Longitudinal Scanning of the Liver Through the Abdominal Aorta

Longitudinal liver section • Abdominal aorta • Subxiphoid approach

Scanning Method

The patient should be fasted for 8–12 hours and examined in the supine position. Place the ultrasound probe vertically in the midline at the subxiphoid region. Adjust the probe to obtain the longitudinal section of the left hepatic lobe together with the abdominal aorta and the relevant adjacent structures.

Key scanning point: Start from the subxiphoid midline with the probe vertically oriented. The abdominal aorta is used as an important anatomical landmark for establishing the longitudinal plane.

Ultrasound Image

Figure 1. Longitudinal section of the liver and abdominal aorta. Insert the corresponding ultrasound image in the space above.

Anatomical / Scanning Diagram

Figure 8.2: Diagram space for the probe orientation, scanning plane, liver, abdominal aorta, and labeled anatomical landmarks.

1.1.2 Section Structure

The principal structures demonstrated in this plane are the longitudinal section of the left hepatic lobe and the abdominal aorta, with an oblique section of the esophagus. The adjacent vascular structures help confirm the correct anatomical orientation.

Structures to identify

• Left hepatic lobe
• Abdominal aorta
• Esophagus (oblique section)
• Celiac artery
• Splenic artery
• Splenic vein
• Superior mesenteric artery
• Pancreatic body
• Left atrium

Abbreviations Used in the Figure

Abbreviation	Full form	Role / identification
LL	Left lobe	Longitudinally visualized left hepatic lobe.
CA	Celiac artery	Arterial branch arising from the abdominal aorta.
LA	Left atrium	Cardiac structure included as an adjacent landmark in the depicted plane.
PB	Pancreatic body	Part of the pancreas seen adjacent to the vascular structures.
SpV	Splenic vein	Venous structure coursing toward the portal venous system.
SpA	Splenic artery	Arterial branch related to the celiac trunk.
SMA	Superior mesenteric artery	Arterial branch arising inferior to the celiac artery.
Ao	Aorta / abdominal aorta	Major arterial landmark used to establish the scanning plane.
E	Esophagus	Obliquely visualized esophageal section.

1.1.3 Measuring Method and Normal

Measure the anteroposterior (AP) diameter of the left hepatic lobe from the top of the anterior hepatic capsule to the posterior capsule in the appropriate longitudinal section.

Measurement	Caliper method	Reference value from the supplied source
Left hepatic lobe AP diameter	Measure from the top of the anterior capsule to the posterior capsule.	< 7 cm in the normal liver.

Measurement note: Keep the measurement in the standardized longitudinal plane and document the plane and measurement direction with the value.

1.1.4 The Clinical Application Value

This plane is described as a standard section for measuring the anteroposterior diameter of the left liver lobe. It also permits assessment of the liver's size, shape, and parenchymal echogenicity.

• Standard plane for left hepatic lobe AP measurement.
• Assessment of left-lobe size.
• Assessment of hepatic shape and contour in the demonstrated plane.
• Assessment of hepatic parenchymal echogenicity.
• Recognition of the abdominal aorta as a major orientation landmark.
• Recognition of the adjacent celiac, splenic and superior mesenteric vessels.

Quick Scanning Checklist

1	Fast the patient for 8–12 hours.
2	Position the patient supine.
3	Place the probe vertically at the midline of the subxiphoid region.
4	Obtain the longitudinal left-lobe view with the abdominal aorta.
5	Identify the labeled vascular and adjacent structures.
6	Measure the AP diameter of the left hepatic lobe from anterior to posterior capsule.
7	Compare the measurement with the supplied reference of <7 cm.
8	Assess liver size, shape and parenchymal echogenicity.

Ultrasound Scanning technique for liver

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Liver Ultrasound Scanning Technique

PATIENT PREPARATION • EQUIPMENT • IMAGE OPTIMIZATION • SYSTEMATIC SCANNING • DOPPLER • DOCUMENTATION

ULTRASOUND SCANNING TECHNIQUE

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SYSTEMATIC SCANNING PRINCIPLE: Use a consistent sequence so that the liver is assessed in multiple planes and approaches. Adapt patient position, respiration and probe approach according to visualization, body habitus and clinical requirements.

