当然，超声波很早就已用于医疗成像，其应用的依据是声波在密度更大的组织中传播速度更快。

Ultrasound has, of course, long been used in medical imaging. It relies on the fact that sound travels faster through denser tissues.

youdao

当然，超声波很早就已用于医疗成像，其应用的依据是声波在密度更大的组织中传播速度更快。

Ultrasound has, of course, long been used in medical imaging. It relies on the fact that sound travels faster through denser tissues.

youdao