Angiography is the use of fluoroscopy to view the cardiovascular system. It is performed under ultrasound guidance, CT fluoroscopy or under image intensifier. This is frequently needed during fluoroscopy or endoscopy. This may be done using a portable ultrasound scanner, or with fluoroscopy (moving X-ray pictures). The exam ends when the person voids while the radiologist is watching under fluoroscopy. An upper GI series uses a barium contrast, fluoroscopy, and an X-ray. The use of CBCT before fluoroscopy potentially reduces patient radiation exposure. These machines use lower doses of radiation than medical fluoroscopy. Among the latter are frame rate settings, pulsed fluoroscopy and collimation. CT and fluoroscopy entail higher doses of radiation than do plain X-rays. Exposure to the patient can be reduced by minimizing fluoroscopy time. The placement of hardware can be guided by fluoroscopy, navigation systems, or robotics. Real-time fluoroscopy is used to assess bowel motility. Digital devices known as array detectors are becoming more common in fluoroscopy. These images can then be overlaid on live fluoroscopy.