Simultaneous ECG-gated PET imaging of multiple mice

Area of Science:

• Cardiovascular Research
• Medical Imaging Technology
• Animal Models in Research

Background:

• Positron Emission Tomography (PET) research on cardiac dynamics can be limited by low throughput.
• Simultaneous imaging of multiple subjects is desirable to improve efficiency in preclinical studies.
• Accurate gating is crucial for analyzing dynamic cardiac processes using PET.

Purpose of the Study:

• To develop and validate a method for simultaneous Electrocardiogram (ECG)-gated Positron Emission Tomography (PET) imaging in multiple mice.
• To enhance the throughput of cardiac dynamics research using PET.
• To enable detailed analysis of cardiac function and tracer kinetics in individual animals during a single imaging session.

Main Methods:

• Fabrication of a 3D-printed imaging bed for simultaneous PET imaging of two side-by-side mice.
• Continuous analysis of individual ECG signals to generate independent R-wave trigger markers.
• Acquisition of PET data in list mode, incorporating trigger markers for subsequent data sorting.
• Spatial separation of data based on animal location within the field of view to create independent gated image sequences.

Main Results:

• Successful generation of two independent ECG-gated PET image sequences from a single data acquisition.
• Demonstration of accurate cardiac cycle representation, including dynamic changes in ventricular cavity volumes, for each mouse.
• Validation of the method by observing expected variations in cardiac dynamics in processed animals and minimal variation in unprocessed controls.

Conclusions:

• The described method enables the creation of individual ECG-gated image sequences for multiple animals from a single PET data collection.
• This approach significantly increases the efficiency and throughput of cardiac PET imaging studies.
• The method is extensible to more animals and other physiological gating techniques, such as respiratory gating.