First experiences with model based iterative reconstructions influence on quantitative plaque volume and intensity measurements in coronary computed tomography angiography

Abstract

Purpose: Investigate the influence of adaptive statistical iterative reconstruction (ASIR) and the model-based IR (Veo) reconstruction algorithm in coronary computed tomography angiography (CCTA) images on quantitative measurements in coronary arteries for plaque volumes and intensities.

Methods: Three patients had three independent dose reduced CCTA performed and reconstructed with 30% ASIR (CTDI_vol at 6.7 mGy), 60% ASIR (CTDI_vol 4.3 mGy) and Veo (CTDI_vol at 1.9 mGy). Coronary plaque analysis was performed for each measured CCTA volumes, plaque burden and intensities.

Results: Plaque volume and plaque burden show a decreasing tendency from ASIR to Veo as median volume for ASIR is 314 mm³ and 337 mm³-252 mm³ for Veo and plaque burden is 42% and 44% for ASIR to 39% for Veo. The lumen and vessel volume decrease slightly from 30% ASIR to 60% ASIR with 498 mm³-391 mm³ for lumen volume and vessel volume from 939 mm³ to 830 mm³. The intensities did not change overall between the different reconstructions for either lumen or plaque.

Conclusion: We found a tendency of decreasing plaque volumes and plaque burden but no change in intensities with the use of low dose Veo CCTA (1.9 mGy) compared to dose reduced ASIR CCTA (6.7 mGy & 4.3 mGy), although more studies are warranted.

Keywords: Cardiac CT; Image quality; Iterative reconstructions; MBIR; Plaque analysis; Veo.