Three-dimensional Cardiomyocytes Structure Revealed By Diffusion Tensor Imaging and Its Validation Using a...

Area of Science:

• Biomedical Imaging
• Cardiovascular Research
• Histology

Background:

• Cardiovascular diseases alter myocardial microstructure.
• Accurate characterization of cardiomyocyte architecture is crucial for understanding heart function and disease.
• Existing methods for assessing cardiomyocyte orientation can be invasive or lack 3D resolution.

Purpose of the Study:

• To characterize the microstructural response of the myocardium to cardiovascular disease using diffusion tensor imaging (DTI).
• To validate DTI findings with intact, three-dimensional (3D) histology using a tissue-clearing technique.
• To assess the accuracy of DTI in quantifying cardiomyocyte orientation and transmurality.

Main Methods:

• Diffusion tensor imaging (DTI) was performed on fixed ex-vivo mouse hearts (normal and ischemic heart failure models).
• Hearts were processed using a tissue-clearing technique for intact 3D histological analysis.
• Cardiomyocyte orientation, helix angle (HA), and global HA transmurality (HAT) were quantified and compared between DTI and 3D histology.

Main Results:

• DTI successfully mapped cardiomyocyte orientation and was validated by 3D histology.
• Global HAT was significantly reduced in the ischemic heart failure group compared to controls (p < 0.001).
• Strong correlations were observed between DTI and 3D histology for cardiomyocyte orientation assessment (R²=0.803 per-sample, R²=0.872 per-segment).

Conclusions:

• DTI is a capable and accurate tool for mapping cardiomyocyte orientation in the myocardium.
• The study demonstrates the potential of DTI for noninvasive characterization of cardiac microstructure in disease states.
• This approach provides valuable insights into the architectural changes associated with cardiovascular disease.