One of the most efficient ways to ensure that a patient is receiving an acceptable radiation dose is to optimize a scanning protocol to each patient.
Adjustments to technical parameters and scanning range of a protocol are made based upon the patient’s size, age, and clinical areas of interest.
mA has a proportional relationship to radiation dose. If mA is halved, the radiation dose is halved.
kV has a direct effect on patient dose. As the kV is increased, the patient’s radiation dose is also increased.
mA and kV should be kept to the lowest possible levels to acquire optimal images to keep the patient’s radiation dose to a minimum.
The collimation that is utilized during a CT exam can have an indirect impact on the dose a patient receives.
The collimation of the x-ray beam impacts the dose profile of a patient.
The dose profile is the area of the patient that is exposed to radiation.
Wide collimation means that the patient’s dose will be increased in the z-axis (thick slices) and narrow collimation means the patient dose will be decreased in the z-axis (thin slices).
However, thin slices can produce images with increased noise which may require an increase in mA.