These tests use extremely short bursts of x-ray beams and pose little risk. Other x-ray tests include fluoroscopy, and CT scans. Fluoroscopy produces a moving x-ray image of internal organs. A constant stream of x-rays passes through the person. This casts shadows of internal structures onto a fluorescent screen.
Fluoroscopy reveals less detail than a standard still x-ray.
It also exposes the person to somewhat more radiation. For these reasons, radiologists use fluoroscopy only when they need to see movement of internal structures. A CT scan produces an image of a cross-section of the body. CT is short for computerized tomography. It sends many beams though the same area.