Micro-CT with respiratory and cardiac gating

Area of Science:

• Medical imaging
• Biomedical engineering
• X-ray physics

Background:

• Cardiopulmonary imaging in rodents via micro-computed tomography (CT) is hindered by cardiac and pulmonary motion.
• Limited fluence rates from micro-focus X-ray tubes in commercial systems pose significant challenges.
• Achieving high-resolution images requires addressing both spatial and temporal scales impacting photon requirements.

Purpose of the Study:

• To develop an optimized micro-CT system for high-resolution rodent cardiopulmonary imaging.
• To overcome limitations of motion blur and low photon flux in micro-CT.
• To achieve isotropic spatial resolution for detailed anatomical visualization.

Main Methods:

• Utilized a system with a fixed X-ray tube/detector and a rotating specimen.
• Employed a large focal spot X-ray tube for high fluence rates and short exposure times (10 ms).
• Optimized geometry to synchronize focal spot blur with detector pitch and gating reproducibility, synchronized to cardiac and breathing motion.

Main Results:

• Achieved isotropic spatial resolution of 100 micrometers.
• Obtained a detector fluence rate 250 times higher than conventional micro-CT systems.
• Successfully minimized motion blur through short, synchronized exposures.
• Validated system performance in vivo for cardiopulmonary structures in C57BL/6 mice.

Conclusions:

• The developed micro-CT system enables high-resolution, motion-minimized cardiopulmonary imaging in rodents.
• Integration of a bright X-ray source with motion synchronization significantly enhances imaging capabilities.
• This technology offers valuable insights into rodent cardiopulmonary structures for research.