In radiology, how is dose related to exposure time, and which practical step reduces exposure time?

• A. Dose is inversely proportional to exposure time; increase time to improve image quality.
• B. Dose is proportional to exposure time; reduce time by using automation, remote handling, prompt imaging, and efficient workflow.
• C. Dose is independent of exposure time; time-saving has no effect.
• D. Dose is proportional to square of exposure time; double time quadruples dose.

Answer: (B)

Dose to the patient scales with how long they are exposed to radiation, through the exposure time part of the mAs (mA × time). With the technique kept constant, dose changes linearly with time: double the exposure time and you double the dose; halve the time and you halve the dose. So reducing exposure time directly lowers the dose in a proportional way, while still aiming for the needed image quality.

A practical way to achieve this is by using automation, remote handling, prompt imaging, and an efficient workflow. Automation helps optimize exposure parameters quickly and consistently; remote handling lets the radiographer set up and trigger images without staying in the room, reducing delays; prompt imaging and streamlined workflows speed up the entire process, shortening the actual time the patient sits in the beam. Together, these steps minimize exposure time and thus lessen the patient dose while maintaining diagnostic quality.