Influence of motion on image quality with a 64-channel CT scanner

摘要

Physiological motions can affect Computed Tomography (CT) exam. While the impact of some motions on CT imaging can be reduced, other physiological motions are unavoidable. To attempt correcting the resulting images, it is necessary to understand how the artifacts are formed and their influence on the image quality. Using a cardiac phantom and a dynamic platform, we have studied the influence of a translation in the z-axis associated with a rotation in the z-axis (at different speeds) on the quality of axial images using a 64-channel scanner. The results show that, the deformation, the detectability and the contrast of the calcifications are of course dependent on the density and size of the calcification but also on the movement they undergo. The noise in CT imaging is also affected by motion. The influence of motion on the image quality depends on the examined object and unfortunately cannot be predicted. The corruption of the data results in the loss of information about the form, the contrast and/or the size of the scanned object. This corruption can lead to diagnosis errors by mimicking diseases or by masking physiologic details