Longitudinal Scanning of the Liver Through the Abdominal Aorta

Longitudinal Scanning of the Liver Through the Inferior Vena Cava on Subxiphoid

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

Transverse Scanning of the Left Hepatic Lobe Through the Left Portal Vein Branches by Subxiphoid

Longitudinal Scanning of the Left Hepatic Lobe Through the Caudate Lobe and Medial Lobe

Oblique Scanning of the Left External Hepatic Lobe

Oblique Scanning of the Left Hepatic Lobe and Caudate Lobe

Longitudinal Scanning of the Hepatic Left Lobe and the Ligamentum Teres Hepatis by Subxiphoid

Oblique Scanning of the Ligamentum Teres and the Left Liver by Subxiphoid

Oblique Scanning of the Liver Through the Gallbladder and Inferior Vena Cava by the Right Subcostal Margin

Oblique Scanning of the Liver Through the Hepatic Veins and the Second Porta Hepatis on Subxiphoid

Transverse Scanning of the Upper Part of the Porta Hepatis

Transverse-Oblique View of the Left Liver Through the Longitudinal Section of the Left Hepatic Vein on the Subxiphoid

Oblique Scanning of the Right Liver Through the Porta Hepatis

Longitudinal Scanning of the Liver Through the Middle Hepatic Vein on Subxiphoid

Longitudinal Scanning of the Right Liver Through the Porta Hepatis

Oblique Scanning of the Right Anterior Liver and the Left Medial Lobe of the Liver by Right Intercostal Space

Oblique Scanning of the Dome Area in the Right Liver from the Right Intercostal Space Approach

Oblique Scanning of the Right Liver Through the Right Portal Vein by the Right Subcostal Space Approach

Longitudinal Scanning of the Right Liver and Right Kidney from the Right Subcostal

Oblique Scanning of the Right Liver Through the Right Hepatic Veins on Subxiphoid

Longitudinal Scanning 1 of the Right Liver Through the Porta Hepatis on the Right Subcostal

Longitudinal Scanning 2 of the Right Liver Through the Porta Hepatis

Transverse Scanning of the Porta Hepatis from the Right Subcostal

Transverse Scanning of the Right Liver and the Right Kidney from the Right Subcostal

Oblique Scanning of the Right Liver Through the Dome of the Right Diaphragm from the Right Subcostal

Longitudinal Scanning of the Common Hepatic Artery and Splenic Artery from the Upper Abdomen

Common Hepatic Artery Blood Flow Spectrum

Longitudinal Scanning of the Proper Hepatic Artery from the Upper Abdomen

Proper Hepatic Artery Blood Flow Spectrum

Portal Vein Blood Flow Spectrum from the Right Subcostal Margin

PRE-EXAMINATION PRINCIPLE

Follow the local examination protocol and clinical indication. Explain the examination to the patient and obtain relevant clinical history before scanning.

Confirm patient identity and examination indication.

Review relevant clinical history, symptoms and previous imaging when available.

Explain the liver ultrasound examination to the patient.

Use appropriate fasting instructions according to local protocol and clinical circumstances.

Position the patient comfortably, usually supine initially.

Be prepared to use left lateral decubitus or other positional changes when required.

Ask the patient to cooperate with respiration and breath-holding when necessary.

Expose the examination area appropriately while maintaining patient privacy.

Apply adequate ultrasound gel to obtain consistent acoustic coupling.

Use additional positioning or respiratory maneuvers when the liver or dome is poorly visualized.

Select an appropriate abdominal curvilinear transducer.

Use a suitable frequency range for the patient's body habitus and required penetration.

Inspect the transducer surface and cable before use.

Confirm adequate acoustic coupling and apply sufficient gel.

Preset the ultrasound system for abdominal/liver examination when available.

Confirm the correct patient information on the ultrasound system.

Prepare Color Doppler and Spectral Doppler modes when vascular assessment is required.

Ensure measurements and image storage functions are available.

Select an appropriate monitor display and examination environment.

Optimize the system before acquiring the final diagnostic images.

1. Probe Orientation and Contact

Maintain correct probe orientation and consistent acoustic contact. Use sufficient gel and adjust probe pressure according to the target structure and patient's body habitus.

