Influence of cardiac hemodynamic parameters on coronary artery opacification with 64-slice computed tomography

Area of Science:

• Cardiovascular Imaging
• Radiology
• Medical Physics

Background:

• Coronary artery opacification is crucial for accurate interpretation in CT angiography.
• Hemodynamic parameters like ejection fraction (EF), stroke volume (SV), heart rate (HR), and cardiac output (CO) may influence image quality.
• Understanding these influences can optimize CT coronary angiography protocols.

Purpose of the Study:

• To assess the impact of EF, SV, HR, and CO on coronary artery opacification.
• To evaluate the relationship between hemodynamic status and contrast enhancement in CT coronary angiography.
• To determine if SV and CO affect image quality metrics like attenuation and contrast-to-noise ratio (CNR).

Main Methods:

• Retrospective analysis of 60 patients undergoing electrocardiography-gated 64-slice CT coronary angiography.
• Calculation of left ventricular EF, SV, and CO using semi-automated software.
• Measurement of attenuation values and calculation of CNR in the proximal right coronary artery (RCA) and left main artery (LMA).

Main Results:

• No significant correlation was found between EF or HR and coronary artery attenuation or CNR.
• A significant negative correlation was observed between SV and both attenuation and CNR in the RCA and LMA.
• A significant negative correlation was also found between CO and both attenuation and CNR in the RCA and LMA, indicating decreased opacification with increased SV and CO.

Conclusions:

• Patient hemodynamic status, specifically stroke volume and cardiac output, significantly influences coronary artery opacification during 64-slice CT.
• Increased SV and CO are associated with decreased coronary artery opacification and reduced image quality.
• These findings suggest potential adjustments in CT angiography protocols based on patient hemodynamics to improve diagnostic accuracy.