acoustic shadow field的用法和样例：
- Most of the branchial cysts, neurinomas, lymphoma had lateral acoustic shadow.
- Sonography showed curvilinear hyperechogenicity with an acoustic shadow.
- Results Ossificans myositis had specific features on sonograms.Mass had low level echo early phase and strong echo later stage with acoustic shadow.
- In the ultrasonogram, we found that the metal and glass foreign bodies were followed by acoustic tails, and the rest of non-metal were followed by acoustic shadow.
- Results A hyperechoic area with acoustic shadow below appeared immediately after alcohol injection.The hyperechoic area diffused and its boundary was illegible following injection.