Transverse Scan of the Left and Right Liver Through the Porta Hepatis on Subxiphoid

Transverse liver section • IPorta Hepatis • Subxiphoid approach

Scanning Method

The patient should be fasted for 8–12 hours and examined in the supine position. Place the ultrasound probe transversely in the midline at the subxiphoid region. Direct the probe to obtain a transverse section of the left and right hepatic lobes through the porta hepatis. Adjust the probe angle, depth, and position to clearly demonstrate the liver parenchyma, portal vein and porta hepatis, together with the relevant adjacent structures.

Key scanning point: Begin from the subxiphoid midline with the probe oriented transversely. Identify the porta hepatis and portal vein as the principal anatomical landmarks, then adjust the probe position to obtain a clear transverse view of both the left and right liver.

Ultrasound Image

Figure 1.1 Transverse section of the left and right liver through the porta hepatis on subxiphoid scanning. Insert the corresponding ultrasound image in the space above.

Anatomical / Scanning Diagram

Figure 1.2: Diagram space showing the probe orientation, transverse scanning plane, left and right liver, porta hepatis, portal vein, and labeled anatomical landmarks.

Section Structure

The principal structures demonstrated in this plane are the transverse sections of the left and right hepatic lobes through the porta hepatis. The portal vein and its relationship to the common bile duct and hepatic artery provide important landmarks for confirming the correct transverse orientation.

Structures to identify

• Left hepatic lobe
• Right hepatic lobe
• Porta hepatis
• Main portal vein
• Common bile duct
• Hepatic artery
• Gallbladder, when included in the plane
• Quadrate lobe
• Caudate lobe
• Inferior vena cava (IVC), when included
• Adjacent hepatic parenchyma

Abbreviations Used in the Figure

Short form	Full form	Identification
QL	Quadrate lobe	Hepatic lobe anterior to the porta hepatis.
CHD	Common hepatic duct	Main biliary duct at the porta hepatis.
RPV	Right portal vein	Right portal venous branch.
LPV	Left portal vein	Left portal venous branch.
LL	Left lobe	Left hepatic lobe.
RL	Right lobe	Right hepatic lobe.
CL	Caudate lobe	Caudate lobe adjacent to the IVC.
IVC	Inferior vena cava	Major venous landmark posterior to the liver.
1–5	Numbered structures	Reference numbers corresponding to the labeled diagram.

Measuring Method and Normal

In this transverse subxiphoid plane, measurements may be obtained for the main portal vein and, when indicated, the common bile duct. Measurements should be performed with the vessel or duct clearly visualized and the calipers appropriately positioned.

Measurement	Caliper method	Reference / interpretation
Main portal vein	Measure the internal diameter perpendicular to the long axis of the vessel, preferably with the vessel clearly demonstrated.	Record the measured diameter and interpret it with the clinical context and Doppler findings.
Common bile duct	Measure the duct lumen from inner wall to inner wall at an appropriate location without including the duct wall.	Interpret according to age, clinical setting, and biliary anatomy.

Measurement note: Keep the porta hepatis clearly visualized and place the calipers perpendicular to the structure being measured. Record the measurement location and technique.

The Clinical Application Value

This plane provides a useful transverse view of both hepatic lobes through the porta hepatis. It allows assessment of the liver parenchyma, portal vein, common bile duct, hepatic artery, and adjacent hilar structures.

• Demonstration of the left and right hepatic lobes in transverse section.
• Identification of the porta hepatis as the principal anatomical landmark.
• Visualization of the main portal vein and its branches.
• Assessment of the common bile duct and hepatic artery.
• Assessment of hepatic parenchymal echogenicity and focal abnormalities.
• Recognition of the quadrate and caudate lobes.
• Assessment of hilar vascular and biliary relationships.

Quick Scanning Checklist

1	Fast the patient for 8–12 hours when appropriate.
2	Position the patient supine.
3	Place the probe transversely at the subxiphoid midline.
4	Obtain the transverse view of the left and right liver through the porta hepatis.
5	Identify the main portal vein and porta hepatis.
6	Identify the common bile duct and hepatic artery.
7	Assess the liver parenchyma, hilar structures, and vascular relationships.
8	Obtain portal vein or bile duct measurements when clinically indicated.

Diagnostic Pathology

The transverse subxiphoid view through the porta hepatis can assist in identifying hepatic, biliary, and vascular abnormalities. Evaluate both hepatic lobes, the portal vein, common bile duct, hepatic artery, and surrounding structures.

Key Sonographic Findings

• Hepatomegaly: Increased liver size with altered hepatic morphology.
• Hepatic steatosis: Increased parenchymal echogenicity with reduced visualization of deeper hepatic structures.
• Cirrhotic liver: Coarse echotexture, irregular contour, and altered hepatic architecture.
• Focal liver lesion: Focal area with echogenicity or architecture different from the surrounding hepatic parenchyma.
• Portal vein dilatation: Increased portal vein caliber that may require correlation with Doppler findings and other signs of portal hypertension.
• Portal vein thrombosis: Intraluminal material with partial or complete obstruction of the portal venous lumen.
• Portal hypertension: Portal venous abnormalities with associated collateral vessels, splenomegaly, or other supportive findings.
• Biliary dilatation: Enlargement of the common bile duct or intrahepatic bile ducts.
• Common bile duct obstruction: Dilated duct with possible obstructing stone, lesion, or other abnormality when visualized.
• Choledocholithiasis: Echogenic intraductal focus, often with posterior acoustic shadowing, when a ductal stone is visualized.
• Hilar mass: Focal abnormal tissue involving or adjacent to the porta hepatis, potentially affecting vascular or biliary structures.
• Vascular abnormality: Abnormal caliber, course, or Doppler flow involving the portal vein or hepatic artery.

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