Cardiac fiber tracking on super high-resolution CT images: a comparative study

Area of Science:

• Medical Imaging
• Biomedical Engineering
• Cardiovascular Research

Background:

• High-resolution cardiac imaging is crucial for understanding cardiac anatomy and function.
• Refraction-contrast X-ray CT (RCT) offers high soft tissue contrast but requires synchrotron access, limiting its widespread use.
• Microfocus X-ray CT (micro-CT) is a commercially available alternative for detailed imaging.

Purpose of the Study:

• To evaluate the utility of micro-CT for cardiac fiber analysis.
• To quantitatively and objectively compare micro-CT results with those obtained from RCT.
• To assess the accuracy of fiber orientation estimation and fiber tracking using micro-CT.

Main Methods:

• A rabbit heart was scanned using both RCT and micro-CT with a standardized protocol.
• Image-based analysis was performed to compare fiber orientation estimation and fiber tracking.
• Quantitative comparison using correlation coefficients and anatomical validation was conducted.

Main Results:

• Fiber orientations estimated by micro-CT and RCT showed a high resemblance (correlation coefficient of 0.63).
• Fiber tracking from both modalities aligned with known anatomical differences in left ventricular fiber orientation.
• Micro-CT introduced tracking inaccuracies around boundaries due to stitching artifacts from the scanning process.

Conclusions:

• Micro-CT is a viable modality for cardiac fiber analysis, offering comparable results to RCT.
• Further research is needed to address boundary artifacts and refine micro-CT protocols for improved cardiac fiber analysis.
• The findings support the potential of micro-CT as an accessible tool for cardiovascular research.