Direct comparison of in vivo versus postmortem second-order motion-compensated cardiac diffusion tensor imaging

Area of Science:

• Cardiovascular Magnetic Resonance Imaging
• Diffusion Tensor Imaging
• Cardiac Anatomy and Physiology

Background:

• Cardiac diffusion tensor imaging (DTI) is crucial for understanding myocardial microstructure.
• Motion artifacts significantly challenge in vivo cardiac DTI accuracy.
• Comparing in vivo and postmortem DTI helps validate imaging techniques.

Purpose of the Study:

• To directly compare in vivo and postmortem second-order motion-compensated spin-echo DTI of the porcine heart.
• To assess the reproducibility and agreement of DTI parameters between live and deceased states.

Main Methods:

• Second-order motion-compensated spin-echo DTI was performed in vivo during systole and repeated postmortem.
• Measurements were taken without repositioning or replanning.
• Key parameters analyzed included helix, transverse, and sheet (E2A) angulation, mean diffusivity, and fractional anisotropy.

Main Results:

• High intraclass correlation coefficients (0.70-0.96) were observed for repeated measurements.
• Good agreement was found between in vivo and postmortem DTI parameters.
• Specific angulation and diffusivity values showed acceptable levels of agreement across the left ventricle.

Conclusions:

• In vivo second-order motion-compensated spin-echo DTI provides parameters that agree well with postmortem imaging.
• The technique effectively suppresses motion-induced signal distortions in cardiac DTI.
• This validates the use of in vivo cardiac DTI for reliable assessment of myocardial microstructure.