Herment A, Guglielmi J P, Dumee P, Peronneau P, Delouche P
Inserm U. 256, Hôpital Broussais, Paris, France.
Ultrasonics. 1987 Sep;25(5):267-73. doi: 10.1016/0041-624x(87)90048-5.
The definition of medical ultrasound images is strongly limited by the need for low examination frequencies which is imposed by the high attenuation of acoustic waves in tissues. The filtering effect of imaging systems is described and quantified for echography, transmission tomography and reflection tomography. Improvement of image definition is demonstrated to be the result of a numerical restoration of the received echoes implemented, in the present case, by a simplified Kalman filter. The improvement in definition obtained is emphasized on simulated data and tissue images. The comparison between the results obtained from the three techniques shows that: if only echography provides a real-time acquisition of signals, tomographic methods lead to faster processing associated with a better signal-to-noise ratio on the reconstructed images, and reflection tomography offers the best definition.
医学超声图像的清晰度受到极大限制，这是因为组织中声波的高衰减要求采用低检查频率。本文描述并量化了成像系统对回波描记术、透射断层扫描和反射断层扫描的滤波效果。结果表明，图像清晰度的提高是通过在当前情况下由简化卡尔曼滤波器实现的对接收回波的数字恢复。在模拟数据和组织图像上强调了所获得的清晰度改善。三种技术所得结果的比较表明：只有回波描记术能实时采集信号，断层扫描方法能实现更快的处理，且重建图像的信噪比更高，而反射断层扫描提供了最佳的清晰度。
