign and malignant tumors occupying both the left medial and right anterior sections, i.e., Couinaud's segments 4, 5 and 8, while sparing the left lateral and right posterior sections, i.e., Couinaud's segments 2, 3, 6 and 7. This technique is advocated especially for liver tumors arising in chronic liver diseases such as hepatocellular carcinoma complicating viral hepatitis and metastatic liver tumor with concomitant steatosis of the non-cancerous liver parenchyma, for which right or left trisectionectomy could result in less than optimal remnant liver volume and function.

Use of preoperative, 3-dimensional magnetic resonance cholangiopancreatography in pediatric choledochal cysts

Standard choledochal cyst (CC) operations involve dilated extrahepatic bile duct excision followed by biloenterostomy. However, biliary variants and associated intrahepatic bile duct (IHBD) stenoses or dilatations triggering postoperative sequelae require additional procedures. The usefulness of preoperative 3-dimensional magnetic resonance cholangiopancreatography (3D MRCP) and virtual cholangioscopy (VES) for observing biliary morphology and pancreaticobiliary maljunction (PBM) was evaluated. In 16 pediatric CC patients (age range, 4 months to 9 years; median, 3 years), visualization of PBM and aberrant bile duct anatomy and IHBD morphology at the hepatic hilum (HH), umbilical portion (UP), and posterior branch (POST) were compared between 3D-MRCP and intraoperative cholangiography (IOC). VES and intraoperative cholangioscopy (IOS) findings were compared. HH, UP, and POST visualization rates were 100%, 94%, and 94%, respectively, by 3D-MRCP, and 100%, 69%, and 69%, respectively, by IOC. IHBD stenosis detection rates at each region were 38%, 13%, and 13%, respectively, by 3D-MRCP, and 25%, 0%, and 9%, respectively, by IOC. IHBD dilatation detection rates at each part were 75%, 47%, and 60%, respectively, by 3D-MRCP, and 88%, 82%, and 91%, respectively, by IOC. PBM was confirmed in 56% and 93% of cases on 3D-MRCP and IOC, respectively. Both 3D-MRCP and IOC showed biliary variants in 5 cases (31%). VES showed membranous strictures at HH, UP, and POST in 6, 2, and 2 cases, respectively, whereas IOS did so at HH in 4 cases and POST in 2. Preoperative 3D-MRCP and VES accurately depict biliary morphology, allowing concrete operative planning in pediatric CC patients, complementing IOC and IOS.

Interventional percutaneous trans-splenic approach in the management of portal venous occlusion after living donor liver transplantation

Interventional percutaneous trans-splenic approach in the management of portal venous occlusion after living donor liver transplantation

Safety of combined resection of the middle hepatic artery in right hemihepatectomy for hilar biliary malignancy

In patients with hilar biliary malignancies, preservation of the middle hepatic artery (MHA, segment IV artery) where it runs close to the tumor in the hepatic hilum may lead to resection with positive margins. This retrospective study assessed the safety of combined resection of the MHA with right hemihepatectomy, caudate lobectomy, and bile duct resection for hilar biliary malignancies. Of 61 patients with hilar biliary malignancies who underwent right hemihepatectomy, we classified the branching patterns of the MHA according to the origins and courses in the hilum. The MHA was resected without reconstruction in 16 patients in whom the artery ran close to the tumor. We compared the perioperative outcomes in these patients with those of patients who did not undergo resection of the artery. Anatomically, the MHA ran on the right side of the umbilical portion of the portal vein in 40 (66%) patients. Perioperative data for the patients who underwent combined resection were similar to those in whom the MAH was preserved. There were no postoperative complications that could be directly related to the arterial resection. Combined resection of the MHA during right hemihepatectomy for hilar biliary malignancies has a safe perioperative course.

