Question 1
Question
Protons and neutrons in a nucleus are termed:
Answer
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Beta-particles
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Photons
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Nucleons
Question 2
Question
Linear attenuation coefficient of photoelectric absorption (photoelectric effect interaction probability) τ is:
Answer
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Inversely proportional to the atomic number of the element Ζ
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Inversely proportional to the mass number A
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Proportional on the density ρ
Question 3
Question
Linear attenuation coefficient of photoelectric absorption τ depends strongly (approximately to the 4-th power) on:
Question 4
Question
Linear attenuation coefficient for Compton effect (Compton scattering interaction probability) δ is proportional to:
Answer
-
Atomic mass number A
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Density of substance
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The ratio A/Z
Question 5
Question
Linear attenuation coefficient for Compton effect is proportional to:
Question 6
Question
Linear attenuation coefficient for pair production (electron-positron production probability) X is proportional to:
Question 7
Question
Predominant mode of interaction between conventional diagnostic x-ray and biological tissues (Figure 11. not included) is:
Question 8
Question
Interaction of photonic ionizing radiation with matter will
Answer
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Reduce radiation intensity
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Not change radiation intensity
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Increase radiation intensity
Question 9
Question
What type of interaction between diagnostic x-rays and matter is improbable:
Question 10
Question
Consider attenuation of photon beam in water/soft tissue (figure 11. not included). Which statement is true:
Answer
-
Photons may undergo two successive photoelectric transitions
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Compton scattering has a threshold energy of 1.022 MeV
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Photoelectric effect increases with photo energies
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Photoelectric and Compton effects equal at 25 KeV
Question 11
Question
Roentgen Rays are:
Answer
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Photons
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Electrons
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Positrons
Question 12
Question
Roentgen rays are:
Question 13
Question 14
Question
The wavelength of the roentgen radiation is within the range of:
Answer
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380 - 760 nm
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0.76 - 1000 µm
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10 - 380 µm
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Less than 10 nm
Question 15
Question 16
Question
Characteristic x-ray radiation:
Answer
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Has continuous energy spectrum
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Does not differ from braking radiation spectrum
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Is obtained from K and L shell electron transitions from high atomic shells.
Question 17
Question
Continuous x-ray energy spectrum:
Answer
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Contains several photons with different energy
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Does not differ from the characteristic x-ray spectrum
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Is a result of rapid deceleration of electrons near target nuclei
Question 18
Question
Intensity ψ of radiation in x-ray tube is proportional to:
Answer
-
The atomic number Z of anode's material
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The 3-th power of anode U3/a
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The 2-nd power of anode I2/a
Question 19
Question
Intensity ψ of roentgen radiation (x-ray tube) is proportional to:
Question 20
Question
Intensity ψ of roentgen radiation (x-ray tube) if proportional to:
Answer
-
Density p of the cathode material
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The 2-nd power of anode voltage U2/a
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The 2-nd power of anode current I2/a
Question 21
Question
Minimum wavelength λmin (maximum energy) of x-ray tube radiation depends on:
Question 22
Question
Filters in x-ray apparatus modify:
Answer
-
The minimum wavelength λmin of x-ray braking spectrum
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The amount of anode Voltage Ua
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The intensity ψ of roentgen radiation
Question 23
Question
Intensity ψ of the Roentgen rays is proportional to:
Question 24
Question
Hardness of x-ray radiation (harder/softer) is changed by:
Answer
-
Anode voltage Ua
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Beam intensity ψ
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Anode current Ia
Question 25
Question
The relationship between HVL (Half Value Layer) and linear attenuation coefficient µ is
Answer
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HVL = ln(2)/µ
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HVL = µ/ln(2)
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HVL = µ*ln(2)
Question 26
Question
Water is said to be soft tissue equivalent with respect to x-ray attenuation. This is because water and soft tissue have approximately the same properties. Which properties are NOT the same? (there are more than one correct answers)
Answer
-
Effective atomic number Zeff
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Effective molecular weight
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Physical density p
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Attenuation Coefficient µ
Question 27
Question
The purpose of the introduction of contrast substances in the roentgen diagnostics is to:
Answer
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Obtain coloring in the roentgenogram and not only black and white images
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Increasing the contrast between soft tissues
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Reduce the radiation dose on patients
Question 28
Question
Contrast substances in diagnostics radiology will:
Question 29
Question
Which of the listed chemical elements provides maximum contrast in diagnostic radiology:
Answer
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Calcium: Z = 20, p = 1.55 g/cm3
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Barium: Z = 56, p = 3.5 g/cm3
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Iodine: Z = 53, p = 4.94 g/cm3
Question 30
Question
Roentgen osteo-densitometry (measurement of bone density) is based on which of the following phenomena:
Answer
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Diffraction of roentgen rays (x-rays)
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Scattering of roentgen rays (x-rays)
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Attenuation of Roentgen rays (x-rays)
Question 31
Question
Hounsfield Unit (CT number) for bones is equal to:
Question 32
Question
Hounsfield unit (CT number) for air is equal to:
Question 33
Question
Hounsfield unit (CT number) for water is equal to:
Question 34
Question
Hounsfield unit (CT number) is defined as:
Answer
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(µ-tissue + µ-water) / µ-water
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(µ-tissue - µ-water) / µ-water
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(µ-tissue - µ-water) / µ-tissue
Question 35
Question
Predominant x-ray interaction mode in CT scanning is:
Answer
-
Photoelectric absorption & compton scattering
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Electron-positron pair production & photoelectric absorption
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Compton scattering & electron-positron pair production
Question 36
Question
CT diagnostic imaging is based on the phenomenon of:
Answer
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Reflection of reoentgean rays at the boundary between different structures
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Absorption of roentgen rays by tissues exposed to radiation
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Attenuation of roentgen rays by tissues exposed to radiation
Question 37
Question
What is the meaning of "computed" in name of CT (computed tomography)?
