Medical Imaging Flashcards
CAT-scan tomographies are taken in which anatomical plane?
a. Sagital
b. Transverse
c. Frontal
d. Parasagittal
b. Transverse
The position of spectral lines of characteristic X-rays depends on…
a. The accelerating voltage
b. The type of anode material
c. The type of cathode material
d. The temperature of the cathode
b. The type of anode material
What is the unit of mass attenuation coefficient?
a. l/cm
b. g/cm2
c. cm2/g
d. W/cm2
c. cm2/g
The reflection of ultrasound
a. Is fundamental in aquiring the diagnostic information
b. Decreases the sharpness of the image, so it should be avoided
c. Depends only on the stiffness of the reflecting surface
d. Depends only on the angle of incidence of the ultrasound
a. Is fundamental in aquiring the diagnostic information
Why are the fetal hears sounds audible during Doppler US examination?
a. Because the frequency of the reflected sound falls in the audible range
b. Because the Doppler detector operates as a microphone
c. Because the difference of the incident and reflected frequency falls in the audible range
d. Because the ratio of incident and reflected frequency falls within the audible range
c. Because the difference of the incident and reflected frequency falls in the audible range
Select the correct statement
a. Both SPECT AND PET are anatomical imaging methods
b. We detect photons in case of both SPECT and PET
c. In case of PET we detect directly positrons
d. Isotopes used in PET have long half life
b. We detect photons in case of both SPECT and PET
What is the advantage of multimodal imaging?
a. It combines two anatomical imaging methods (CT, MRI) to indicate accurate anatomical details
b. It does not have any due to the low number of multimodal contrast materials
c. It combines functional imaging on the level of cellular processes with accurate anatomical localization
d. It is just a fashionable diagnostic trend without any apparent advantages
c. It combines functional imaging on the level of cellular processes with accurate anatomical localization
Which of the following isotopes is NOT gamma emitting?
a. I-123
b. I-131
c. Tc-99m
d. F-18
d. F-18
What is the aim of the so called windowing method?
a. It means the application of a certain filter
b. To display a narrower range of observed values
c. To snatch a detail of the image
d. To enlarge a detail of the image
b. To display a narrower range of observed values
Select the wrong statement on spin-spin relaxation
a. It is also called T2 relaxation
b. It refers to the interaction between an elementary magnet and its environment
c. We measure the temporal change of magnetic vector projection perpendicular to the external magnetic field
d. The amplitude of the measured signal decreases with time
b. It refers to the interaction between an elementary magnet and its environment
An ultrasound diagnostic device has a 3.5 and a 5 MHz transducer. Which of them has greater effective range?
a. The one with 3.5 MHz
b. The one with 5 MHz
c. Their ranges are equal
d. Range depends on acoustic impedance
a. The one with 3.5 MHz
The basis of ultrasonic imaging:
a. Is the reflection of ultrasound on the boundary between tissues of different acoustic impedance
b. Is the difference in ultrasound absorption of different tissues
c. Is the change in ultrasound speed and wavelength in different tissues
d. Is the thermal effect of ultrasound
a. Is the reflection of ultrasound on the boundary between tissues of different acoustic impedance
During contrast manipulation
a. The difference between the brightest and darkest pixels displayed on the image does not change
b. The difference between the brightest and darkest pixels displayed on the image either decreases or increases
c. The difference between the brightest and darkest pixels displayed on the image increases always
d. The difference between the brightest and darkest pixels displayed on the image decreases always
b. The difference between the brightest and darkest pixels displayed on the image either decreases or increases
Select the correct statement:
a. US is high frequency electromagnetic radiation
b. US is a mechanical wave with wavelength much longer than that of the audible sound range
c. US is a mechanical wave with frequencies much less that that of the audible sound range
d. US is a mechanical wave with frequencies many times ten-thousand Hz or even more
d. US is a mechanical wave with frequencies many times ten-thousand Hz or even more
Which statement is false?
a. Normally alpha-emitting isotope is used in nuclear imaging for its sufficient distance in body tissue
b. Purely gamma radiating isotopes are preferred in isotope diagnostics to avoid the unnecessary exposure to alpha and beta radiation
c. One way of producing pure gamma radiating isotopes is the technetium generator
d. Tc-99m is an ideal radioisotope for diagnostic imaging
a. Normally alpha-emitting isotope is used in nuclear imaging for its sufficient distance in body tissue
Which statement is correct?
a. Bremsstrahlung is electromagnetic radiating with continuous spectrum produced by the deceleration of high velocity charged particles
b. Bremsstrahlung is electromagnetic radiation with line spectrum produced by deceleration of high velocity charged particles
c. Bremsstrahlung is produced after the ionization when electrons accelerated to high energies collide with electrons in the anode material
d. The position of the maximum point of Bremsstrahlung spectrum is characteristic of the anode material
a. Bremsstrahlung is electromagnetic radiating with continuous spectrum produced by the deceleration of high velocity charged particles
What is the advantage of multimodal imaging?
a. Allows integration of the strengths of individual modalities (functional and anatomical), while overcoming their limitations
b. It has no advantage other than being cost-effective
c. It is easier to use than other imaging techniques
d. At the moment it has no advantage as multimodal contrast material does not exist
a. Allows integration of the strengths of individual modalities (functional and anatomical), while overcoming their limitations
What does the absorption coefficient of ultrasound depend on linearly?
