Myocardial capillary permeability to iohexol. Evaluation with fast x-ray computed tomography

Area of Science:

• Cardiovascular imaging
• Medical physics
• Pharmacology

Background:

• Assessing myocardial capillary integrity is crucial for understanding cardiac health.
• Current methods for measuring capillary permeability can be invasive or complex.
• Fast x-ray computed tomography (CT) offers a potential non-invasive imaging solution.

Purpose of the Study:

• To evaluate the accuracy and sensitivity of fast x-ray CT for estimating myocardial capillary permeability to iohexol.
• To establish a quantitative method for assessing capillary integrity in the myocardium.

Main Methods:

• Anesthetized pigs underwent coronary infusion of adenosine and aortic root injection of iohexol.
• CT images were analyzed to compute myocardial perfusion (F) and capillary extraction factor (E).
• Permeability-surface area product (PS) was calculated; accuracy validated against dual-dilution curves (DDC) and bradykinin infusion.

Main Results:

• CT-derived PS values showed good correlation with DDC-obtained PS values across different iohexol concentrations.
• The concentration of iohexol had minimal impact on the calculated PS values (P > 0.1).
• Bradykinin infusion demonstrated a significant correlation (r = 0.845), indicating good sensitivity.

Conclusions:

• Fast x-ray CT provides accurate and sensitive estimations of myocardial capillary permeability.
• The method is reliable across varying iohexol concentrations.
• This CT technique holds promise for quantitative assessment of capillary integrity in cardiovascular research.