Quantification of Coronary Calcification using High-Resolution Photon-Counting-Detector CT and an Image Domain...

Area of Science:

• Medical Imaging
• Radiology
• Cardiovascular Imaging

Background:

• Coronary artery calcification (CAC) is a key marker for coronary heart disease.
• Accurate volume quantification of CAC, particularly small calcifications, is difficult with conventional computed tomography (CT) due to calcium blooming artifacts from limited spatial resolution.

Purpose of the Study:

• To evaluate the accuracy of coronary calcification volume quantification using a clinical photon-counting detector (PCD) CT scanner compared to a conventional energy-integrating detector (EID) CT scanner.
• To assess the impact of improved spatial resolution and denoising algorithms on reducing calcium blooming artifacts in PCD-CT.

Main Methods:

• Ex-vivo coronary specimens were scanned using both clinical PCD-CT and EID-CT at identical radiation doses and tube potential.
• PCD-CT images were reconstructed with a sharper kernel and denoised to match EID-CT noise levels.
• Calcification volumes were segmented and compared against micro-CT imaging as the reference standard.

Main Results:

• PCD-CT demonstrated reduced calcium blooming artifacts compared to EID-CT.
• Volume overestimation of micro-CT volumes was significantly lower for PCD-CT (9 ± 12%) than for EID-CT (24 ± 18%).
• The current PCD-CT system showed superior volume quantification accuracy compared to an earlier investigational PCD-CT scanner.

Conclusions:

• Clinical PCD-CT offers improved accuracy for coronary calcification volume quantification over conventional EID-CT.
• PCD-CT technology, with enhanced resolution and denoising, effectively mitigates blooming artifacts, leading to more precise assessments of coronary artery calcification.