Abstract 541: Prosthetic Valve Evaluation Using Prospective Triggering With 256-Detector Row Computed Tomography Reduces Radiation Dose
Purpose: Imaging of prosthetic heart valves (PHV) with computed tomography may provide detailed imaging of periprosthetic tissues at the expense of significant radiation exposure. A novel protocol using 256-detector row computed tomography (MDCT) may allow dose reduction.
Methods: Eleven patients with one or more PHV (10 mechanical and 4 biological prostheses; 10 aortic, 3 mitral, 1 tricuspid) underwent cardiac ECG-gated 256-detector row CT (Philips iCT), using either
a novel low dose scan protocol with a low-dose (120kV, 50 – 80mAs) unenhanced retrospective scan followed by a prospectively triggered scan (120kV, 200 –250 mAs) at maximum valve opening and closure or
a standard retrospectively gated scan (120 KV 600 –700mAs). Systematic PHV analysis of the prosthesis and periprosthetic tissue was done using both static and dynamic images.
Results: Six patients were scanned using the novel scan protocol. The standard protocol was used in 5 because of arrhythmia, a relatively radiolucent biological valve or multiple valves. Resultant mean dose was 3.48 and 7.27 mSv, respectively. All 14 valve prostheses were successfully visualized with limited artefacts. Prospective triggering missed full opening in one biological valve. MDCT findings included: normal valve morphology (n = 3), subvalvular calcification (n = 3), narrowed left ventricular outflow tract (n = 1), leaflet restriction (n = 1), thickening of biological leaflets (n = 2) and subvalvular pannus tissue (n = 4).
Conclusion: Prosthetic heart valve evaluation using MDCT with prospective triggering achieves dose reduction and provides detailed anatomical information.