Towards Imaging the Beating Heart Usefully with a Conventional CT Scanner

Using a stroboscopic procedure based on electrocardiographic gating, "stationary" images of the beating heart can be obtained from X-ray computed tomography body scanners. However, due to the limited amount of time over which the heart motion is periodic, only a small number of projections (X-ray views) per phase of the heart cycle can be measured. It is suggested here how to obtain satisfactory image quality when only a limited number of projections per phase are available. The procedure involves recognizing that the material surrounding the heart is stationary, and so can be estimated using a large number of projections. It is shown how this estimate can be used to alter the measured projections in such a way that the image of the heart region can be significantly improved.