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Updated: Aug 29, 2026
Quantitative Micro-CT Analysis of Aortopathy in a Mouse Model of β-aminopropionitrile-induced Aortic Aneurysm and Dissection
Published on: July 16, 2018
Relationship between arterial diameter and perfused tissue volume in myocardial microcirculation: a micro-CT-based
Nasser M Malyar1, Mario Gössl, Patricia E Beighley
1Dept. of Physiology and Biomedical Engineering, Alfred 2-409, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA.
Insights
The study reveals that smaller coronary arterioles perfuse less myocardial tissue than larger ones, with perfusion volumes directly related to arteriole size. This finding helps understand blood flow distribution in the heart muscle.
Area of Science:
- Cardiovascular Physiology
- Microcirculation Research
- Medical Imaging Analysis
Background:
- Epicardial coronary artery diameter predicts myocardial tissue perfusion.
- The relationship between intramyocardial arteriole diameter and perfusion volume is not well understood.
Purpose of the Study:
- To investigate the correlation between coronary arteriole diameter and the myocardial volume they perfuse.
- To quantify nonperfused myocardial volume following arteriole embolization.
Main Methods:
- Injected microspheres of varying sizes (10, 30, 100 microm) into coronary arteries of anesthetized pigs.
- Used micro-CT scanning to create 3D images of embolized myocardial tissue.
- Analyzed images to determine the volume of perfusion defects caused by embolized arterioles.
Main Results:
- Individual myocardial perfusion defects (volumes perfused by single arterioles) were measured: 0.0004 mm³ (10 microm), 0.02 mm³ (30 microm), and 0.62 mm³ (100 microm).
- The number of perfusion defects was inversely related to microsphere dose, suggesting random distribution and clustering.
Conclusions:
- Coronary arteriole diameter is a key determinant of myocardial perfusion volume at the microcirculatory level.
- Findings provide quantitative data on microvascular perfusion territories, relevant for understanding myocardial blood flow and ischemia.
Abstract:
The volume of myocardial tissue that is perfused by an epicardial coronary artery has been shown to be predictably related to the diameter of the epicardial arterial lumen. However, to what extent the intramyocardial microvasculature follows the epicardial rules remains unclear. To explore the relationship between the diameter of coronary arterioles and their subsequent perfused myocardial volumes, we quantified the volume of nonperfused myocardium resulting from an embolized arteriole of a certain diameter. We injected a single dose of microspheres selected from one of nine possible microsphere combinations (10, 30, and 100 microm diameter, each at three possible doses) into the left anterior descending coronary and/or left circumflex arteries of seven anesthetized pigs. At postmortem, the coronary arteries were infused with a radiopaque silicon polymer. Embolized myocardium (1 cm(3)) was scanned with a microcomputerized tomography scanner and resulted in three-dimensional images that consisted of 20 microm/side cubic voxels and a subvolume of the specimen with 4 microm/side cubic voxels. Image analysis provided the number and volumes of myocardial perfusion defects for each size and dose of microspheres. The smallest individual myocardial perfusion defects, which correspond to the volume of myocardium perfused by a single embolized arteriole, were found to be 0.0004 +/- 0.0002, 0.02 +/- 0.004, and 0.62 +/- 0.099 mm(3) for the 10-, 30-, and 100-microm microspheres, respectively. The number of myocardial perfusion defects in the embolized myocardium was inversely related to the dose of the injected microspheres. This reflects a clustering behavior that is consistent with a random distribution process of the individual embolized perfusion defects.
