Which of the following is NOT a type of image receptor?

The correct answer indicates that gas detectors are not classified as an image receptor in the context of radiological imaging. Image receptors are devices or materials that capture and convert various forms of radiation into visible images, which are critical for diagnostic imaging.

Film is a well-known traditional image receptor used in X-ray imaging that captures latent images until it is developed. Sensors and phosphor plates are also common image receptors, particularly in digital radiography and computed radiography, as they directly record and process X-ray images.

Gas detectors, while essential to radiation safety and monitoring, do not fulfill the role of capturing images for diagnostic purposes. Instead, they are utilized to measure and indicate the presence or levels of ionizing radiation in the environment, thereby serving a different function related to safety rather than imaging.