Technical note: Exploring the detectability of coronary calcification using ultra-high-resolution...

Area of Science:

• Medical Imaging
• Radiology
• Cardiovascular Imaging

Background:

• Coronary calcification is a key indicator of coronary artery disease (CAD).
• A zero coronary calcification score indicates a lower cardiac event risk.
• Limited spatial resolution in conventional CT can lead to missed small calcifications, causing false-negative scores.

Purpose of the Study:

• To compare the detection limits of coronary calcification between ultra-high-resolution (UHR) photon-counting-detector CT (PCD-CT) and conventional energy-integrating-detector CT (EID-CT).

Main Methods:

• Eggshell fragments (0.4-0.8 mm) mimicking calcifications were scanned on PCD-CT (UHR mode) and EID-CT.
• Images were reconstructed using matched radiation doses and varying kernels/algorithms.
• In vivo patient scans from PCD-CT (UHR) were compared to clinical EID-CT exams.

Main Results:

• PCD-CT visualized all calcified fragments, while EID-CT missed fragments below 0.6 mm.
• Sharper EID-CT kernels improved visibility but caused boundary distortion.
• Small calcifications missed on EID-CT were detected on PCD-CT in patient cases.

Conclusions:

• PCD-CT in UHR mode offers superior spatial resolution for detecting small coronary calcifications.
• This improved detectability enhances the accuracy of cardiac event risk assessment.
• PCD-CT demonstrates higher sensitivity for small calcifications than conventional EID-CT at equivalent radiation doses.