A compact respiratory-triggering device for routine microimaging of laboratory mice

Area of Science:

• Medical imaging
• Physiological monitoring
• Animal research

Background:

• Motion artifacts are a significant challenge in small animal MRI.
• Synchronizing imaging with physiological cycles can improve image quality.
• Existing methods for respiratory monitoring in confined MRI environments are limited.

Purpose of the Study:

• To develop and validate a partial-body plethysmograph for anesthetized mice.
• To utilize respiratory flow data for respiratory-gating in microimaging.
• To assess the impact of respiratory-gating on motion artifacts and lesion contrast.

Main Methods:

• A custom partial-body plethysmograph was designed for use within an 89-mm vertical-bore magnet.
• Respiratory flow signals were recorded from anesthetized mice.
• T2-weighted spin-echo imaging sequences were synchronized with the measured respiratory cycle.
• Image quality, motion artifacts, and liver lesion contrast were evaluated.

Main Results:

• The partial-body plethysmograph successfully measured respiratory flow in mice within the MRI scanner.
• Respiratory-gating significantly reduced motion-induced artifacts in the acquired images.
• An increase in observed liver lesion contrast was achieved through respiratory synchronization.
• The method is compatible with routine microimaging experiments.

Conclusions:

• A partial-body plethysmograph is an effective tool for respiratory monitoring and gating in mouse MRI.
• Respiratory-gating improves image quality by minimizing motion artifacts.
• This technique enhances the detection and characterization of liver lesions in small animal MRI studies.