The superior group of vessels in the falciform ligament: anatomical and radiological correlation

The purpose of this study was to clarify the anatomical detail of the superior group of vessels in the falciform ligament in terms of the relationship with the internal thoracic vessels, inferior phrenic vessels, and the intrahepatic portal vein. (1) Anatomical study: we dissected eight adult human cadavers (seven normal and one cirrhotic liver) to determine the relationship between the superior group of vessels in the falciform ligament, the internal thoracic vessels, and the inferior phrenic vessels. (2) Clinical study: we determined the origin and destination of the superior group of veins demonstrated in 8 of 4,006 patients with chronic liver disease who underwent the contrast enhanced CT scans. (1) Anatomical study: the superior group of vessels anastomosed the right (n = 4), left (n = 2), and both (n = 2) internal thoracic vessels. They also anastomosed the left (n = 4), right (n = 1), and both (n = 2) inferior phrenic vessels. (2) Clinical study: the origin of the veins was identified as the left medial branch (n = 4), left lateral branch (n = 1), both the lateral and medial branches (n = 1), and the vein from the umbilical portion (n = 2) of the left portal vein. The drainage vein was identified as the left (n = 3), right (n = 2), and the both (n = 1) internal thoracic veins. We demonstrated the anastomoses between the superior group of vessels of the falciform ligament, the internal thoracic vessels, the inferior phrenic vessels, and the intrahepatic portal vein. These pre-existing anastomoses would develop as porto-systemic shunt in patients with portal hypertension.

Selection of Appropriate Liver Resection in Left Hepatolithiasis Based on Anatomic and Clinical Study

Because of the possibility of injury to the left medial section of the bile duct (B4) and the presumed higher recurrence rate of hepatolithiasis, some surgeons have recently preferred left hepatectomy for left hepatolithiasis. We investigated the appropriate treatment for left hepatolithiasis by evaluating the anatomy and variations of the left hepatic duct system in a normal population and analyzed the clinical outcome of liver resection. We reviewed the magnetic resonance imaging results of 115 normal subjects who underwent a workup for living related liver donation. An imaginary surgical resection line was established based on the lateral margin of the umbilical portion of the liver in T2-weighted axial images. The junction of B4 with the left hepatic duct was evaluated to determine the possibility of injury during liver resection. We also analyzed the clinical outcomes of 181 patients who underwent left lateral sectionectomy or left hepatectomy. The anatomic evaluation showed that B4 joined lateral to the umbilical portion of the liver in 7.0% (8/115) of cases. In patients with left hepatolithiasis, left hepatectomy was performed in 79 patients and left lateral sectionectomy in 102. The operating time for the left lateral sectionectomy was significantly shorter than that for left hepatectomy (p=0.001). There were no significant differences in complications or recurrence of stones. Preoperative cholangiography should be performed to evaluate the anatomy of the left hepatic duct to avoid injuring B4. For most cases of left hepatolithiasis without a left hilar stricture, left lateral sectionectomy is the safest, most effective treatment.

Role of three-dimensional imaging in operative planning for hilar cholangiocarcinoma

Complex, highly variable, anatomic relationships in the portal hilum complicate the surgical management at hilar cholangiocarcinoma. Preoperative three-dimensional (3D) imaging to stage the tumor and define anatomy may help in planning for curative resection. Between 2003 and 2006, 20 consecutive patients with hilar cholangiocarcinoma underwent preoperative multidetector row computed tomography (MDCT) cholangiography; 3D images of the portal vein, hepatic artery, and bile ducts were created and viewed simultaneously. Longitudinal tumor extension was evaluated by direct cholangiography and 3D cholangiography, and contiguous spread by 2D computed tomography (CT). Of 20 patients, 15 underwent surgical resection. Liver resection was planned based on 3D imaging that allowed visualization of the relationship between the tumor and the umbilical portion of the left portal vein, or the bifurcation of the anterior and posterior branch of the right portal vein. Preoperative and operative findings were compared. All patients tolerated 3D CT without serious complication. The accuracy rates of longitudinal tumor extension, using the Bismuth-Corlette classification system, were 85% (11/13) and 87% (13/15) with direct cholangiography and 3D cholangiography, respectively. The sensitivity, specificity, and accuracy rates were 100%, 80%, and 87% for portal invasion and 75%, 91%, and 87% for hepatic arterial invasion. The number of bile duct orifices in the cut end of the hilar plate was estimated correctly in 13 of 15 patients. There were no operative deaths. Potentially curative resection was achieved in 14 of 15 patients. 3D images provide accurate information about the relationship between hilar cholangiocarcinoma and adjacent vessels. This technique is a powerful new tool for improving the proportion of potentially curative resection.

