MDCB EXAM QUESTIONS AND ANSWERS. A+ GRADED
GUIDE.
Which of the following CT numbers (Hounsfield units) is most closely related to lung tissue?
1. -1000
2. -750
3. 0
4. +1000
2. -750
Which of the following CT numbers (Hounsfield units) is most closely related to air?
1. -1000
2. -750
3. 0
4. +1000
1. -1000
Parent and daughter radioactive isotopes are said to be in secular equilibrium when they?
1. are equal in atomic weight
2. have the same half-life
3. have a constant ratio of activity
4. emit equivalent gamma energies
3. have a constant ratio of activity
The principle advantage of isocentric techniques over SSD techniques is?
1. the patient is not moved between fields
2. treatment can be given at a higher dose rate
3. it is not necessary to make immobilization devices
4. published tissue phantom ratios can be used
1. the patient is not moved between fields
When treating carcinoma of the bladder, the superior border of the radiation field is limited to the
superior aspect of S-1. This is to reduce toxicity to the?
1. pelvic crest
2. small bowel
3. kidney
4. ureters
2. small bowel
, For an individual member of the public, the equivalent dose limit to the lens of the eye is?
1. 50mSv/yr
2. 17mSv/yr
3. 5mSv/yr
4. 1.7mSv/yr
1. 50mSv/yr
The proper method for determining the location of the mechanical isocenter of a linear accelerator is
to?
1. rotate the gantry to horizontal and align the lasers
2. rotate the collimator and observe the crosshairs
3. move the table vertically and observe the image of the crosshairs
4. rotate the gantry about a pointer mounted independent of the gantry
4. rotate the gantry about a pointer mounted independent of the gantry
According to AAPM TG142, when linear accelerator quality assurance procedures are performed,
which of the following is the acceptable tolerance for the optical distance indicator (ODI)?
1. 1.0mm
2. 2.0mm
3. 3.0mm
4. 4.0mm
2. 2.0mm
According to AAPM TG142, when linear accelerator quality assurance procedures are performed,
which of the following is the acceptable tolerance for electron flatness?
1. 1%
2. 2%
3. 3%
4. 4%
3. 3%
Autoradiography of an encapsulated brachytherapy source is?
1. procedure using 3 radiographs to automatically identify radioactive seeds
2. manufacturing process used to ensure all sources have similar activity
3. method of using sources in the patient to produce radiographs
4. test for gross nonuniformity of the source within a source capsule
4. test for gross nonuniformity of the source within a source capsule
GUIDE.
Which of the following CT numbers (Hounsfield units) is most closely related to lung tissue?
1. -1000
2. -750
3. 0
4. +1000
2. -750
Which of the following CT numbers (Hounsfield units) is most closely related to air?
1. -1000
2. -750
3. 0
4. +1000
1. -1000
Parent and daughter radioactive isotopes are said to be in secular equilibrium when they?
1. are equal in atomic weight
2. have the same half-life
3. have a constant ratio of activity
4. emit equivalent gamma energies
3. have a constant ratio of activity
The principle advantage of isocentric techniques over SSD techniques is?
1. the patient is not moved between fields
2. treatment can be given at a higher dose rate
3. it is not necessary to make immobilization devices
4. published tissue phantom ratios can be used
1. the patient is not moved between fields
When treating carcinoma of the bladder, the superior border of the radiation field is limited to the
superior aspect of S-1. This is to reduce toxicity to the?
1. pelvic crest
2. small bowel
3. kidney
4. ureters
2. small bowel
, For an individual member of the public, the equivalent dose limit to the lens of the eye is?
1. 50mSv/yr
2. 17mSv/yr
3. 5mSv/yr
4. 1.7mSv/yr
1. 50mSv/yr
The proper method for determining the location of the mechanical isocenter of a linear accelerator is
to?
1. rotate the gantry to horizontal and align the lasers
2. rotate the collimator and observe the crosshairs
3. move the table vertically and observe the image of the crosshairs
4. rotate the gantry about a pointer mounted independent of the gantry
4. rotate the gantry about a pointer mounted independent of the gantry
According to AAPM TG142, when linear accelerator quality assurance procedures are performed,
which of the following is the acceptable tolerance for the optical distance indicator (ODI)?
1. 1.0mm
2. 2.0mm
3. 3.0mm
4. 4.0mm
2. 2.0mm
According to AAPM TG142, when linear accelerator quality assurance procedures are performed,
which of the following is the acceptable tolerance for electron flatness?
1. 1%
2. 2%
3. 3%
4. 4%
3. 3%
Autoradiography of an encapsulated brachytherapy source is?
1. procedure using 3 radiographs to automatically identify radioactive seeds
2. manufacturing process used to ensure all sources have similar activity
3. method of using sources in the patient to produce radiographs
4. test for gross nonuniformity of the source within a source capsule
4. test for gross nonuniformity of the source within a source capsule
