Final answer:
The image receptor must intercept the full useful beam to energize a mobile fluoroscopic unit. It forms the image and ensures no unnecessary radiation exposure occurs. The correct answer is D.
Step-by-step explanation:
In mobile fluoroscopic equipment, the device that must intercept the entire useful beam in order to energize the mobile fluoroscopic unit is the image receptor. The image receptor, which includes devices such as fluoroscopic screens or cameras, captures the transmitted radiation to form an image. This is crucial for patient safety as it ensures that there is no unnecessary exposure to ionizing radiation if the image receptor is not in place. Other components like the collimating cone, spacer, and diaphragm help to shape and direct the beam but do not control the unit's energization.
Modern imaging techniques have evolved to use complex systems like SPECT (single-photon-emission computed tomography) and CT scans (computed tomography scans), which provide more detailed three-dimensional images. Technologies like Geiger counters, scintillators, and dosimeters measure radiation and are essential tools in ensuring safe practices in radiology and nuclear medicine.