Dynamic MRI for bowel motility imaging-how fast and how long?

Area of Science:

• Medical Imaging
• Gastroenterology
• Physiology

Background:

• Dynamic MRI is crucial for studying small intestinal motility in health and disease.
• Quantitative analysis of bowel physiology requires optimized imaging protocols.
• Current data guiding dynamic MRI protocols for small bowel motility are limited.

Purpose of the Study:

• To define the optimal temporal resolution for dynamic MRI in small bowel motility assessment.
• To determine the necessary scan duration for robust quantitative analysis of small bowel motility.
• To establish imaging protocol guidelines for MR enterography.

Main Methods:

• Six healthy volunteers underwent dynamic MR enterography using a high temporal resolution (10 fps) breath-hold protocol.
• Motility was quantified using a registration-derived motility index for local and global regions.
• Data were undersampled and scan duration varied to assess impact on the motility index.

Main Results:

• The mean motility index stabilized at a temporal resolution of 1 fps, with minimal percentage change in global and local regions.
• A scan duration of 15 seconds or more in breath-hold scans led to stabilization of the mean motility index.
• Median absolute percentage changes were low, indicating stability of the motility index at these parameters.

Conclusions:

• A minimum temporal resolution of 1 fps and a scan duration of at least 15 seconds are essential for consistent small bowel motility observations in breath-hold MRI scans.
• Most existing small bowel motility studies align with these recommended parameters.
• This study provides essential data for robust quantitative measurements in dynamic MRI of small bowel motility.