Low- vs. standard-dose coronary artery calcium scanning

Area of Science:

• Radiology
• Cardiovascular Imaging
• Medical Physics

Background:

• Coronary artery calcium scans (CACS) are vital for cardiovascular risk assessment.
• Optimizing radiation dose in CACS is crucial for patient safety and widespread screening.

Purpose of the Study:

• To evaluate the diagnostic accuracy of CACS performed at radiation doses significantly lower than standard.
• To compare low-dose CACS accuracy against standard-dose CACS and established screening modalities.

Main Methods:

• 102 patients underwent CACS at standard dose (30-80 mAs) and low dose (50% standard mAs) using iterative reconstruction.
• Radiation exposure and Agatston scores were compared between the two dose levels.

Main Results:

• Low-dose CACS demonstrated excellent correlation (r=0.998) with standard-dose CACS for Agatston scores.
• Agreement in cardiovascular risk categories was high (weighted kappa=0.95).
• Low-dose CACS radiation exposure (0.37 mSv) was substantially lower than standard-dose (0.76 mSv) and other screening tools.

Conclusions:

• Low-dose CACS provides accurate cardiovascular risk stratification comparable to standard-dose scans.
• The radiation dose of low-dose CACS is below that of mammography and low-dose lung screening.
• Low-dose CACS exhibits superior interscan reproducibility compared to standard-dose scans.