1284 Fig. 6 Cardiac valvular anatomy with a St Jude Prosthetic Heart Valve (PHV) in the mitral position. The illustration demonstrates the close relationship between the LCX and the mitral PHV In summary, PHV-related artefacts were present in RCA segments (1, 2 and 3), left anterior descending artery (LAD) segment 8, LCX segments (11 and 13), and MO branches (12 and 14). The close relationship between RCA and aortic PHV, and LCX and mitral PHV is illustrated in Fig. 6. The assessment of the remaining coronary segments (including the left main branch, Fig. 7) was not disturbed by PHV- related artefacts (Fig. 1, Tables 2 and 3). Discussion The principle findings of our study are: (1) the diagnostic assessment of most coronary artery segments in patients with PHVs was not hampered by PHV-related artefacts, (2) Björk– Shiley tilting disc PHVs, Sorin tilting disc PHVs and Duro- medics bileaflet PHVs precluded complete diagnostic assess- ment of coronary artery segments; and (3) ON-X and Medtronic Hall PHVs, biological PHVs and annuloplasty rings never hampered coronary artery assessment by MDCT. Fig. 7 Carbomedics bileaflet Prosthetic Heart Valve (PHV) in the aortic position, which causes no PHV-related artefacts in the LM branch Eur Radiol (2012) 22:1278–1286 The PHV-related artefacts on MDCT images seem to be more dependent on PHV composition than on the PHV design (bileaflet, tilting disc and biological valves) (Table 4) [8, 9]. As far as the material of the PHV is concerned our study showed notable differences. Björk–Shiley and Sorin tilting disc PHVs as well as Duromedics bileaflet PHVs demonstrated severe artefacts which precluded diagnostic coronary assessment of RCA, LCX and the distal segment of the LAD, dependent on the PHV position. This finding is supported by previous studies that described that these PHV types as being associated with valve-related artefacts that also prohibit the evaluation of the PHV itself on MDCT [8, 9, 11, 12]. The severe artefacts of the Björk–Shiley, Sorin tilting disc and Duromedics bileaflet PHVs were caused by the cobalt-chrome alloy that is present in these valves. Therefore, MDCT is not suitable for the assessment of the coronary arteries in patients who have one of these PHVs implanted. The Saint Jude PHV, consisting of a nickel alloy, produced fewer artefacts but still enough to preclude assessment of a limited number of coronary artery segments in the right coronary artery and circumflex terri- tory (segments 1, 13 and 14). The other segments did not suffer from artefacts that precluded assessment. The Saint Jude PHV is one of the most commonly implanted PHV types worldwide and therefore one of the most likely PHVs to be encountered. The possibility of the non-diagnostic image quality of the above-mentioned segments should be kept in mind when performing cardiac CT in these patients. In general, Carbomedics, ON-X and Medtronic Hall me- chanical PHVs caused no PHV-related artefacts hampering Table 4 Metallic properties of different prosthetic heart valves (PHV) PHV manufacturer PHV design Metallic contents* Mechanical bileaflet Titanium alloy Mechanical bileaflet Nickel alloy Mechanical bileaflet Titanium alloy Mechanical bileaflet Titanium alloy Mechanical bileaflet Cobalt-chrome alloy Mechanical tilting disc Titanium alloy Mechanical tilting disc Cobalt-chrome alloy Mechanical tilting disc Cobalt-chrome alloy Annuloplasty ring Elgiloy Biological Elgiloy Biological - Biological Haynes® alloy (stent post markers) - Stainless steel wire in sewing cuff Carbomedics St Jude ON-X Sorin bileaflet Duromedics Medtronic Hall Sorin monoleaflet Björk–Shiley CE CE Perimount Sorin Mitroflow Medtronic Mosaic Medtronic Freestyle Biological St Jude Epic Stented Biological *Manufacturer data