RADIOLOGY CORE EXAM QUESTIONS AND
CORRECT DETAILED ANSWERS WELL VERIFIED
.GRADED A+
What is the Mean Glandular Dose limit for a breast phantom? -
ANSWER -3mGy (grid), 1mGy (no grid)
What is the minimum Spatial Resolution required for screen-film
mammography? - ANSWER -12 lp/mm
What is the interval for Accreditation and Certification for
mammography centers? - ANSWER -3 years
,How long must mammography centers keep patient records? -
ANSWER -5 years
What are the Mammogram Training Requirements? - ANSWER -240
exams in 6 months, 3 months of training, 60 hrs of mams education
What is the minimum energy for ionizing radiation? - ANSWER -15eV
What is the K shell binding energy of Tungsten? - ANSWER -69.5 KeV
How much mA and kVp are required to double Intensity of the X-ray
Spectrum? - ANSWER -15%kVp, double mA
What is the relationship between focal spot and anode angle to the
heel effect? - ANSWER -Small anode angle results in a small effective
focal spot but with an increased Heel Effect.
What is the relationship between mA and kVp to effective focal spot? -
ANSWER -Increased mA results in "blooming" of focal spot, but
increased kVp results in focal spot "thinning"
, What is the relationship between energy and atomic number (Z) to the
photoelectric effect? - ANSWER -Photoelectric effect dominates
Compton scatter at lower energies (20-30 KeV), and higher Z materials
are much more likely to have photoelectric effect (Z^2)3
What is the relationship between atomic number (Z) photoelectric
effect (PE) to image contrast? - ANSWER -High Z has more
photoelectric effect (PE) and therefore provides greater contrast
resolution, especially at an average energy close to its K-edge.
What is the relationship between max energy (kVp) and average energy
to maximize imaging of a contrast agent? - ANSWER -Ave energy is 1/2
to 1/3 of the max energy (kVp). In other words, you want the kVp set to
at least twice the binding energy of the contrast agent being used
(Iodine K edge 33 keV so use 66kVp, Barium is higher at 37keV so use
74kVp)
How would you change mA and kVp to better visualization low contrast
tissue? - ANSWER -Increase mA, keep kVp constant (or reduce it to
further improve contrast)
What is the relationship between energy (kVp) to linear attenuation
coefficient and half value layer? - ANSWER -Increased kVp results in a
decreased linear attenuation coefficient and an increase in the half
value layer needed to attenuate 50% of the x-ray beam
CORRECT DETAILED ANSWERS WELL VERIFIED
.GRADED A+
What is the Mean Glandular Dose limit for a breast phantom? -
ANSWER -3mGy (grid), 1mGy (no grid)
What is the minimum Spatial Resolution required for screen-film
mammography? - ANSWER -12 lp/mm
What is the interval for Accreditation and Certification for
mammography centers? - ANSWER -3 years
,How long must mammography centers keep patient records? -
ANSWER -5 years
What are the Mammogram Training Requirements? - ANSWER -240
exams in 6 months, 3 months of training, 60 hrs of mams education
What is the minimum energy for ionizing radiation? - ANSWER -15eV
What is the K shell binding energy of Tungsten? - ANSWER -69.5 KeV
How much mA and kVp are required to double Intensity of the X-ray
Spectrum? - ANSWER -15%kVp, double mA
What is the relationship between focal spot and anode angle to the
heel effect? - ANSWER -Small anode angle results in a small effective
focal spot but with an increased Heel Effect.
What is the relationship between mA and kVp to effective focal spot? -
ANSWER -Increased mA results in "blooming" of focal spot, but
increased kVp results in focal spot "thinning"
, What is the relationship between energy and atomic number (Z) to the
photoelectric effect? - ANSWER -Photoelectric effect dominates
Compton scatter at lower energies (20-30 KeV), and higher Z materials
are much more likely to have photoelectric effect (Z^2)3
What is the relationship between atomic number (Z) photoelectric
effect (PE) to image contrast? - ANSWER -High Z has more
photoelectric effect (PE) and therefore provides greater contrast
resolution, especially at an average energy close to its K-edge.
What is the relationship between max energy (kVp) and average energy
to maximize imaging of a contrast agent? - ANSWER -Ave energy is 1/2
to 1/3 of the max energy (kVp). In other words, you want the kVp set to
at least twice the binding energy of the contrast agent being used
(Iodine K edge 33 keV so use 66kVp, Barium is higher at 37keV so use
74kVp)
How would you change mA and kVp to better visualization low contrast
tissue? - ANSWER -Increase mA, keep kVp constant (or reduce it to
further improve contrast)
What is the relationship between energy (kVp) to linear attenuation
coefficient and half value layer? - ANSWER -Increased kVp results in a
decreased linear attenuation coefficient and an increase in the half
value layer needed to attenuate 50% of the x-ray beam
