CT FINAL EXAM
CT technologists must understand both the ___________ & ___________ of examinations and
take steps to maximize the ________ & minimize the ____________. - ANSWER
risks & benefits
positive, negative
What are the two components regarding radiation dose to the patient? - ANSWER
1) appropriate patient selection
2)minumizing the dose to the pt w/ out compromising the diagnostic image quality
CT scans provide one of the ____________ radiation doses in diagnostic radiology. *** (slide 3)
- ANSWER higher
--large # w/ very thin slices
X-rays damage cells in _______ ways.....how? - ANSWER 2; 1) Direct
interaction between an x-ray photon and DNA bonds with the nucleus of the cell within the
patient. 2) X-ray photon indirectly produces ion pairs in tissues as it passes through the body
,X-rays damage cells in two ways: - ANSWER -Direct interaction with DNA
bonds.
-Indirect effect caused by ionization of chemicals in the body.
Direct Interaction is also known as.... - ANSWER Target Theory
Gestating babies are ________ radiosensitive. - ANSWER most
Radiation effects may be __________ but are more likely to be seen___________________ . -
ANSWER -immediate
-over a long period of time
What are the effects of x-ray radiation?(4) - ANSWER -cancer
-genetic effects of future generations
-Long term effects (10-20 yrs)
-effects of the embryo & fetus
--first trimester=maximum radiosensitivity
,The unit of x-ray exposure in air - ANSWER Roentgen (R)
Units of absorbed dose - ANSWER radiation absorbed dose=rad
SI unit=Gray(Gy)
100 rad=1 Gy
1 rad= .01 Gy or 1 cGy
Convert the following:
50 rad =
200 Gy =
.1 rad = - ANSWER .5 Gy
20,000 rad
.001 Gy or 1mGy
Determine the total dose in Gy if an exam acquires
300 slices producing 2 rads per slice. - ANSWER 300 slices x 2 rad/slice = 600
rad x .01 = 6 Gy
, Accounts for different types of ionizing radiation - ANSWER Quality factor (Q)
In CT, the quality factor is ? - ANSWER 1
Attempts to account for the effects particular to the patient's tissue that has absorbed the
radiation dose - ANSWER Effective dose
Effective dose attempts to quantify dose based upon the_________________ of certain tissues
or organs. - ANSWER radiosensitivity
The uniformity of the dose __________ as the SFOV and patient thickness ___________. -
ANSWER decreases
increase
organ doses are higher for children (or small adults) compared with (larger) adults - ANSWER
........
CT technologists must understand both the ___________ & ___________ of examinations and
take steps to maximize the ________ & minimize the ____________. - ANSWER
risks & benefits
positive, negative
What are the two components regarding radiation dose to the patient? - ANSWER
1) appropriate patient selection
2)minumizing the dose to the pt w/ out compromising the diagnostic image quality
CT scans provide one of the ____________ radiation doses in diagnostic radiology. *** (slide 3)
- ANSWER higher
--large # w/ very thin slices
X-rays damage cells in _______ ways.....how? - ANSWER 2; 1) Direct
interaction between an x-ray photon and DNA bonds with the nucleus of the cell within the
patient. 2) X-ray photon indirectly produces ion pairs in tissues as it passes through the body
,X-rays damage cells in two ways: - ANSWER -Direct interaction with DNA
bonds.
-Indirect effect caused by ionization of chemicals in the body.
Direct Interaction is also known as.... - ANSWER Target Theory
Gestating babies are ________ radiosensitive. - ANSWER most
Radiation effects may be __________ but are more likely to be seen___________________ . -
ANSWER -immediate
-over a long period of time
What are the effects of x-ray radiation?(4) - ANSWER -cancer
-genetic effects of future generations
-Long term effects (10-20 yrs)
-effects of the embryo & fetus
--first trimester=maximum radiosensitivity
,The unit of x-ray exposure in air - ANSWER Roentgen (R)
Units of absorbed dose - ANSWER radiation absorbed dose=rad
SI unit=Gray(Gy)
100 rad=1 Gy
1 rad= .01 Gy or 1 cGy
Convert the following:
50 rad =
200 Gy =
.1 rad = - ANSWER .5 Gy
20,000 rad
.001 Gy or 1mGy
Determine the total dose in Gy if an exam acquires
300 slices producing 2 rads per slice. - ANSWER 300 slices x 2 rad/slice = 600
rad x .01 = 6 Gy
, Accounts for different types of ionizing radiation - ANSWER Quality factor (Q)
In CT, the quality factor is ? - ANSWER 1
Attempts to account for the effects particular to the patient's tissue that has absorbed the
radiation dose - ANSWER Effective dose
Effective dose attempts to quantify dose based upon the_________________ of certain tissues
or organs. - ANSWER radiosensitivity
The uniformity of the dose __________ as the SFOV and patient thickness ___________. -
ANSWER decreases
increase
organ doses are higher for children (or small adults) compared with (larger) adults - ANSWER
........
