Final answer:
In an indirect-capture FPIR fluoroscopy system, the scintillator captures the light produced by x-rays and a photodiode converts this into an electrical signal, which is processed by a TFT array and a computer to construct the final image. Therefore, the correct answer is 3. scintillator.
Step-by-step explanation:
In an indirect-capture flat panel image receptor (FPIR) fluoroscopy system, the light produced by incident x-ray is captured primarily by the scintillator.
The scintillator converts the incoming x-ray photons into visible light. This light is then converted into an electrical signal by the photodiode, and not by the thin film transistor (TFT) array directly.
Finally, the electrical signal is processed by the TFT array to produce the image data, which is then sent to a computer to construct and display the final image.
A fluoroscopy system is a medical imaging technology that uses X-rays to obtain real-time moving images of the internal structures of a patient's body.
It's commonly used in various medical procedures to visualize and monitor different parts of the body in motion, such as the digestive system, blood vessels, and joints.