Visual estimation of coronary calcium on computed tomography for attenuation correction

Area of Science:

• Cardiology
• Radiology
• Medical Imaging

Background:

• Coronary calcium score (CCS) offers diagnostic and prognostic value for coronary artery disease (CAD).
• Traditional CCS assessment requires a separate computed tomography (CT) scan, adding time and cost.
• Myocardial perfusion imaging (MPI) is often used for CAD assessment.

Purpose of the Study:

• To evaluate the accuracy of visually estimating CCS on routine CT scans used for attenuation correction.
• To assess the inter-reader reproducibility of this visual estimation method.
• To determine if visual CCS estimation can serve as an alternative to dedicated Agatston CCS scans.

Main Methods:

• 250 patients with suspected CAD undergoing single-photon emission computed tomography (SPECT) MPI were included.
• Coronary calcium score (CCS) was calculated using the Agatston method.
• Two independent readers visually estimated CCS on the CT used for attenuation correction, categorizing it into a six-point scale.
• Readers were blinded to the Agatston CCS results.

Main Results:

• The median Agatston CCS was 82 (range 0-7287).
• Visual estimation achieved correct categorization in 60-65% of cases and varied by no more than one category from Agatston CCS in 88-93% of cases.
• High agreement was found between Agatston CCS and visually estimated CCS (intraclass correlation coefficient [ICC] 0.94-0.95).
• Excellent inter-reader reproducibility was observed for visual CCS estimation (ICC 0.96).

Conclusions:

• Visual estimation of CCS on CT attenuation correction scans is accurate and highly reproducible.
• This method provides a reliable alternative for assessing coronary atherosclerosis when a dedicated Agatston CCS is not feasible.
• Routine CT scans can be utilized for preliminary CCS assessment, potentially streamlining CAD evaluation.