a. On the wavelength of the ultrasound
b. On the pulse repetition frequency
c. On the frequency of the ultrasound
d. On the thickness of the layer of the medium
c. On the frequency of the ultrasound
Optical imaging is used for what purpose even today?
a. For nothing
b. For the examination of tympanic cavity
c. For the examination of renal function
d. For ocular examination (with OCT technique)
d. For ocular examination (with OCT technique)
What isotope would you use for a SPECT examination?
a. Beta(-)radiation isotope
b. Beta(+)radiation isotope
c. Gamma radiation isotope
d. SPECT does not use isotopes
c. Gamma radiation isotope
In which technique is microbubble contrast material used?
a. SPECT
b. PET
c. MRI
d. Sonography
d. Sonography
What can lead to an artifact in a CT-image?
a. Metal plates
b. Attenuation of X-rays due to air in the lungs
c. Usage of a contrast material
a. Metal plates
Which technique can NOT be used to increase image quality?
a. Convolution
b. Median Filtration
c. Filtration with a Gaussian kernel
d. Fourier transformation
c. Filtration with a Gaussian kernel
What is the definition of acoustic impedance?
a. It is the change of the propagation speed of US when the beam enters a new medium
b. The change of the intensity of US radiation upon entering a new medium
c. The ratio of the incident and reflected intensity
d. The product of the speed of propagation and the density of the medium
d. The product of the speed of propagation and the density of the medium
What makes Doppler US-examination suitable for blood flow rate determination?
a. The absorption of ultrasound depends on the flow rate
b. The flow rate depends on the diameter of the blood vessel
c. The frequency shift of scattered ultrasound depends on the speed of flowing cells
d. The reflectance depends on the flow rate
c. The frequency shift of scattered ultrasound depends on the speed of flowing cells
Which radiation is NOT ionizing radiation?
a. α-radiation
b. γ-radiation
c. ultrasound radiation
d. ultraviolet radiation
c. ultrasound radiation
Which statement is correct for molecular imaging?
a. It is a type of anatomical imaging
b. Cells and processes at cellular level can be examine ex-vivo
c. It is an expensive technique
d. Cells and processes at cellular level can be examined in-vivo
d. Cells and processes at cellular level can be examined in-vivo
What is the disadvantage of the thallium-201 heart scan?
a. The atomic number of Tl-201 is too high so it is only poorly accumulated in the heart
b. It poses relatively high exposure
c. It doesn’t remain in the heart for long so it can only be used throughout a few ECG- cycles
d. The radiation is absorbed poorly so that image of the heart cannot be reconstructed well
b. It poses relatively high exposure
What does the absorption coefficient of ultrasound depend on linearly?
a. On the wavelenght of US
b. On the pulse repitition frequency
c. On the frequency of the US
d. On the thickness of the layer of the medium
c. On the frequency of the US
What is the piezoelectric effect?
a. The deformation of certain crystals leads to electric currents
b. Certain crystal are deformed by electricity
c. The volume of certain crystals is reduced by electricity
d. Certain crystals generate an alternating current due to increased pressure
a. The deformation of certain crystals leads to electric currents
Synchronisation of the respiratory cycle
a. Is only possible in a PET
b. Increases the quality of the image because all pictures are in same phase
c. Reduces the radiation dose required during the imaging process
b. Increases the quality of the image because all pictures are in same phase
What does an image contain?
a. All information of an object
b. The optical characteristics of an object
c. The spatial distribution of some quality of the object
d. It does not provide any information
c. The spatial distribution of some quality of the object
What is the unit of acoustic impedance?
a. It is unitless
b. Kg/(m2*s)
c. Cm/g2
d. Photons
b. Kg/(m2*s)
What is meant by voxel?
a. Volumetric unit in imagery
b. Pixels of an MRI
c. Pixel formation
d. Unit of magnetic moment
a. Volumetric unit in imagery
Pick the correct statement
a. Fourier-transformation can be used advantageously in diagnostic image formation to identify sharp contrast changes or to spot edges
b. Fourier-transformation describes the information content of a two-dimensional image with a one-dimensional frequency function
c. According to Fourier’s principle every periodic function can be reproduced by the product of a sine function and its overtones
d. Fourier-transformation can be used advantageously in diagnostic image formation to precisely reproduce lost image information
a. Fourier-transformation can be used advantageously in diagnostic image formation to identify sharp contrast changes or to spot edges
Which statement is true?
a. Resolution is defined by the number of lines that are identifiable in 1 cm
b. Resolution is defined as the shortest distance between two points on a specimen that can still be distinguished as two separate points
c. Resolution is defined as the highest magnification of a microscope
d. Resolution is not used in the field of radiology, instead sensitivity is used
b. Resolution is defined as the shortest distance between two points on a specimen that can still be distinguished as two separate points
What information does an MRI examination give?
a. Proton density
b. Mass attenuation coefficient
c. Linear attenuation coefficient
d. Acoustic impedance
a. Proton density
In which case does not the spectral composition of x-radiation change?
a. If the accelerated voltage is changed
b. If the anode current is changed
c. If the anode material is changed
d. If a filter is used
b. If the anode current is changed