Optimization of Computed Tomography Coronary Angiography for Improved Plaque Detection

Area of Science:

• Medical Imaging
• Radiology
• Cardiovascular Imaging

Background:

• Computed tomography coronary angiography (CTCA) is crucial for visualizing coronary artery disease.
• Accurate assessment of coronary vessel wall thickness is essential for risk stratification.
• Optimizing CTCA parameters is necessary to enhance image quality and diagnostic accuracy.

Purpose of the Study:

• To determine optimal computed tomography (CT) parameters for improved visualization of the coronary artery wall.
• To evaluate the trade-offs between spatial resolution, contrast resolution, and vessel wall thickness accuracy in CTCA.
• To identify specific x-ray tube current and voltage settings for enhanced coronary wall imaging.

Main Methods:

• A coronary plaque phantom was utilized for standardized imaging acquisition.
• Scans were performed on a wide-volume CT scanner across varying x-ray tube currents (mA) and voltages (kVp).
• Key imaging metrics including spatial resolution, contrast resolution, and vessel wall thickness were quantitatively assessed.

Main Results:

• Spatial resolution decreased significantly with increasing x-ray tube current.
• Contrast-to-noise ratio (CNR) demonstrated a significant increase at higher currents.
• Optimal accuracy for coronary wall thickness measurements was achieved at intermediate currents (300-400 mA) with specific voltage settings (80-135 kVp).

Conclusions:

• Higher CT currents lead to increased focal spot blur, reducing spatial resolution.
• Increased CNR at higher currents is attributed to reduced quantum noise.
• Accurate coronary wall thickness measurement requires a balance between achieving optimal spatial resolution and acceptable CNR, often necessitating intermediate imaging parameters.