2. Depth Optimization

Adjust depth so the liver and relevant surrounding anatomy are appropriately displayed without excessive unused field of view.

3. Overall Gain Optimization

Adjust overall gain to produce a balanced grayscale image. Avoid excessive gain or insufficient gain that suppresses useful information.

4. Time Gain Compensation — TGC

Adjust TGC controls to compensate for depth-dependent attenuation and maintain relatively consistent image brightness through the liver.

5. Frequency Optimization

Select the highest practical frequency that provides adequate penetration and image quality. Lower frequencies may be required when deeper penetration is necessary.

6. Dynamic Range and Compression

Adjust dynamic range/compression to obtain useful grayscale separation and appropriate visualization of hepatic parenchyma.

7. Reject / Suppression Optimization

Use reject or suppression controls carefully. Excessive suppression may remove clinically useful low-level information.

8. Zoom and Field-of-View Optimization

Use an appropriate field of view. Magnify the region of interest when detailed assessment or measurement is required.

9. Color Doppler Optimization

Optimize the color box, scale, gain, wall filter, persistence and color priority according to the vessel and clinical question.

10. Spectral Doppler Optimization

Optimize the sample gate, Doppler scale, baseline, wall filter, gain and sweep speed. Apply appropriate angle correction when velocity measurement is required.

11. Measurement Optimization

Place measurement calipers precisely on the intended anatomical landmarks using an appropriate imaging plane and magnification.

12. Image Documentation

Save representative images documenting the liver, relevant vascular structures, measurements and Doppler findings according to protocol.

Vessel / Assessment	Technique Focus
Common Hepatic Artery	Obtain a suitable longitudinal view and optimize color and spectral Doppler for assessment of arterial flow.
Proper Hepatic Artery	Identify the vessel and acquire an appropriate spectral Doppler tracing after image optimization.
Portal Vein	Assess the portal vein from an appropriate subcostal approach and document the blood-flow spectrum according to protocol.
Hepatic Veins	Use appropriate subxiphoid or other suitable approaches to visualize hepatic venous anatomy and flow when required.
Color Doppler	Adjust scale, gain, wall filter, box size and other controls to demonstrate vascular flow without excessive background noise.

DOPPLER NOTE: Use Doppler settings and velocity/flow measurements required by the clinical indication and local laboratory protocol. When velocity measurement is required, use appropriate angle correction and maintain a suitable Doppler angle according to the examination protocol.

Select the appropriate anatomical plane before placing calipers.

Magnify the target structure when necessary.

Place calipers precisely on the intended anatomical margins.

Avoid oblique measurements when a standardized plane is required.

Record measurements with the correct units.

Repeat measurements when the first acquisition is technically suboptimal.

Document the image plane or anatomical reference when appropriate.

Use consistent technique for follow-up examinations whenever possible.

Document representative images of the left hepatic lobe.

Document representative images of the right hepatic lobe.

Document the porta hepatis when assessed.

Document relevant hepatic veins and portal venous structures.

Document the gallbladder relationship when relevant to the scanning sequence.

Document the liver–right kidney relationship when obtained.

Document the hepatic dome when adequately visualized.

Save appropriate Color Doppler images when vascular assessment is performed.

Save appropriate Spectral Doppler tracings.

Save measurement images with visible calipers and labels.

Use appropriate anatomical labels and patient identifiers according to local protocol.

Ensure stored images are technically adequate before completing the examination.

LIVER SCAN COMPLETION CHECKLIST

Confirm that the required liver regions, scanning planes, vascular structures, measurements, Doppler assessments and representative images have been completed according to the clinical indication and local examination protocol.

Left hepatic lobe assessed.

Right hepatic lobe assessed.

Caudate/medial region assessed where required.

Porta hepatis assessed.

Hepatic veins assessed where required.

Portal vein assessed where required.

Hepatic arterial Doppler completed where indicated.

Right hepatic dome assessed where technically possible.

Right liver–kidney relationship documented where required.

Required measurements completed.

Required Doppler spectra documented.

Final images reviewed for technical quality.

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Liver Ultrasound Scanning Technique • Systematic • Practical • Diagnostic