Short-Axis Scanning of the Gallbladder Neck by the Right Subcostal

Short-Axis Scanning of the Gallbladder Neck by Right Subcostal

Short-axis gallbladder section • Gallbladder Neck • Right subcostal 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 right subcostal region. Direct the probe to obtain a short-axis section of the gallbladder neck. Adjust the probe angle and position to clearly demonstrate the gallbladder neck, adjacent liver parenchyma, and relevant anatomical structures.

Key scanning point: Begin from the right subcostal region with the probe oriented transversely. Identify the gallbladder neck as the principal anatomical landmark and adjust the probe position to obtain a clear short-axis view of the gallbladder neck and its relationship with the adjacent liver and biliary structures.

Ultrasound Image

Figure 1.1 Short-axis section of the gallbladder neck obtained by right subcostal scanning. Insert the corresponding ultrasound image in the space above.

Anatomical / Scanning Diagram

Figure 1.2: Diagram space showing the probe orientation, scanning plane, gallbladder neck, right subcostal approach, and labeled adjacent anatomical landmarks.

Short-Axis Scanning of the Gallbladder Neck by the Right Subcostal

The principal structures demonstrated in this plane are the right lobe of the liver (RL), gallbladder neck (GB Neck), gallbladder (GB), common hepatic duct (CHD), right hepatic duct (RHD), and adjacent upper abdominal structures.

Structures to Identify

• Right lobe of the liver (RL)
• Gallbladder (GB)
• Gallbladder neck (GB Neck)
• Cystic duct region
• Right hepatic duct (RHD)
• Common hepatic duct (CHD)
• Adjacent hepatic parenchyma
• Adjacent upper abdominal structures

Abbreviations Used in the Figure

Abbreviation	Full Form	Identification
RL	Right Lobe of Liver	Right hepatic lobe demonstrated on the right side of the image.
LL	Left Lobe of Liver	Left hepatic lobe visualized in the upper portion of the scan.
Gb	Gallbladder	Gallbladder visualized as an anechoic fluid-filled structure.
CBD	Common Bile Duct	Common bile duct visualized within the porta hepatis.
PHA	Proper Hepatic Artery	Arterial structure associated with the portal triad.
PV	Portal Vein	Portal venous structure within the porta hepatis.
IVC	Inferior Vena Cava	Major venous structure posterior to the liver.
Ao	Aorta	Abdominal aorta visualized posterior to the liver.

Scanning Technique

For short-axis evaluation of the gallbladder neck, place the patient in the supine position and use a right subcostal approach. Position the transducer beneath the right costal margin and obtain the gallbladder in cross-section. Adjust the probe position and angle to demonstrate the gallbladder neck clearly and follow its continuity toward the cystic duct.

Step	Scanning Method
1	Position the patient supine.
2	Place the transducer in the right subcostal region.
3	Identify the gallbladder beneath the right hepatic lobe.
4	Rotate or angle the transducer to obtain a short-axis view.
5	Identify the gallbladder neck in cross-section.
6	Follow the neck toward the cystic duct when visualized.
7	Assess the surrounding hepatic parenchyma and biliary structures.

Measuring Method and Normal

When clinically indicated, assess the gallbladder neck in short axis for its shape, wall appearance, luminal contents, and relationship to the adjacent biliary structures.

Assessment	Method	Interpretation
Gallbladder neck	Evaluate in short axis with the neck centered within the image.	Assess morphology, lumen, wall, and any focal abnormality.
Gallbladder wall	Measure perpendicular to the wall when quantitative assessment is clinically indicated.	Interpret together with gallbladder distension and clinical findings.
Neck lumen	Assess for echogenic material, shadowing calculi, sludge, or other intraluminal abnormality.	Document associated posterior acoustic shadowing or mobility when demonstrated.

Measurement note: Keep the gallbladder neck clearly visualized in short axis and avoid including adjacent hepatic tissue or surrounding structures in wall measurements.

The Clinical Application Value

Short-axis scanning of the gallbladder neck through the right subcostal approach provides a focused view of the gallbladder neck and its relationship to the surrounding hepatic and biliary anatomy.

• Demonstration of the gallbladder neck in short axis.
• Assessment of gallbladder wall morphology.
• Evaluation of gallbladder lumen and intraluminal contents.
• Identification of gallstones or sludge when visualized.
• Assessment of the cystic duct region when adequately visualized.
• Assessment of the adjacent right hepatic parenchyma.
• Evaluation of the right hepatic and common hepatic ducts when included in the plane.

Quick Scanning Checklist

1	Fast the patient for 8–12 hours when appropriate.
2	Position the patient supine.
3	Place the probe in the right subcostal region.
4	Identify the gallbladder beneath the right hepatic lobe.
5	Rotate or angle the probe to obtain the short-axis view.
6	Identify the gallbladder neck.
7	Assess the gallbladder wall and lumen.
8	Look for calculi, sludge, or focal intraluminal abnormalities.
9	Follow the neck toward the cystic duct when visualized.
10	Assess adjacent hepatic and biliary structures for abnormalities.

Diagnostic Pathology

Short-axis evaluation of the gallbladder neck may assist in identifying gallbladder and biliary abnormalities. The gallbladder neck, wall, lumen, cystic duct region, and adjacent hepatic structures should be assessed when adequately visualized.

Key Sonographic Findings

• Gallstone: Echogenic intraluminal focus, typically with posterior acoustic shadowing when adequately demonstrated.
• Impacted neck calculus: Echogenic calculus located at or near the gallbladder neck, potentially associated with obstruction.
• Gallbladder sludge: Low-level dependent echoes within the gallbladder lumen, without the typical clean posterior acoustic shadow of a calculus.
• Gallbladder wall abnormality: Focal or diffuse wall thickening or altered wall appearance.
• Gallbladder distension: Increased gallbladder size or altered configuration.
• Focal gallbladder lesion: Focal intraluminal or wall-based abnormality differing from the expected gallbladder appearance.
• Biliary duct abnormality: Dilatation or altered appearance of the visualized RHD or CHD.
• Pericholecystic abnormality: Abnormal fluid or altered echogenicity adjacent to the gallbladder when visualized.

Diagnostic note: Abnormal findings should be interpreted together with the complete abdominal ultrasound examination, clinical history, laboratory findings, and additional imaging when indicated. A single sonographic finding should not be used in isolation to establish a diagnosis.