Contrast-enhanced computed tomography to measure aortic calcium volume score

In clinical practice, calcium scoring is typically measured only in the aortic valve region. However, calcium accumulation in other areas, such as the aortic arch, can pose risks during transcatheter aortic valve implantation (TAVI). Dislodged plaque due to catheter manipulation may lead to cerebrovascular events. Establishing a method to assess calcium distribution in these regions could help to determine when protective measures in the carotid arteries are necessary. This study aims to validate a calcium segmentation technique in contrast-enhanced CT angiography (CTA) and establish a method for regional calcium quantification, as no standardized approach currently exists. Additionally, it assesses the correlation and reproducibility of calcium scores obtained from unenhanced and contrast-enhanced CT images using the Agatston method and calcium volume to validate the proposed methodology. A dataset of 55 patients with both contrast-enhanced and unenhanced images was used, where calcium was segmented and scores were calculated for each image type. Notably, the threshold for the segmentation method in contrast-enhanced images was found to be image-dependent. Additionally, contrast-enhanced images were reconstructed to ensure the same spacing between slices as their non-contrast counterparts. The results showed high Pearson r 2 correlation values (0.87 and 0.89) between calcium scores in contrast-enhanced and unenhanced images for the Agatston and volume metrics, respectively, although the Agatston method exhibited greater variability. Additionally, calcium volume in various aortic regions was calculated, with the arch showing the most significant accumulation of calcium. This study demonstrates the feasibility of using calcium scoring in contrast-enhanced imaging with an image-dependent threshold. Furthermore, assessing calcium in other aortic regions is proposed as a risk factor prior to TAVI intervention.