Transverse Scanning of the Upper Part of the Porta Hepatis

Transverse liver section • Upper Part • Porta Hepatis Aproche

Scanning Method

The patient should be fasted for 8–12 hours and examined in the supine position. Place the ultrasound probe in the right upper abdomen or epigastric region with the transducer oriented transversely. Use the liver as an acoustic window and angle the probe slightly cephalad or caudad as required to obtain a transverse view of the upper part of the porta hepatis. The scanning plane should demonstrate the main portal vein, hepatic artery, bile duct, and adjacent hepatic parenchyma as appropriate. The gallbladder neck may also be visualized depending on the level of scanning. Gentle respiratory maneuvers may be used to improve visualization of the porta hepatis. Optimize depth, gain, focal position, and probe angulation to clearly demonstrate the portal triad and its anatomical relationships.

Key scanning point: Begin in the right upper abdomen or epigastric region with the probe placed transversely. Use the liver as an acoustic window and direct the transducer slightly cephalad to identify the upper part of the porta hepatis. The main portal vein serves as the principal landmark, with the hepatic artery and bile duct identified in relation to it. Adjust the probe position, pressure, and respiratory phase to demonstrate the portal vein, hepatic artery, bile duct, gallbladder neck, and surrounding hepatic parenchyma within the same transverse scanning plane. Maintain adequate depth and gain to clearly define the portal triad and its anatomical relationships at the upper porta hepatis.

Ultrasound Image

Figure 1.1 Transverse sonographic section of the upper part of the porta hepatis obtained through the right upper abdominal or epigastric approach, demonstrating the main portal vein (MPV), hepatic artery (HA), and bile duct (BD) within the hepatic scanning plane, along with the surrounding hepatic parenchyma and relevant vascular landmarks.

Anatomical / Scanning Diagram

Figure 1.2: Diagram showing the transverse probe orientation across the right upper abdomen or epigastric region and the corresponding transverse scanning plane through the upper part of the porta hepatis, demonstrating the main portal vein (MPV), hepatic artery (HA), and bile duct (BD), with the surrounding hepatic parenchyma and relevant hepatic and vascular anatomical landmarks.

Section Structure

The principal structures demonstrated in this transverse plane of the upper porta hepatis include the left lobe of the liver (LL), right hepatic duct (RHD), left hepatic duct (LHD), right portal vein (RPV), and left portal vein (LPV). These structures provide important anatomical landmarks for orientation of the hepatic biliary and portal venous anatomy.

Structures to Identify

• Left lobe of the liver (LL)
• Right hepatic duct (RHD)
• Left hepatic duct (LHD)
• Right portal vein (RPV)
• Left portal vein (LPV)
• Hepatic parenchyma

Abbreviations Used in the Figure

Short form	Full form	Identification
LL	Left Lobe of Liver	Hepatic parenchyma of the left hepatic lobe surrounding the porta hepatis and providing the principal acoustic window.
RHD	Right Hepatic Duct	Biliary duct draining the right hepatic lobe and forming an important landmark within the upper porta hepatis.
LHD	Left Hepatic Duct	Biliary duct draining the left hepatic lobe and serving as an important biliary landmark within the porta hepatis.
RPV	Right Portal Vein	Portal venous branch supplying the right hepatic lobe and serving as an important vascular landmark.
LPV	Left Portal Vein	Portal venous branch supplying the left hepatic lobe and providing an important landmark for hepatic orientation.

Measuring Method and Normal

In this transverse plane of the upper porta hepatis, measurements may be obtained when clinically indicated. The right hepatic duct (RHD), left hepatic duct (LHD), and portal venous structures should be measured only when they are clearly visualized in an appropriate standardized imaging plane. Calipers should be placed perpendicular to the walls of the target structure, avoiding oblique measurements and adjacent hepatic tissue.

Measurement	Caliper Method	Reference / Interpretation
RHD	Measure the internal ductal caliber perpendicular to the long axis of the right hepatic duct when clearly visualized.	Interpret according to the measurement site, degree of visualization, and clinical context.
LHD	Measure the internal ductal caliber perpendicular to the long axis of the left hepatic duct when clearly visualized.	Interpret according to the measurement site, degree of visualization, and clinical context.
Portal vein	When clinically indicated, measure the portal venous caliber in an appropriate transverse or standardized imaging plane with clear visualization of the vessel walls.	Interpret according to the measurement site, Doppler findings, respiratory variation, and clinical context.

Measurement note: Obtain measurements only when the target structure is clearly defined. Avoid oblique measurements and inclusion of adjacent hepatic tissue, vessels, or bile ducts.

The Clinical Application Value

This transverse plane of the upper porta hepatis provides an anatomical overview of the hepatic biliary and portal venous structures, demonstrating important landmarks including the LL, RHD, LHD, RPV, and LPV. Recognition of these structures assists in assessment of the anatomical relationship between the hepatic ducts and portal venous branches.

• Demonstration of the left lobe of the liver (LL).
• Identification of the right hepatic duct (RHD).
• Identification of the left hepatic duct (LHD).
• Identification of the right portal vein (RPV).
• Identification of the left portal vein (LPV).
• Assessment of the surrounding hepatic parenchyma.
• Assessment of the anatomical relationship between the hepatic ducts and portal venous structures.

Quick Scanning Checklist

1	Fast the patient for 8–12 hours when appropriate.
2	Position the patient in the supine position.
3	Place the probe across the upper abdomen in a transverse orientation.
4	Use the left hepatic lobe as an acoustic window when appropriate.
5	Adjust the probe position and angulation to obtain the upper porta hepatis in transverse section.
6	Identify the LL.
7	Identify the RHD and LHD.
8	Identify the RPV and LPV.
9	Optimize depth, gain, focus, and probe pressure for clear visualization.
10	Assess the anatomical relationship of the biliary ducts and portal venous branches.

Diagnostic Pathology

This transverse upper porta hepatis view can assist in the assessment of hepatic, biliary, and portal venous abnormalities. The LL, RHD, LHD, RPV, and LPV should be evaluated together with the complete abdominal sonographic examination.

Key Sonographic Findings

• Hepatic ductal abnormality: Altered caliber, dilatation, irregularity, or other abnormality involving the RHD or LHD should be documented.
• Intrahepatic biliary dilatation: Dilated intrahepatic biliary channels may be identified and should be assessed in relation to the visible hepatic ducts.
• Portal venous abnormality: Altered caliber, intraluminal thrombus, abnormal flow, or other abnormality involving the RPV or LPV.
• Hepatic parenchymal abnormality: Altered echogenicity, coarse echotexture, focal lesions, or architectural distortion involving the LL should be documented when present.
• Focal hepatic lesion: Focal abnormality differing in echogenicity or architecture from the surrounding hepatic parenchyma.
• Portal hypertension: Abnormal portal venous caliber, altered flow, or collateral venous vessels may be identified in the appropriate clinical setting.
• Porta hepatis abnormality: Any abnormal mass, altered anatomy, ductal change, or vascular abnormality within the porta hepatis should be documented.

Diagnostic note: Sonographic findings should be interpreted together with the complete abdominal ultrasound examination, Doppler assessment, clinical history, and relevant laboratory findings. A single sonographic finding should not be used in isolation to establish a diagnosis.