| 摘要 |
<p>A method for velocity adaptive filtering of angiography image sequences is presented, where non-uniform locally varying motion may be present and in which an X-ray contrast medium is inserted intravascularly. A sequence of images are recorded before and/or during one or several contrast injection periods. The motion present in the image sequence contains a combination of two essentially different components: 1) the motion of contrast medium relative to the blood vessel; 2) the motion of the blood vessels relative to the fixed coordinate system given by the camera axis, induced by motion of the patients body or the patients internal organs. For medical diagnosis the previous of these is of primary interest and to obtain maximal clarity of this signal the latter should be maximally suppressed. The method is best described in that the recorded image sequence is analyzed locally within a spatio-temporal neighbourhood limited to a small window in spatial position as well as time. The vessel motion and the motion induced by contrast injection can be separately locally characterized by direction, velocity and spatio-temporal frequency.</p> |
