Gatenby J C, Hoddinott J C, Leeman S
Department of Medical Engineering and Physics, King's College School of Medicine and Dentistry, Dulwich Hospital, London, UK.
Phys Med Biol. 1989 Nov;34(11):1683-9. doi: 10.1088/0031-9155/34/11/015.
It is demonstrated that the instantaneous frequency of a backscattered echo sequence can be used to pinpoint the location of destructive interference effects. These interference artefacts, which are generally interpreted as speckle in the image, are generally removed by stochastic averaging or filtering methods applied to the acquired image. The method proposed here can detect such artefacts within individual A-lines, and thus differs from conventional techniques. Where speckle is recognised within each A-line, the artefact can be corrected on a local basis by the application of the frequency diversity technique. Because it relies only on A-line processing, the approach points the way towards a speckle reduction technique which can realistically be implemented on a real-time basis. In this paper, the principles of the technique are illustrated using a simple two-reflector model.
结果表明，背向散射回波序列的瞬时频率可用于精确确定相消干涉效应的位置。这些干涉伪像通常被解释为图像中的散斑，一般通过对采集图像应用随机平均或滤波方法来去除。这里提出的方法可以在单个A线内检测到此类伪像，因此与传统技术不同。在每条A线内识别出散斑的地方，可以通过应用频率分集技术在局部基础上对伪像进行校正。由于该方法仅依赖于A线处理，因此为一种可实际实时实现的散斑减少技术指明了方向。在本文中，使用一个简单的双反射器模型来说明该技术的原理。
