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Name the parts of the "scotty dog" seen in a correctly positioned oblique lumbar spine?
- The scotty's
- Ear- the superior articular process
- Nose- the transverse process,
- Eye - the pedicle,
- Neck- the pars interarticularis,
- Body - the lamina
- Front foot- the inferior articular process.
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Name the three things that have an effect on patient dose.
Inherent filtration, added filtration and SID.
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The housing surrounding an x-ray tube functions to
The housing surrounding an x-ray tube functions to
- Protect one from electric shock and
- keep leakage radiation to a minimum.
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Acording to the NCRP, the annual occupational dose equivalent limit to the lens of the eye is
- The Eyes is 150 mSv
- the annual occupational whole-body dose equivalent limit is
- 50 mSv (5 rem or 5000 mrem).
- students under 18 years is
- 1 mSv (100 mrem or 0.1 rem).
- lens of the eye
- 150 mSv (15 rem or 15,000 mrem).
- the skin and extremities is
- 500 mSv (50 rem or 50,000 mrem).
- The total gestational dose equivalent limit for embryo/fetus of a pregnant radiographer is
- 5 mSv (0.5 rem or 500 mrem).
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Which two things will reduce patient dose during fluoroscopy?
Using 2.5 mm Al filtration and Restricting tabletop intensity to less than 10 R/min
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Stochastic effects of radiation include
- Genetic Alterations
- Stochastic effects of radiation are nonthreshold and randomly occurring.
Examples of stochastic effects include carcinogenesis and genetic effects.
Stochastic effects is directly related to the radiation dose; that is, as radiation dose increases, there is a greater likelihood of genetic alterations or development of cancer.
- Nonstochastic effects are predictable, threshold responses; that is,
- a certain quantity of radiation must be received before the effect will occur, and the greater the dose, the more severe the effect.
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Which of the following is the approximate skin dose for 5 minutes of fluoroscopy performed at 1.5 mA?
the approximate skin dose for 5 minutes of fluoroscopy performed at 1.5 mA?
15 rad
- EXPLANATION: Fluoroscopic skin dose is greater than radiographic skin dose because the x-ray source is much closer to the patient.
- The generally accepted rule is that the skin receives 2 rad/min/mA. Therefore, 2 rad/min for 5 min equals 10 rad/mA. At 1.5 mA, the patient dose is 15 rad (2 rad/5 min/1.5 mA).
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Which cells is the least radiosensitive?
EXPLANATION: Bergonié and Tribondeau theorized in 1906 that all precursor cells are particularly radiosensitive (e.g., stem cells found in bone marrow).
- There are several types of stem cells in bone marrow, and the different types differ in degree of radiosensitivitity Of these, red blood cell precursors, or erythroblasts, are the most radiosensitive. White blood cell precursors, or myelocytes, follow in 2nd place.
- Platelet precursor cells, or megakaryocytes, are even less radiosensitive.
Myocytes are mature muscle cells and are fairly radioresistant.
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What is the approximate ESE for the average following exams
AP cervical spine-
AP supine L-Spine-
AP supine abdomen -.
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What is the approximate ESE for the following EXAMS:
- AP cervical spine- 80 mrad (0.080 rad). AP supine L-Spine- 350 mrad (0.35rad).
- AP supine abdomen -300 mrad.
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G
Which of the following are considered most radiosensitive?
A.
Lymphocytes
B.
Ova
C.
Neurons
D.
Myocytes
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Correct. The answer is A.
EXPLANATION: Mature white blood cells (lymphocytes) are considered the most radiosensitive cells. Ova (female germ cells) are very radiosensitive, but not to the same degree as lymphocytes. Myocytes (muscle cells) and especially neurons (nerve cells) are actually radioresistant. (Gurley and Callaway, 6th ed., p. 254)
A
Which of the following are considered most radiosensitive?
- Lymphocytes
- Ova
- Neurons
- Myocytes
- Answer is A.
- EXPLANATION:
- Mature white blood cells (lymphocytes) are considered the most radiosensitive cells.
Ova (female germ cells) are very radiosensitive, but not to the same degree as lymphocytes.
Myocytes (muscle cells) and especially neurons (nerve cells) are actually radioresistant.
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The purpose of filters in a film badge is
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The purpose of filters in a film badge is to measure radiation quality.
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How are LET and biologic response related?
LET and biologic response are directly related.
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Name the two advantages of beam restriction
The advantages of beam restriction are
1. less scattered radiation is produced.
2. less biologic material is irradiated.
EXPLANATION: With greater beam restriction, less biologic material is irradiated, thereby reducing the possibility of harmful effects. If less tissue is irradiated, less scattered radiation is produced, resulting in improved IR contrast.
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The rad is the unit of what?
The r ad is the unit of radiation dose.
- Note:
- Rad (radiaton absorbed doseati) expresses energy deposited (as a result of ionizations) in any kind of absorber.
The unit of exposure, the roentgen, is quantity of ionization in air.
The unit of dose equivalent is the rem ( radiation equivalent man), which expresses dose to biologic material.
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What are the late effects of radiation
The late effects of radiation are considered to
1. have no threshold dose.
2. are directly related to dose
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The biologic effect on an individual is dependent on which 3 Things?
j
The biologic effect on an individual is dependent on the following 3 Things.
- 1. Type of tissue interaction(s)
- 2. Amount of interactions
- 3. Biologic differences
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How do fractionation and protraction affect radiation dose-effects?
1.
They reduce the effect of radiation exposure.
2.
They permit cellular repair.
3.
They allow tissue recovery
Fractionation and protraction affect radiation dose-effects in three ways
1. They reduce the effect of radiation exposure.
2. They permit cellular repair.
3. They allow tissue recovery
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Filtration is added to the x-ray beam to
Filtration is added to the x-ray beam to
produce an x-ray beam with higher average energy
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Which two things (are) associated with Compton scattering?
Which two things (are) associated with Compton scattering?
1. High-energy incident photons
2. Outer-shell electrons
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Which contributes most to patient dose?
A.
The photoelectric effect
The Photo/Electrict effect contributes most to patient dose?
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Substituting intensifying screens having a speed of 200 in place of a 100-speed system will
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Substituting intensifying screens having a speed of 200 in place of a 100-speed system will require one half of the exposure of 100-speed screens and enable the radiographer to decrease the exposure time.
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What is the term used to describe x-ray photon interaction with matter and the transference of part of the photon's energy to matter?
The term used to describe x-ray photon interaction with matter and the transference of part of the photon's energy to matter is called Scattering
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3 Factors that determine the amount of scattered radiation produced include
- 3 Factors that determine the amount of scattered radiation produced include
- 1. radiation quality.
- 2. field size.
- 3. pathology.
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Which type of dose–response relationship expresses radiation-induced leukemia?
-
Linear,Non-Threshold type of dose–response relationship
- expresses radiation-induced leukemia?
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