Related Experiment Video
Updated: Jul 3, 2026
3D Cine Magnetic Resonance Imaging of Respiratory Motion in Mechanically Ventilated Mice and Rats
Published on: September 19, 2025
A robust optical respiratory trigger for small rodents in clinical whole-body MR systems
Karl-Heinz Herrmann1, Enrico Wagner, Andreas Deistung
1AG Medizinische Physik, Institut für interventionelle und diagnostische Radiologie, Universitätsklinikum Jena, Jena, Germany. Karl-Heinz.Herrmann@med.uni-jena.de
Abstract:
An increasing number of animal experiments are currently conducted on clinical MR systems. Motion artefacts due to breathing can become quite apparent, in particular with abdominal examinations. These artefacts can be reduced by using a triggered acquisition. However, the built-in detectors in human whole-body scanners are usually not sensitive enough to detect the tiny movements of small rodents. Therefore, a sensitive optical motion detector was developed together with a simple, robust analogue circuit. This circuit converts the original optical signal into an electrical one, compensates slow drifts and offsets, and finally generates a transistor-transistor logic trigger signal as input for the clinical whole-body magnetic resonance scanner. The trigger was successfully applied in mouse experiments.
Insights
A new optical motion detector and analogue circuit were developed to reduce motion artifacts in animal MRI scans. This system successfully triggered magnetic resonance imaging (MRI) acquisitions in mouse experiments, improving image quality.
Area of Science:
- Biomedical Engineering
- Magnetic Resonance Imaging
- Animal Research
Background:
- Clinical MRI systems are increasingly used for animal research.
- Respiratory motion causes significant artifacts in abdominal MRI, particularly in small animals.
- Existing human whole-body MRI detectors lack sensitivity for rodent motion.
Purpose of the Study:
- To develop a sensitive motion detection system for triggering MRI scans in small animals.
- To overcome the limitations of standard MRI detectors for rodent imaging.
Main Methods:
- Development of a sensitive optical motion detector.
- Design of a robust analog circuit to process optical signals.
- Integration of the circuit to generate a transistor-transistor logic (TTL) trigger signal for the MRI scanner.
Main Results:
- The optical motion detector and analog circuit successfully converted optical signals to electrical triggers.
- The system compensated for signal drifts and offsets.
- The developed trigger system was successfully applied in mouse experiments, reducing motion artifacts.
Conclusions:
- A novel optical motion detection system effectively addresses motion artifacts in small animal MRI.
- This technology enables more reliable and higher-quality MRI studies in rodent models.
- The system is compatible with clinical whole-body MRI scanners.
