Eur Radiol (2012) 22:1278–1286 1283 Fig. 4 St Jude bileaflet Prosthetic Heart Valve (PHV) in the aortic position, which causes PHV-related artefacts in RCA segment 1 316/1160 (27%) image quality was good. The reasons for non-diagnostic image quality were PHV-related artefacts (n 0 43; 14%), motion (n 0 60 segments; 20%), vessel size (n 0 192; 63%); and pacemaker artefacts (n 0 11; 4%) (Fig. 2). In patients with more than one PHV implanted, no coronary segments were non-assessable owing to arte- facts originating from both valves. None of the biological PHVs (0/21; 0%) and annulo- plasty rings (0/5; 0%), and none of the ON-X (0/6; 0%) and Medtronic Hall (0/12; 0%) mechanical PHVs caused artefacts prohibiting coronary assessment. Fig. 5 a Björk–Shiley tilting disc Prosthetic Heart Valve (PHV) in the mitral position, which causes PHV-related artefacts in LCX. b Medtronic Hall tilting disc PHV in the mitral position, which causes no PHV-related artefacts in LCX In the aortic position, St Jude (2/8; 25%) and Sorin (3/5; 60%) bileaflet PHVs caused artefacts prohibiting coronary assessment, mainly of the proximal right coronary artery (RCA). The Björk–Shiley (n0 3; 100%) and Sorin tilting disc PHVs (n0 1; 100%) caused severe artefacts in RCA segments. Moreover, the Björk–Shiley tilting disc also caused artefacts in the left circumflex (LCX) and obtuse marginal (MO) branches (Table 2). The commonly implanted PHVs (Carbo- medics bileaflet (n0 21; 0%) and Medtronic Hall tilting disc (n0 9; 0%) demonstrated no PHV-related artefacts in the aortic position (Tables 1 and 2). Figures 3 and 4 illustrate aortic PHVs with and without PHV-related artefacts in the RCA. In the mitral position, Carbomedics (1/3; 33%), St Jude (3/4; 75%) and the Duromedics (1/1; 100%) bileaflet PHVs caused artefacts prohibiting assessment of at least one coro- nary segment in the LCX and MO branches. Both Björk– Shiley and the Sorin tilting disc PHVs caused severe artefacts in LCX and MO segments. The Björk–Shiley tilting disc also caused severe artefacts in RCA segments. Affected segments are detailed in Table 3. Figure 5 illustrates mitral PHVs with and without artefacts in the LCX. In the pulmonary position, the Sorin bileaflet PHV (n0 1; 100%) demonstrated PHV- related artefacts in RCA segment 2. In the tricuspid position, ON-X bileaflet PHV (n 0 1) and tricuspid annuplasty ring (n0 1) showed no PHV-related artefacts (Table 3). PHV related artefacts in different imaging phases In all patients, coronary artery segments were assessed in the best systolic and diastolic imaging phase. In the aortic posi- tion, four patients (5%) demonstrated PHV-related artefacts precluding diagnostic coronary assessment of RCA segment 1 only in diastolic (n0 2; 50%) or systolic (n0 2; 50%) phase. In the mitral position, one patient (6%) had only PHV-related artefacts in the diastolic phase in the LCX and MO branches.