Abstract 14964: Photon Counting Computed Tomography for Aortic Valve Calcium Scoring in Contrast Enhanced Datasets of the Heart

Abstract

Introduction: The prognostic value of aortic valve calcification prior to transcatheter aortic valve replacement (TAVR) is well established. Its reliable quantification requires a non-contrast computed tomography (CT) of the heart (‘true non contrast’, TNC) which in this cohort is not regularly performed at all centers. Photon Counting Detector CT (PCD-CT) permits the routine derivation of ‘virtual non-contrast’ (VNC) and ‘virtual non-iodine’ (VNI) series from CT Angiography (CTA) acquisitions due to its intrinsic spectral sensitivity. These might render separate non-contrast acquisitions unnecessary. Hypothesis: We hypothetized that quantification of aortic valve calcification of VNC/ VNI series derived from CTA scans is feasable and correlates with calcium scores of TNC series. Methods: 45 consecutive patients underwent pre TAVR CT on a novel PCD-CT (NAEOTOM Alpha, Siemens Healthineers, Erlangen, Germany) comprising a non-contrast CT of the heart, followed by a CTA of the heart, aorta, and iliac arteries. VNC series were derived from CTA acquisitions and two readers independently quantified aortic valve calcium scores (Agaston score) and calcium volumes on VNC-, VNI- and TNC-series. Results: A total of 41 patients (41.46% female) were included in the study. In comparison with aortic valve calcium scores and volume scores derived from TNC series (i.e., 2800[2075-3681] vs. 2206[1645-2894] mm3), those derived from VNC (i.e., 752[390-1357] vs. 653.3[319.5-1052.3] mm3) and VNI (i.e., 1986[1270-3278] vs. 1515[971-2480] mm3) series were consistently lower but correlation was excellent for both, i.e., calcium and volume score, respectively (r’s: 0.96 and 0.96 for VNC; r’s: 0.92 and 0.91 for VNI, p< 0.05). Conclusions: Our initial patient experience with TAVR planning CT on a novel PCD-CT showed signficant correlation of aortic valve calcium scores and volumes derived from VNC and VNI series, as compared with those derived from TNC series, thus rendering non-contrast acquisitions for TAVR planning redundant.