Visualization of bile movement using MRI spin-labeling technique: preliminary results

Area of Science:

• Hepatobiliary imaging
• Gastroenterology
• Medical imaging

Background:

• Assessing intrabiliary bile movement is crucial for understanding hepatobiliary function.
• Noninvasive visualization techniques are needed to evaluate bile flow dynamics.
• Current methods may lack the resolution to capture intermittent bile excretion.

Purpose of the Study:

• To develop and validate a novel MRI spin-labeling technique for noninvasive visualization of intrabiliary bile movement.
• To assess the impact of different oral stimuli (water, milk, negative contrast agent) on bile excretion.
• To correlate MRI-derived bile flow with gallbladder volume changes.

Main Methods:

• Six healthy volunteers underwent MRI scans after oral administration of water, full-fat milk, or manganese chloride solution.
• Oblique-coronal T2-weighted images of the common bile duct were acquired using a spin-labeling technique with 22-second intervals.
• Bile flow rate and gallbladder volume changes were measured and analyzed.

Main Results:

• The MRI spin-labeling technique successfully visualized both anterograde and retrograde intermittent bile movements.
• Significantly prolonged bile flow and decreased gallbladder volume were observed after milk administration (p = 0.003).
• Bile flow correlated significantly with gallbladder contractility (p = 0.049).

Conclusions:

• A novel MRI spin-labeling method allows semi-real-time visualization of intrabiliary bile movement.
• Bile excretion occurs in a to-and-fro pattern.
• Oral stimuli like water and negative contrast agents can induce temporary bile excretion, while milk promotes more sustained flow and gallbladder emptying.