Multidetector-Row Computed Tomography Imaging Characteristics of Mechanical Prosthetic Valves

Background and aim of the study: Electrocardiogram-gated multidetector-row computed tomography (MDCT) imaging may aid in the evaluation of prosthetic valve dysfunction. A pulsatile in vitro model was developed to study the MDCT imaging characteristics of mechanical heart valves (MHVs). Methods: Bjork-Shiley (BS), St. Jude Medical (SJM), Medtronic-Hall (MH), CarboMedics (CM) and ON-X valves were inserted into an in vitro pulsatile model and scanned using a 64-detector row scanner. The image quality regarding visualization of the leaflets, prosthetic detail and periprosthetic detail, as well as the presence of image artifacts, was scored on a four-point scale. Results: The image quality for the BS valve was scored poor to moderate for all criteria, and was inferior to that seen with the other valves. Leaflet visualization was excellent for all the other valves. The prosthetic detail was good for MH and SJM valves, and excellent for the CM and ON-X valves. Periprosthetic detail was good for MH, SJM and CM valves, and excellent for ON-X valves. Artifacts were moderate for MH and SJM valves, minor for CM, and minimal for ON-X. All differences were shown to be statistically significant (p <0.001). Conclusion: The pulsatile in vitro model is an effective tool to detect differences in the MDCT imaging characteristics of MHVs. The image quality is determined by the prosthesis components and, to a lesser degree, by prosthesis design. Modern carbon-titanium MHVs yield good to excellent image quality on MDCT.