Hepaticojejunostomy and intrahepatic cystojejunostomy for type IV-A choledochal cyst

Background The incidence of choledochal cyst with intrahepatic involvement (Todani's type IV-A cyst) is considerably high. Dilatation of the intrahepatic bile duct is frequently observed around the hepatic hilum, occasionally in the umbilical portion, and rarely in the more upstream intrahepatic bile duct, associated with or without downstream stricture. We recently encountered 2 children with type IV-A cyst associated with upstream intrahepatic ductal dilatation; one with a cystic dilatation of the medial branch arising from the left hepatic duct and another with a cyst of the medial branch arising from the anterior hepatic duct. Methods After excision of the extrahepatic bile duct cyst at the hilum and making a large fenestration of the intrahepatic duct cyst, hepaticojejunostomy and intrahepatic cystojejunostomy were performed using a Roux-en-Y jejunal loop in both children. Results Postoperatively, both intrahepatic cysts were remarkably reduced in size, and recurrent bouts of abdominal pain did not occur for up to 4 or 5 years. Conclusion Hepaticojejunostomy at the hepatic hilum, combined with intrahepatic cystojejunostomy, appears to be a recommendable procedure for an upstream intrahepatic ductal cyst of type IV-A, preventing postoperative cholangitis owing to bile stone formation.

Left-sided gallbladder: Its clinical significance and imaging presentations

To assess the importance of preoperative diagnosis and presentation of left-sided gallbladder using ultrasound (US), CT and angiography. Retrospective review of 1482 patients who underwent enhanced CT scanning was performed. Left-sided gallbladder was diagnosed if a right-sided ligamentum teres was present. The image presentations on US, CT and angiography were also reviewed. Left-sided gallbladder was diagnosed in nine patients. The associated abnormalities on CT imaging included portal vein anomalies, absence of umbilical portion of the portal vein in the left lobe of the liver, club-shaped portal vein in the right lobe of the liver, and difficulty in identifying segment IV. Angiography in six of nine patients demonstrated abnormal portal venous system (trifurcation type in four of six patients). The main hepatic arteries followed the portal veins in all six patients. The segment IV artery was identified in four of six patients using angiography, although segment IV was difficult to define on CT imaging. Hepatectomy was performed in three patients with concomitant liver tumor and the diagnosis of left-sided gallbladder was confirmed intraoperatively. Left-sided gallbladder is an important clinical entity in hepatectomy due to its associated portal venous and biliary anomalies. It should be considered in US, CT and angiography images that demonstrate no definite segment IV, absence of umbilical portion of the portal vein in the left lobe, and club-shaped right anterior portal vein.

Fusion of the midplane with the left intersectional plane: a liver anatomical variation revisited with multidetector-row CT

This article updates the description of an anatomical variation of the liver, in which the gallbladder is adjacent to the ligamentum teres, that was described until now as "right-sided ligamentum teres and right umbilical portion of the portal vein". A study of eight patients showing this anatomical variation has led to a new archetypal anatomical description of the hepatic and portal veins, using multidetector-row computed tomography (MDCT) with three-dimensional (3D) volume-rendering (VR) reconstructions. While 2D axial imaging gave the same information, MDCT imaging with VR reconstructions provided a clear 3D visualization of this anatomical variation. Typical features can be described as follows: (1) juxtaposition of the ligamentum teres and the gallbladder; (2) typical portal vein branching with a right posterior branch, a left posterior branch and a main medial branch that terminates in the ligamentum teres; (3) two main hepatic veins and a hypotrophied medial hepatic vein. We think, based on the direct comparison of anatomical findings and knowledge of chronological embryological development, that this abnormality results from the defective development of the central part of the liver and not from the persistence of the right rather than the left umbilical vein. Because of the presence of only one medial plane, containing both the gallbladder and the ligamentum teres, we propose renaming it "fusion of hepatic planes".