Answer
-
Calculation of radiation dose
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Control of the scanning process
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Formation of the final image
Question 38
Question
Computed tomography uses higher anode voltage compared to conventional roentgenography because
Answer
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Patients are placed further away from x-ray source
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Rotation of x-ray tube exposes more massive parts of patients body radiation
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CT x-ray detectors are less sensitive
Question 39
Question
CT exposes pateints to higher radiation doses compared to conventional roentgenography (x-ray imaging) because:
Question 40
Question
Radionuclides used in "in vivo" radionuclide diagnostics are:
Answer
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Alpha-radionuclides
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Beta-radionuclides
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Gamma-Radionuclides
Question 41
Question
What type of radioactivity is related to SPECT radionuclide diagnostics:
Question 42
Question
Alpha-rays are a beam of:
Answer
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Electrons
-
Helium nuclei
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Positrons
Question 43
Question
Radiopharmaceuticals are:
Answer
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Contrast substances used in MRI
-
Contact gels used in ultrasound diagnostics
-
Chemical compounds containing radioactive isotopes
Question 44
Question
The following quantity participates in the law of radioactive decay:
Question 45
Question
Half-life T1/2 is defined as:
Answer
-
Energy of gamma-radiation
-
Probability of radioactive decay
-
The time it takes for radioactivity to be reduced by half.
Question 46
Question
Isomeric transition is a type of decay that changes:
Answer
-
The atomic number Z of the element
-
The energy of the nucleus
-
The mass number A of the nucleus
Question 47
Question
Radionuclides produced in generators have:
Question 48
Question
Radionuclide generators contain:
Answer
-
Only gamma-radionuclides
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A meta-stable mother radionuclide
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A metastable daughter radionuclide
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Mother (parents) and daughter radionuclides - metastable radionuclides
Question 49
Question
Radionuclides are:
Question 50
Question
How does activity of a radio-pharmaceutical change after sterilization for intravenous application (sterilization time ignored):
Question 51
Question
Radio-pharmaceuticals used in nuclear medicine include:
Question 52
Question
Radio-pharmaceuticals used for "in vivo" diagnostics contain radionuclides with the following mode of radioactivity:
Answer
-
Isometric Transition
-
Beta minus decay
-
Alpha decay
Question 53
Question
Time required for intial activity A0 for a radioactive source to decay to 10% is between:
Answer
-
1 and 2 half-lives
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2 and 3 half-lives
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3 and 4 half-lives
-
4 and 5 half-lives
Question 54
Question
The decay constant for 182TA is 0.006 day-1. Which is its half life:
Answer
-
0.006 days
-
83 days
-
115 days
-
167 days
Question 55
Question
The phenomenon of radioactivity is associated with:
Question 56
Question
Electron capture involves:
Answer
-
An electron combining with a neutron
-
A neutron being ejected from the nucleus
-
An electron combining with a proton
-
An electron being ejected from the nucleus
Question 57
Answer
-
Z and A are unchanged
-
Z decreases by 4 and A decreases by 2
-
Z decreases by 2 and A decreases by 4
-
Z decreases by 4 and A decreases
Question 58
Question
Isomeric transition involves:
Answer
-
The emission of a gamma-ray
-
The conversion of a neutron to a proton
-
The conversion of a proton to a neutron
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Electron Capture
Question 59
Question
An alpha-particle consists of:
Answer
-
One proton and two neutron
-
Two proton and one neutron
-
Two proton and two neutron
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One proton and One neutron
Question 60
Question
For pair production interactions it is true that:
Answer
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Have no energy threshold
-
Occur near the electric field of the nucleus
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Produce 1.022 MeV annihilation radiation
-
Are important in diagnostic radiology
-
All of the above
Question 61
Question
99Tc-m has a half-life t1/2 = 6h. What is the approximate value of 99tc-m decay constant:
Answer
-
0.12 sec-1
-
0.12 min-1
-
0.12 hr-1
Question 62
Question
After 40 half-lives have elapsed, the activity A of radionuclide is equal to:
Answer
-
A0/40
-
A0/(2*40)
-
A0/(2 40)
Question 63
Question
Polonium-210 has a half-life of 4.5 months, and decays into the stable daughter isotope of lead-206. By measuring the proportion of polonium to lead in a sample, one can establiosh the production date of polonium. If the proportion is 1:15 (Po:Pb), how many months have elapsed since production date?
Question 64
Question
What type of radiation can NOT be detected with scintillation detector?
Answer
-
Alpha particles
-
Beta Particles
-
Gamma Rays
Question 65
Question
Ionizing radiation used for "In vivo" radionuclide diagnostics:
Question 66
Question
Which quantity is NOT a parameter of radionuclides:
Answer
-
Activity A
-
Half-Life T1/2
-
Radiation yield
-
Decay constant
Question 67
Question
Activity A is a parameter of:
Answer
-
Laser radiation
-
Radionuclides
-
Radioactive sources
Question 68
Question
Why is technetium-99m (99mTC) preferred over iodine-131 (131-I) for thyroid gland diagnostics?
Answer
-
99mTC is more cost-effective
-
99mTC has fewer side effects
-
99mTC is a "pure" gamma source and the radiation is orders of magnitude less
-
Natural deposits of 99mTC exists in some tissues
Question 69
Question
1987 an old radiotherapy source of cesium-137 (T1/2 = 30 years) was stolen from an abandoned hospital in the brazilian city of goiania. It was subsequently handled by many people, resulting in four deaths and 249 cases of high radiation exposure. If the activity of the source was 74TBq (Terebecquerels) in 1971, what was the activity in the time of the accident?