If a patient dose is 0.5 mGy at a 50 inch SSD, what would it be at a 64 inch SSD?

To determine the patient dose at a different source-to-skin distance (SSD), one can use the inverse square law, which states that the intensity of radiation is inversely proportional to the square of the distance from the source. This means that when the distance increases, the dose received decreases.

In this context, we can start with the patient dose at a 50 inch SSD, which is 0.5 mGy. We wish to find out what the dose would be at a 64 inch SSD.

Using the inverse square law, we can set up the following relationship:

[

\frac{Dose_1}{Dose_2} = \left(\frac{Distance_2}{Distance_1}\right)^2

]

Plugging in the known values:

[

\frac{0.5 , mGy}{Dose_2} = \left(\frac{64 , inches}{50 , inches}\right)^2

]

Calculating the ratio of distances:

[

\left(\frac{64}{50}\right)^2 = \left(1.28\right)^2 = 1.6384

]

Now rearranging to solve for Dose_2:

[

Dose