Optimal Plane Selection for Measuring Post-prandial Blood Flow Increase within the Superior Mesenteric Artery:...

Area of Science:

• Medical Imaging
• Cardiovascular Imaging
• Flow Dynamics

Background:

• 2D cine phase contrast (PC)-MRI is a standard technique for superior mesenteric artery (SMA) velocimetry.
• Optimal placement of the measurement plane for SMA velocimetry using 2D cine PC-MRI has not been fully established.
• Meal challenges are used to assess physiological flow responses in the SMA.

Purpose of the Study:

• To determine if SMA flow velocimetry with 2D cine PC-MRI and meal challenge is dependent on measurement plane localization.
• To identify the optimal measurement plane for SMA velocimetry.

Main Methods:

• Seven healthy volunteers underwent 3T 2D cine PC-MRI at proximal, mid, and distal SMA sections before and after a meal challenge.
• 4D Flow (PC VIPR) was performed for detailed flow dynamics analysis using streamline visualization.
• Flow velocities were measured, and abnormal flow patterns were assessed by two radiologists.

Main Results:

• Flow velocity increased post-meal in the proximal and distal SMA sections, but not in the mid-section.
• The distal straight section showed the highest average velocities and lowest variability both pre- and post-meal.
• Streamline analysis revealed more vertical or helical flow patterns in the curved mid-section.

Conclusions:

• SMA velocimetry using 2D cine PC-MRI is significantly influenced by the chosen measurement plane.
• The distal straight section of the SMA is recommended for accurate MR velocimetry.
• Avoidance of the curved mid-section is advised for reliable SMA flow measurements.