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Updated: Jul 4, 2026
In Vivo Quantitative Assessment of Myocardial Structure, Function, Perfusion and Viability Using Cardiac Micro-computed Tomography
Published on: February 16, 2016
Quantification of myocardial perfusion by contrast-enhanced 64-MDCT: characterization of ischemic myocardium
Michinobu Nagao1, Hiroshi Matsuoka, Hideo Kawakami
1Department of Radiology, Prefectural Ehime Imabari Hospital, Ishii-cho 4-5-5, Imabari-city, Ehime 794-0006, Japan.
Insights
Myocardial ischemia is characterized by reduced subendocardial perfusion during systole, not diastole. This finding using computed tomography angiography (CTA) helps identify ischemic heart segments.
Area of Science:
- Cardiovascular imaging
- Medical diagnostics
- Myocardial perfusion assessment
Background:
- Assessing hemodynamic changes in ischemic cardiac segments at rest using CT is an emerging area.
- Hypothesized that subendocardial perfusion variations during the cardiac cycle correlate with ischemia.
- Previous studies have not fully explored dynamic perfusion changes in ischemic myocardium using CT.
Purpose of the Study:
- To investigate myocardial perfusion in ischemic segments using contrast-enhanced 64-MDCT.
- To evaluate the relationship between cardiac cycle variations and ischemic appearances.
- To establish a CT-based method for assessing dynamic myocardial perfusion.
Main Methods:
- 34 patients with suspected coronary artery disease underwent cardiac MDCT and stress/rest Thallium-201 myocardial perfusion scintigraphy (MPS).
- 2D cardiac images (diastolic and systolic phases) were reconstructed from CTA data.
- Subendocardial intensity (Hounsfield units) measured perfusion; systolic/diastolic perfusion ratios calculated and compared between ischemic and non-ischemic segments using MPS as a reference.
Main Results:
- Ischemic segments showed significantly lower systolic perfusion compared to non-ischemic segments (15/17 segments).
- The difference between systolic and diastolic perfusion was significantly lower in ischemic segments (14/17 segments).
- No significant difference in diastolic perfusion was observed between ischemic and non-ischemic segments (15/17 segments).
Conclusions:
- A distinct pattern of subendocardial hypoperfusion during systole with normal perfusion during diastole characterizes ischemic myocardium.
- Contrast-enhanced 64-MDCT can identify dynamic perfusion deficits in ischemic cardiac segments.
- Findings suggest CTA can assess hemodynamic changes related to myocardial ischemia.
Objective:
Assessment of hemodynamic changes in ischemic cardiac segments at rest using CT has yet to be performed. We hypothesized that variations in subendocardial perfusion during the cardiac cycle might be related to the appearances of ischemia. The purpose of this study was to investigate myocardial perfusion in ischemic segments using contrast-enhanced 64-MDCT.
Subjects And Methods:
We performed cardiac MDCT at rest and stress/rest (201)Tl myocardial perfusion scintigraphy (MPS) in 34 patients with suspected coronary artery disease. We reconstructed 2D long- and short-axis cardiac images in diastolic and systolic phases using raw data from coronary CT angiography. The attenuation value (in Hounsfield units) in the myocardium was used as an estimate of myocardial perfusion. We measured the subendocardial intensity of 17 segments according to the American Heart Association classification. Systolic perfusion or diastolic perfusion was calculated by dividing the subendocardial intensity at systole or diastole, respectively, for each segment by the mean value across all segments for each patient. We used stress/rest MPS to evaluate the variation in myocardial perfusion at systole and diastole for the segments diagnosed as ischemic or nonischemic.
Results:
Systolic perfusion for ischemic segments was significantly lower than that for nonischemic segments in 15 of 17 segments. The difference between systolic perfusion and diastolic perfusion in ischemic segments was significantly lower than that in nonischemic segments (14 of 17 segments). There was no significant difference in diastolic perfusion between ischemic and nonischemic segments (15 of 17 segments).
Conclusion:
Our results suggest that a pattern of subendocardial hypoperfusion at systole and normal perfusion at diastole characterizes ischemic myocardium.
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