Final answer:
To reduce exposure time in radiography, higher milliamperage and kilovoltage, along with faster film-screen combinations, are employed. These practices improve the efficiency of radiation use, reducing the time needed to obtain a quality image and limiting radiation exposure. Shielding, distance, and the use of short-lived isotopes are additional measures to protect against radiation.
Step-by-step explanation:
Practices that enable the radiographer to reduce the exposure time required for a particular image include the use of a higher milliamperage, use of a higher kilovoltage, and use of a faster film-screen combination. These methods help by increasing the amount of radiation per unit time (milliamperage), allowing the radiation to penetrate more effectively (kilovoltage), and reducing the exposure time needed for the film to capture the image due to its increased sensitivity (fast film-screen combinations). Other radiation protection measures include keeping minimal time in the radiation environment, maintaining as much distance from the radiation source as possible, and employing shielding such as lead aprons and walls.
In terms of medical imaging, for instance, doses have decreased due to the usage of faster films which require less exposure time to produce an image. This reduction is not only beneficial for the patient but also for the technician who uses additional shielding and maintains a greater distance from the x-ray source to minimize occupational exposure.
Moreover, using isotopes with short half-lives in medical imaging can also limit the radiation dose, as they decay more quickly, reducing the time during which radiation is emitted.