Quantifying coronary artery calcification from a contrast-enhanced cardiac computed tomography angiography study

Area of Science:

• Cardiovascular Imaging
• Radiology
• Medical Diagnostics

Background:

• Coronary artery calcium (CAC) quantification is crucial for cardiovascular risk assessment.
• Standard CAC scoring typically requires a separate non-contrast ECG-gated CT scan, increasing radiation dose.
• Contrast-enhanced cardiac computed tomography angiography (CCTA) is primarily used for stenosis assessment.

Purpose of the Study:

• To evaluate the feasibility of quantifying CAC using a single contrast-enhanced CCTA acquisition.
• To establish a correlation between CAC quantified from CCTA and standard CAC scoring methods.
• To develop a correction factor for converting CCTA-derived CAC scores to standard Agatston scores.

Main Methods:

• Patients undergoing both standard CAC and CCTA scans were identified.
• CAC was quantified from CCTA scans (CCTA-CAC) using a novel method based on aortic attenuation.
• A correction factor was derived from a cohort and validated in a separate group to convert CCTA-CAC to standard Agatston score (AS).

Main Results:

• An excellent correlation (r = 0.96) was observed between standard CAC and CCTA-CAC in the derivation cohort.
• A correction factor (slope = 2.74) was derived to convert CCTA-CAC to AS.
• The corrected CCTA-CAC scores showed excellent agreement (kappa = 0.93) with standard CAC in the validation cohort.

Conclusions:

• CAC quantification from a single contrast-enhanced CCTA scan is feasible and highly correlated with standard CAC scoring.
• This approach may offer a way to assess CAC without an additional radiation dose.
• Further multicenter studies are warranted to confirm the universal applicability of this CCTA-based CAC quantification method.