Eur Radiol (2012) 22:1271–1277 DOI 10.1007/s00330-011-2358-1 CARDIAC Prospective ECG triggering reduces prosthetic heart valve-induced artefacts compared with retrospective ECG gating on 256-slice CT Petr Symersky & Jesse Habets & Paul Westers & Bas A. J. M. de Mol & Mathias Prokop & Ricardo P. J. Budde Received: 24 July 2011 / Revised: 20 November 2011 / Accepted: 22 November 2011 / Published online: 30 December 2011 # The Author(s) 2011. This article is published with open access at Springerlink.com Abstract Objectives Multidetector computed tomography (MDCT) has diagnostic value for the evaluation of prosthetic heart valve (PHV) dysfunction but it is hampered by artefacts. We hypothesised that image acquisition using prospective trig- gering instead of retrospective gating would reduce artefacts related to pulsating PHV. Methods In a pulsatile in vitro model, a mono- and bileaflet PHV were imaged using 256 MDCT at 60, 75 and 90 beats per minute (BPM) with either retrospective gating (120 kV, 600 mAs, pitch 0.2, CTDIvol 39.8 mGy) or prospective triggering (120 kV, 200 mAs, CTDIvol 13.3 mGy). Two thresholds (>175 and <−45HU), derived from the density P. Symersky (*) : B. A. J. M. de Mol Department of Cardiothoracic Surgery, Academic Medical Center, Meibergdreef 9, 1105 AZ Amsterdam, the Netherlands e-mail: psymersky@gmail.com J. Habets : R. P. J. Budde Department of Radiology, University Medical Center Utrecht, Utrecht, the Netherlands P. Westers Department of Biostatistics, Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, the Netherlands B. A. J. M. de Mol Department of Biomedical Engineering, University of Technology Eindhoven, Eindhoven, the Netherlands M. Prokop Department of Radiology, Radboud University Nijmegen Medical Center, Nijmegen, the Netherlands of surrounding structures, were used for quantification of hyper- and hypodense artefacts. Image noise and artefacts were compared between protocols. Results Prospective triggering reduced hyperdense artefacts for both valves at every BPM (P 0 0.001 all comparisons). Hypodense artefacts were reduced for the monoleaflet valve at 60 (P 0 0.009), 75 (P 0 0.016) and 90 BPM (P 0 0.001), and for the bileaflet valves at 60 (P 0 0.001), 90 (P 0 0.001) but not at 75 BPM (P 0 0.6). Prospective triggering reduced image noise at 60 (P 0 0.001) and 75 (P < 0.03) but not at 90 BPM. Conclusions Compared with retrospective gating, prospec- tive triggering reduced most artefacts related to pulsating PHV in vitro. Key Points Computed tomographic images are often degraded by prosthetic heart valve-induced artefacts Prospective triggering reduces prosthetic heart valve- induced artefacts in vitro Artefact reduction at 90 beats per minute occurs without image noise reduction Prospective triggering may improve CT image quality of moving hyperdense structures Keywords Computed tomography . Heart valve prosthesis . Cardiac-gated imaging techniques . Artefacts . Cardiovascular model Introduction Electrocardiography (ECG)-gated multidetector computed tomography (MDCT) can identify the morphological sub- strates of prosthetic heart valve (PHV) dysfunction [1–4].