American Society of Radiologic Technologist (ASRT) Practice Exam

The detector that consists of a thin-film transistor array is known as what?

1. Flat-panel

2. Photostimulable phosphor plate (PSP)

3. Charge coupled device (CCD)

4. Complementary metal-oxide semiconductor (CMOS)

The correct answer is: Flat-panel

The correct answer is the flat-panel detector. Flat-panel detectors primarily utilize a thin-film transistor (TFT) array to convert incoming X-ray photons into electrical signals. This technology allows for efficient image capture in digital radiography. The TFT array consists of thousands of tiny individual sensors arranged in a grid, where each pixel corresponds to a specific part of the image, facilitating high-resolution images and rapid processing. In contrast, the other options represent different technologies used in radiographic imaging. The photostimulable phosphor plate is a component of computed radiography systems, which relies on photostimulable materials to capture and store X-ray images. Charge coupled devices are solid-state devices that are often used in video cameras and some imaging applications but do not specifically employ a TFT array structure. Lastly, complementary metal-oxide semiconductor (CMOS) technology is characterized by low power consumption and high-speed performance, yet it is also distinct from the flat-panel TFT mechanism utilized in digital radiography.