Question:  1

> If a person gets irradiated with 10 rads of x-rays to the liver- what is the equivalent dose to the liver? (make sure the units are correct)

Wr=1 for x-rays

 10 rads to the liver * Wr = 10Rems

Question:  2

> If a person gets irradiated with 10 rads of alpha particles to the liver - what is the equivalent dose?

Wr=20 for alphas

10 Rads to the liver * 20 = 200 rems

Question:  3

> If the tube emits 10mR/mAs at 100kVp at 40", what will the entrance skin exposure for a 100kVp, 20mAs shot? Assume the patient's skin is at 60" from the tube.

At 40”, the output for a 20mAs shot will be 10mR/mAs * 20mAs = 200mR at 40”

At 60” (the patient entrance) 200mR * 40^2 / 60^2 = 88.88mR

Question:  4

> If our entrance skin exposure is 50mR, what is the dose to the lungs and bone marrow given the following table?

For 1R entrance exposure, the lungs get 150mRad and Bone Marrow = 20mRad

50mR * 150mRad/1000mR = 7.5 mRad (lungs)

50mR * 20mRad/1000mR = 1 mRad (bone marrow)

Question:  5

> We have taken a chest xray and found the heart received 4mRad, thyroid - 3mRad, lungs - 5mRad and bone marrow - 1mRad. What is the effective dose equivalent? (ie:total body dose equivalent?)

Wt for heart = 0.05, lungs = 0.12, thyroid = 0.12, bone marrow= 0.12

4mRad*0.05 + 3mRad*0.12 + 5mRad*0.12 + 1mrad*0.12

.2 + .36 + .6 + .12 = 1.28 mRem (whole body dose equivalent)