Impact of dual energy cardiac CT for metal artefact reduction post aortic valve replacement. Issue 129 (August 2020)

• Record Type: Journal Article
• Authors: Schwartz, Fides Regina; Tailor, Tina; Gaca, Jeffrey G.; Kiefer, Todd; Harrison, Kevin; Hughes, G. Chad; Ramirez-Giraldo, Juan-Carlos; Marin, Daniele; Hurwitz, Lynne M.
• Is Part Of: European journal of radiology. Issue 129(2020)
• Publication Date: 2020-08
• Subjects: BMI Body Mass Index -- bpm beats per minute -- CNR contrast-to-noise ratio -- COV coefficient of variance -- CPR curved planar reconstruction -- DE dual-energy -- DFOV displayed field of view -- ECG electrocardiogram -- keV kiloelectron volt -- kVp kilovolt peak -- mL milliliter -- sec second -- MDCT Multidetector computed tomography -- SAVR surgical aortic valve replacement -- SE single-energy -- SD standard deviation -- SFOV scan field of view -- SNR signal-to-noise ratio -- TAVR transcatheter aortic valve replacement -- VC valve coaptation -- VIS valve insertion site -- VMI Virtual monoenergetic images; Cardiac computed tomography -- Aortic valve replacement -- Dual-energy computed tomography -- Metal artefact reduction; Medical radiology -- Periodicals; Radiology -- Periodicals; Radiologie médicale -- Périodiques; Medical radiology; Periodicals; 616.075705
• DOI: 10.1016/j.ejrad.2020.109135
• Languages: English
• ISSNs: 0720-048X

Abstract

Highlights: Dual-energy cardiac CT can reduce metal artefact from aortic valve replacements by up to 17 %. Blended dual-energy reconstructions provide similar temporal resolution to single-energy CT. DE high keV monoenergetic renderings provide best metal artefact reduction. DE low keV monoenergetic renderings provide highest contrast opacification and homogeneity. Combined reading of DE blended and monoenergetic renderings can improve radiology workflows. Abstract: Purpose: Assess image quality of dual-energy (DE) and single-energy (SE) cardiac multi-detector computed tomographic (MDCT) post aortic valve replacement (AVR) on a dual source MDCT scanner. Methods: Eighty patients with cardiac MDCT acquisitions (ECG gated, dual-source) post-surgical and transcatheter AVR were retrospectively identified. Forty DE (cohort 1) and 40 SE acquisitions (cohort 2; 100 or 120 kVp) were reviewed. Metal artefact at valve coaptation (VC) and valve insertion site (VIS), and contrast enhancement were assessed. Valve leaflet edge definition was graded on a 4-point scale by three radiologists. Results: The mean percentage valve area obscured by metal artifact differed between the cohorts; cohort 1 DE blended, high keV and low keV: 14.8 %, 11.1 % and 17.8 % at VC and 16.4 %, 13 %, 20.4 % at VIS respectively. Cohort 2: 25.8 % and 33.6 % (VC and VIS); each DE reconstruction vs SE: P < 0.0001. Average contrast opacification and coefficient of variance for cohort 1: 562.9 ± 144.7, 281.1 ± 60.3 and 1132.7 ± 300.8 Hounsfield Units (HU) and 9.6 %, 10 % and 8.9 %. For cohort 2: 437.2 ± 119.2 HU and 10.8 % (P < 0.01). Average leaflet edge definition cohort 1: 2.3 ± 0.4, 2.7 ± 0.2 and 2.3 ± 0.2, and cohort 2: 2.9 ± 0.2. Conclusion: DE high keV renderings can result in up to 17.2 % less metal artefact compared to standard SE acquisition for cardiac CT. Contrast opacification and homogeneity is higher for DE blended and low keV renderings compared to SE acquisition with leaflet visibility preferred for low keV and blended DE renderings.