focal zone meaning in English

病灶区
聚焦带
聚焦区
震源区

It combines the advantages of ultrasound and optical technology . ultrasonic wave scatters much less in biological tissue than light wave and can be used as a localizer in tissue . the diffused photons tagged by the ultrasound in the focal zone will be collected and used for image
超声调制主要是使散射介质内的散射粒子的分布以及光学特性发生变化，比如说使介质的折射率发生改变而导致光学相位变化，结合散射和自相关理论可以解释一些超声调制多重散射光的现象。