Unit 3: Biliary Tree Anatomy Part 3

Anterior Gain: Turn down the gain when imaging the gallbladder to eliminate artifacts.
Thorough Survey: Scan thoroughly through the entire gallbladder to avoid missing any pathology. Scan all the way through the organ.
Examine Before Documenting: Always examine the gallbladder before taking images, to avoid mistaking a fold for pathology such as a polyp or stone.
Post-Cholecystectomy Documentation: When a patient is status post cholecystectomy, document it in the report and take pictures of the gallbladder fossa, using the main lobar fissure as a landmark.
Maintain consistency in method and labeling; always scan through, label images consistently, and document the same images in the same order for every patient.
Additional images and views are required if pathology is visualized. If pathology is present, acquire sagittal and transverse views, along with color Doppler and measurements.

Due to variable gallbladder position, a sagittal view might appear circular (transverse) and vice-versa.
If a supposed sagittal view appears circular, it's actually a transverse view. Adjust the transducer to elongate the gallbladder and obtain a true sagittal view.

When measuring the common bile duct, measure only the lumen (inner to inner), excluding the walls.
Measure the duct at its widest point.
Magnify the image if needed for better resolution.
The cystic duct is typically not visualized on ultrasound, making it difficult to identify where the Common Hepatic Duct (CHD) becomes the Common Bile Duct (CBD).
Traditionally:
- CHD is considered superior to the point where the hepatic artery is seen.
- CBD is considered inferior to the hepatic artery.
The transition point (CHD to CBD) is often where you see the sagittal gallbladder and the main lobar fissure.
Distal CBD Location: The distal-most portion of the CBD is found at the posterolateral head of the pancreas.

Distal CBD can measure up to 7mm
Right and left hepatic ducts may need to be measured in addition to the Common Hepatic Duct or Common Bile Duct.
Measurements should be taken in a transverse plane at the porta hepatis region.
At the porta hepatis, the hepatic ducts are anterior or above the branching right and left portal veins.