What does the term "fluoroscopy" refer to?

Fluoroscopy refers to a medical imaging technique that provides real-time moving images of the interior of a patient's body. This is accomplished by utilizing X-rays to create a continuous stream of images, allowing clinicians to observe processes in motion, such as swallowing or the movement of organs. This dynamic capability is particularly useful in procedures that require guidance, such as catheter placements or the evaluation of the gastrointestinal tract.

Static imaging using X-rays, as described in the first option, produces still images and lacks the real-time observation feature inherent in fluoroscopy. The third option relates to magnetic resonance imaging (MRI), which operates on a different principle involving magnetic fields and radio waves, not X-rays. The fourth choice discusses photo imaging without radiation, which does not apply to fluoroscopy—since fluoroscopy specifically involves the use of X-ray radiation to create its images. Thus, the key aspect that defines fluoroscopy is its ability to provide continuous, real-time visualization of bodily functions using X-ray technology.