U-arm X-ray machine and sickle arm are actually a kind of X-ray machine, but some people are used to calling it U-arm X-ray machine, and some people are used to calling sickle-arm X-ray machine. In fact, these two types are fixed X-ray machines. This U-arm X-ray machine has a U-shaped arm, which can be rotated up and down by 90°. It can be used to shoot various postures, such as standing postures like chest radiographs, and prone postures of the lumbar spine. And there is no need to configure a chest radiograph stand separately, just need a medical radiographing bed when shooting prone position. Of course, you can also choose a flat-panel detector for the U-arm X-ray machine. The flat-panel detector is what we usually call the DR system.