16 Effect of a calcium deblooming algorithm on the accuracy of coronary computed tomography angiography

Introduction Coronary artery calcification is a significant contributor to reduced accuracy of coronary computed tomographic angiography (CTA) in the assessment of coronary artery disease severity. The aim of the current study is to assess the impact of a prototype calcium deblooming algorithm on the diagnostic accuracy of CTA. Methods 40 patients referred for invasive catheter angiography underwent CTA and invasive catheter angiography. CTA studies were read with and without the deblooming algorithm blinded to the invasive coronary angiogram findings. Sensitivity, specificity, accuracy, positive predictive value and negative predictive value for the detection of stenosis ≥50% were evaluated using quantitative coronary angiography as the reference standard. Results All studies were diagnostic with 581 segments available for evaluation. Image score was 3.64±0.72 with CTA DEBLOOM , versus 3.56±0.72 with CTASTAND (p=0.38). CTADEBLOOM had significantly less calcium blooming artifact than CTASTAND (12.5% vs. 47.5%, p=0.001). The Sensitivity/Specificity/PPV/NPV/Accuracy were 64.4/85.2/27.6/96.5/83.5 for CTA DEBLOOM and 75.0/81.6/25.8/97.5/81.1 for CTASTAND. CTA DEBLOOM specificity was significantly higher than CTASTAND (85.2% vs. 81.6%, p=0.017), with no difference between the algorithms in sensitivity (p=0.22), or accuracy (p= 0.09). Interobserver agreement was fair with both techniques (CTA DEBLOOM k= 0.38, CTASTAND k= 0.37). Conclusion Coronary calcification deblooming using a prototype post-processing algorithm is feasible and significantly reduces calcium blooming with an improvement of the specificity of the CTA exam.