Phantom measurements and error estimation in volume determination with ECG-triggered cardio-computed tomography.
The ECG-triggered CT-imaging-procedure (computed tomography system SOMATOM with ECG unit) provides the possibility of displaying the beating heart in each of its individual mobility phases. Thus the telediastolic and telesystolic volumes of the left ventricle can be determined approximately, and from this its ejection fraction. The present paper describes measurements on moving phantoms (acryl plate, fluid-filled balloon). They give an estimation of the accuracy with which cross-sectional areas can be determined by the above-mentioned CT-system as a function of the frequency of the movement and of the number of tube rotations per slice. Basing on those models and not paying regard to further sources of error as for example an irregular heartbeat, it is found that the ejection fraction can be determined with a relative error of +/- 11% . . . +/- 13% depending on the beat frequency.
D002302:Cardiac Output; D004562:Electrocardiography; D006321:Heart / Q000000981:diagnostic imaging*; D006801:Humans; D008953:Models, Anatomic; D013318:Stroke Volume; D014057:Tomography, X-Ray Computed / Q000295:instrumentation*