Time
Decreasing the amount of time you are exposed to medical radiation will automatically decrease your dose, if all other factors are the same. This means thorough pre-procedure planning to increase efficiency and streamline the workflow during the procedure, intimate knowledge of the devices and/or radioactive materials used during the exam, and a healthy respect for the power of radiation beams that you can't see.   

Distance
When you increase your distance from the radiation source, your amount of radiation exposure is reduced by a square of the distance. For instance, if you move 2 feet away, your exposure level decreases by a factor of 22, or 4. While there are practical limits to how much distance you can put between yourself and the radiation source, even a small increase can be beneficial. The Inverse Square Principle makes distance one of the best safeguards in reducing dose. Even one step back from the imaging field can have a profound effect on reducing exposure from scatter.

Shielding
The appropriate material for adequate shielding from radiation depends on the type of radiation being used. For many medical imaging procedures, such as X-rays and CT scans, lead shielding is used. This can be lead aprons worn by radiological technologists and radiologists, or lead aprons draped from the procedure table to act as a barrier between the radiation source and the healthcare provider. Some people prefer not to use the recommended shielding protocols because shielding equipment can be inconvenient, bulky, uncomfortable, and time-consuming to put on and take off. For instance, lead aprons and thyroid shields can get heavy and cause strain when worn for long periods of time, and goggles can be difficult to get used to. However, these measures are critical for safe radiation use, and many are mandated by regulatory authorities. In addition, one should always wear a monitor badge and follow institutional guidelines for having it read. Never take shortcuts when it comes to radiation safety.

There are many steps a healthcare provider can take to decrease a patient's radiation exposure during the course of an imaging procedure. Some steps can be applied with general rules, while others are specific to the type of equipment used and the type of procedure being performed.   

The Use of Low-dose Imaging Equipment 
There have been many innovations in the past decade that give the user more control over radiation dose so that high-quality images can be obtained with lower radiation dose. These technical advances provide greater flexibility to adjust the dose based on the clinical needs of the individual patient. It is important that everyone using the imaging equipment has a thorough knowledge of its low-dose capabilities and has up-to-date training on its proper use.

ALARA principles outlined in Section 1 should always be followed. The amount of time the patient is exposed to radiation should be minimized as much as possible. The distance from patient to the radiation source should be optimized to balance the desire for high image quality with the need for responsible radiation use. And finally, if feasible with the procedure being performed, the patient should be provided with proper shielding.