Eur Radiol (2012) 22:1278–1286 Image analysis Assessment of the MDCT was performed on a dedicated workstation (Extended Brilliance Workstation, Philips Healthcare, Best, The Netherlands). The best systolic and diastolic image phase in the retrospectively gated or pro- spectively triggered CT dataset for coronary assessment was selected. Coronary arteries were assessed according to the 17-segment modified American Heart Association classifi- cation [10] on the axial images (Fig. 1). First, each coronary segment was scored as present or absent. Absent was defined as no visible segment, but sufficient high image quality to exclude non-visibility of other causes or a segment not included in the imaging range. For present segments, the image quality was scored on a three-point scale (1 0 non-diagnostic, 2 0 acceptable, 3 0 good). The criteria for the different scores were formulated as follows: (1) non-diagnostic: segment details not sufficient 1281 visualised to perform diagnostic assessment; (2) acceptable: adequate segment details with limited artefacts; and (3) good: perfect segment details without artefacts. Reasons for non-diagnostic segments were classified as: valve- or ring annuloplasty-related artefacts, or other (e.g. motion, small vessel size, low contrast enhancement and pacemaker lead artefacts). Scoring was performed in consensus by two observers (JH and RB) with 2 years and 5 years experience in CT coronary assessment, respectively. Data analysis Data analysis was restricted to descriptive statistics. Data were presented as means ± standard deviation (SD) for continuous data with a parametric data distribution. Cate- gorical data were presented in total numbers and/or percen- tages. The presence of PHV-related artefacts precluding coronary artery segment assessment was determined for Table 3 Coronary artery segments and valve-related artefacts specified per PHV manufacturer type in other positions PHV position PHV manufacturer PHV type Present segments*/ non-assessable due to PHV artefacts Non-diagnostic coronary segments due to PHV artefacts Mitral Bileaflet Pulmonary Tricuspid * Total number of present segments in Tables 1, 2 and 3 is higher than 1160 owing to multiple assessment of coronary segments in patients with multiple PHVs as the segments are presented for each PHV separately Carbomedics St Jude Duromedics Sorin CE Mitral ring Medtronic Hall Björk–Shiley Sorin Sorin ON-X CE Tricuspid ring Annuplasty ring Tilting disc Bileaflet Bileaflet Annuplasty ring 46/1 51/6 11/4 15/0 62/0 46/0 14/6 16/5 15/1 15/0 15/0 1×LCX segment 13 1×LCX segment 11 1×MO segment 12 1×LCX segment 13 3× MO segment 14 1×LCX segment 11 1×MO segment 12 1×LCX segment 13 1×MO segment 14 None None None 1×RCA segment 2 1×RCA segment 3 1×LAD segment 8 1×MO segment 12 1×LCX segment 13 1×MO segment 14 1×LAD segment 8 1×LCX segment 11 1×MO segment 12 1×LCX segment 13 1×MO segment 14 1×RCA segment 2 None None