Influence of hemodynamic parameters on coronary artery attenuation with 320-detector coronary CT angiography
Nobuo Tomizawa1, Shuhei Komatsu, Masaaki Akahane
1Department of Radiology, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan. tomizawa-tky@umin.ac.jp
Insights
High cardiac output and larger end-diastolic volume reduce coronary CT angiography contrast enhancement. This finding is crucial for optimizing contrast agent use in 320-detector CT scans.
Area of Science:
- Cardiovascular Imaging
- Radiology
- Medical Physics
Background:
- Coronary CT angiography (CCTA) is vital for diagnosing coronary artery disease.
- Optimizing contrast enhancement in CCTA is essential for accurate image interpretation.
- 320-detector CT scanners offer improved temporal resolution for cardiac imaging.
Purpose of the Study:
- To investigate the relationship between cardiac output, end-diastolic volume, and contrast enhancement in CCTA.
- To determine how hemodynamic factors influence image quality in 320-detector CT angiography.
- To identify patient characteristics associated with suboptimal contrast enhancement.
Main Methods:
- 38 patients underwent CCTA using a 320-detector CT scanner.
- Ascending aorta attenuation was measured to assess contrast enhancement.
- Cardiac output, end-diastolic volume (EDV), and stroke volume were measured by echocardiography.
- Normalized EDV (EDV/BSA) and total injected blood volume (TIV) were calculated.
Main Results:
- A negative correlation was observed between aortic attenuation and cardiac output (r = -0.44, P = 0.0053).
- A stronger negative correlation existed between aortic attenuation and TIV (r = -0.52, P = 0.0007).
- A negative correlation was found between aortic attenuation and EDV/BSA (r = -0.45, P = 0.0039).
Conclusions:
- Higher cardiac output is associated with decreased contrast enhancement in CCTA using 320-detector CT.
- Patients with larger end-diastolic volume normalized to body surface area may exhibit reduced contrast enhancement.
- These findings suggest that hemodynamic parameters should be considered for optimizing contrast administration in CCTA.
Objectives:
To investigate the relationship between cardiac output, end diastolic volume and the contrast enhancement in coronary CT angiography using 320-detector CT.
Materials And Methods:
A total of 38 patients underwent coronary CT angiography by using a 320-detector CT scanner (detector configuration, 320 × 0.5mm). The attenuation value of the ascending aorta at the level of the orifice of the left main trunk was measured. The cardiac output (CO), end diastolic volume (EDV) and stroke volume (SV) were measured by echocardiography. The EDV was normalized to the body surface area (BSA). The total blood volume injected from the left ventricle from the beginning of the contrast agent injection to the time of image acquisition was determined to be the total injected blood volume (TIV), which is a product of SV and the number of heart beats from the initiation of contrast agent injection to the scan.
Results:
There was a negative correlation between the attenuation of the ascending aorta and CO (r = -0.44, P = 0.0053). However, the negative correlation between the attenuation of the ascending aorta and TIV was stronger (r = -0.52, P = 0.0007). There was a negative correlation between the attenuation of the ascending aorta and EDV/BSA (r = -0.45, P = 0.0039).
Conclusion:
In 320-detector CT, contrast enhancement in CCTA with a lesser amount of contrast medium decreases when cardiac output is high. Patients with larger EDV/BSA may also show decreased attenuation.
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