Types and Frequencies of Biliary Tract Variations Associated with a Major Portal Venous Anomaly: Analysis with Multi–Detector Row CT Cholangiography

To retrospectively determine whether major portal venous variation was more frequently associated with biliary variants, with consideration of the types and frequencies of biliary tract variations in the right and left liver lobes. Before undergoing computed tomographic (CT) cholangiography, patients gave informed consent. The retrospective research protocol was approved, and informed consent was waived by the ethics committee. Forty-four patients aged 29-80 years who underwent multi-detector row CT cholangiography had a major portal vein variation in which the main portal vein diverged into the common trunk of the left portal vein and right anterior sectorial portal vein. One hundred fifty-eight consecutive patients aged 26-89 years who did not have this variation served as the control group. Three radiologists retrospectively evaluated the confluence pattern of the bile duct, the relationship between this pattern and the portal vein, and the major branching pattern of the portal vein. Pearson chi2 and Fisher exact tests were performed to identify significant differences between the two patient groups. The classic hilar confluence pattern, where the right posterior sectorial duct connects supraportally with the right anterior sectorial duct, was less frequent in the patients with the portal vein variation than in the control subjects (32% vs 73%, P < .05). The following biliary tract variations were identified more frequently in the variation group than in the control group (P < .05): right posterior sectorial duct joining left hepatic duct with a supraportal course (34% vs 12%), right posterior sectorial duct joining right anterior sectorial duct with an infraportal course (13% vs 4%), right posterior sectorial duct following an infraportal course (23% vs 8%), and left lateral segmental ducts caudal to the umbilical portion of the portal vein (14% vs 3%). The right hepatic duct, which receives all biliary ducts from the right lobe, was significantly less frequently developed in the variation group (46% vs 79%, P < .05). In addition, retroportal bile ducts were seen in four patients with the portal vein variation (P < .05). Bile duct configurations in patients with portal vein variation were significantly different from those in control subjects.

Truncoumbilical bypass of the portal vein in radical resection of biliary tract tumour involving the hepatic duct confluence

Before combined resection of the right hepatic lobe and the hepatoduodenal ligament, an autogenous external iliac vein was interposed between the root of the portal vein trunk and the umbilical portion of the vein in four patients with biliary tract tumour. The left hepatic arterial pathway was preserved, except in one case in whom resection of this artery was followed by reconstruction. This procedure allowed successful and safe extended right hepatic lobe resection and combined en bloc resection of the hepatoduodenal ligament while preserving hepatic blood perfusion.

Anomaly of the Portal Vein With Total Ramification of the Intrahepatic Portal Branches From the Right Umbilical Portion

To describe CT findings of portal vein anomaly with total ramification of the intrahepatic portal branches from the right umbilical vein. Retrospective analysis was performed in 6 patients with portal vein anomaly with total ramification of the intrahepatic portal branches from the right umbilican vein. We analyzed the position of the umbilical portion of the portal vein and ligamentum teres, and determined the intrahepatic branching pattern of the portal vein. The umbilical portion and ligamentum teres were deviated to the right and seen above the gallbladder fossa in all 6 patients. All major braches of the portal vein ramified from the right umbilical vein in all 6 patients. The possibility of this portal vein anomaly should be kept in mind when hepatic resection or partial liver transplantation is required.

Gadolinium-Enhanced Phase-Contrast Magnetic Resonance Portography

The purpose of this study was to investigate the effect and usefulness of gadolinium-chelated contrast medium in phase-contrast magnetic resonance (MR) portography. Twenty-six patients (21 men, 5 women; aged 34 to 79 years, mean 62 years) underwent respiratory-triggered 3-dimensional phase-contrast portography before and after administration of gadolinium in a 1.5T MR unit. Coronal maximum intensity projection (MIP) images of the portal vein were reconstructed and compared to conventional arterial portograms regarding visualization. Signal-to-noise ratio (SNR) and portal vein-to-liver contrast-to-noise ratios (CNR) of main, right, right anterior, right posterior, left portal veins, and umbilical portion were measured on both non-enhanced and gadolinium-enhanced images and compared. Portal veins and branches were more clearly visualized on the gadolinium-enhanced than on the non-enhanced images. Compared to arterial portography, gadolinium-enhanced portography showed similar performances in visualization, except in the right posterior branch and left portal vein. No severe image degradation from respiration was experienced. SNR was significantly higher on the gadolinium-enhanced than on non-enhanced images except in the right anterior branch. CNR was significantly higher on the gadolinium-enhanced than on the non-enhanced images at all measured locations. Administration of gadolinium improves the SNR and CNR of phase-contrast portography and visualization of the portal vein. The phase-contrast technique with gadolinium enhancement can be used to evaluate the portal vein as a supplemental technique.