cyberbabooshka/nlp4ed · Datasets at Hugging Face

question stringlengths 4 1.87k	choices sequencelengths 2 27	answer_index int64 0 9	answer stringclasses 9 values
The ratio T1 / T2 = 10 was measured for a 1H resonance on a 600 MHz spectrometer. What is the value of tau c?	[ "0.52 ns", "1.13 ns", "1.38 ns", "2.05 ns" ]	1	B
Diagnostic ultrasound is defined as a sound with a frequency of:	[ "Greater than 20 kHz", "Greater than 0.2 MHz", "Greater than 1 MHz", "Less than 1 kHz" ]	2	C
Why are filters placed within the X-ray tube of a CT scanner?	[ "To decrease the scan time", "To remove high energy photons from the beam", "To remove low energy X-ray photons from the beam" ]	2	C
Where is hydrogen magnetization measured?	[ "Along the main magnetic field", "Perpendicular to the main magnetic field" ]	1	B
The magnetic moment of individual spin in induction field \(B_0\) depends on:	[ "Gyromagnetic ratio", "The surrounding spins of other molecules", "Magnetic field", "The temperature", "The angular momentum of the nucleus" ]	0	A
Why should you go to the bathroom before leaving the hospital after a PET scan?	[ "In order to eliminate most of the radioactive substance.", "Doctors can check the desintegration of radioactive substance after the scan.", "Urine analysis is necessary to a better interpretation of PET scan images" ]	0	A
What produces a uniform density of the radiograph called image noise?	[ "Photoelectric effect", "Filter", "Photodisintegration", "Rayleigh (coherent) scattering" ]	3	D
In an X-ray tube, electrons travel:	[ "Toward the cathode.", "Toward the anode.", "Within the nucleus of an atom." ]	1	B
Regarding the current PET/CT scanners, which of the following two statements is true?	[ "PET and CT are in the same gantry, and acquisition of PET and CT occurs simultaneously.", "After the CT scan, the PET image is acquired." ]	1	B
What are the advantages of bio-imaging compared to tissue analysis? Make sure you select all of the correct options — there may be more than one!	[ "Bioimaging allows longitudinal studies, which increases statistical power.", "Repetitive studies are possible and allow observing the evolution in the same subject.", "Bioimaging is non invasive.", "The structure of tissues can be described more precisely.", "The image acquisition is fairly fast." ]	0	A
How long does it take for the free induction decay of an NMR line with T2 = 0.5 s to decay to 1% of its initial amplitude?	[ "2.30 s", "2.90 s", "3.20 s", "3.70 s" ]	0	A
Rats have a higher glucose metabolic rate (GMR) in their brain than humans. Can we conclude they are smarter ?	[ "Yes, some studies tend to show that rats learn faster than humans.", "No, some studies indicate an inverse relationship between GMR and intelligence.", "Studies have shown that there is no correlation between GMR and intelligence" ]	1	B
Which element within the body is the most important regarding MRI?	[ "Oxygen", "Carbon", "Hydrogen" ]	2	C
You discover a mummy. Which imaging technique will you use?	[ "MRI", "PET scan", "X-ray radiography" ]	2	C
Which interaction between X-ray beam and matter results in the largest patient dose?	[ "Characteristic", "Compton's scatter", "Bremsstrahlung", "Photoelectric effect" ]	3	D
What is the optimal \(TI\) to detect changes in \(T_1\)?	[ "\\(TI = T_1\\)", "\\(TI = T_1/2\\)", "\\(TI = \\pi/2\\)" ]	0	A
Let's consider a drug distribution rate from a compartment 1 to 2. In the simplest case, this rate is assumed to be...	[ "Approximately constant", "Decreasing exponentially", "Proportional to the mass (or concentration) of the drug in compartment 1." ]	2	C
Which component of an MRI system allows to choose exactly where in the body to acquire an image?	[ "Gradient magnets", "RF pulses", "Contrast agents" ]	0	A
Compared with SE (spin echo), GRE (gradient echo) sequences use	[ "Longer \\(TR\\)", "Shorter \\(TR\\)", "Longer \\(TE\\)", "Shorter \\(TE\\)" ]	1	B
Which of the following statements is true?	[ "Is due to photoelectric absorption and Compton scatter.", "Gives the relative number of x-rays emitted at each photon energy.", "Depends only on the braking radiation.", "Is produced by electron transitions between the electron shells." ]	1	B
What are the types of coincidence events?	[ "True", "Random", "Scattered", "Multiple" ]	0	A
In a gamma camera, what is the component that "converts" the light signal in electronic signal?	[ "Dynode", "Photocatode", "Photomultiplier tube", "Scintillator crystal" ]	2	C
What is the name of the Austrian mathematician who proved in 1917 that it was possible to reconstruct a three-dimensional object from the infinite set of all of its projections?	[ "Radon", "Tsien", "Bracewell", "Cormack" ]	0	A
How long (in multiples of T1) is it necessary to wait for Δn(t) to relax to 99% of Δneq??	[ "2.61 T1", "4.61 T1", "5.02 T1", "7.03 T1" ]	1	B
What is the NMR frequency of 1H in a 23.488 T magnetic field?	[ "1000.0 Hz", "1000.0 kHz", "1000.0 MHz", "1000.0 GHz" ]	2	C
Which phenomena does the term "beam hardening" describe?	[ "The decrease in average photon energy of a heterogeneous X-ray beam", "The increase in average photon energy of a homogeneous X-ray beam", "The increase in average photon energy of a heterogeneous X-ray beam", "None of the above" ]	2	C
When incoming electrons interacts with bound electrons in the X-ray target, ionization of the atom can occur...	[ "if the absolute energy transferred exceeds the absolute binding energy of the shell involved.", "as well as emission of alpha and beta particles.", "and gamma ray emission too.", "when the kinetic energy of the incoming electrons is less than the binding energy of the shell involved." ]	0	A
For each of the following compounds determine which protons are magnetically equivalent:	[ "benzene", "the 2,5 protons in furan", "F2C=C=CH2" ]	0	A
How is termed the fraction of attenuated incident photons per unit thickness of a material?	[ "Linear attenuation coefficient", "Mass absorption coefficient", "Coefficient of scattering", "Mean attenuation ratio" ]	0	A
Predict the total number of lines in the 1H spectrum of CH3Cl	[ "0", "1", "2", "3" ]	1	B
How is called the reduction of intensity when an X-ray beam interacts with matter?	[ "Scatter", "Attenuation", "Transmission", "Differential absorption" ]	1	B
In a "90 degree impulsion" when the RF pulse is applied...	[ "The excess of protons spins parallel to \\(\\vec B_0\\) disappears.", "Proton spins precess in phase.", "All of the above" ]	2	C
Why using a rotating reference frame to describe motion of magnetization?	[ "Because the formulas were developped historically considering rotating frame.", "To simplify the complex motion of precessing spins.", "It is the international standard." ]	1	B
Which action allows the formation of a spin echo?	[ "Reversing the direction of \\(\\vec B_0\\).", "Flipping proton direction by a radiofrequency pulse.", "Applying a negative magnetic field gradient." ]	1	B
To null the signal from a particular tissue with an IR sequence, one should choose TI based on what?	[ "The proton density of the tissue", "The \\(T_1\\) value of the tissue", "The \\(T_2\\) value of the tissue", "The \\(T_2^*\\) value of the tissue", "The precession frequency of the tissue" ]	1	B
Which of the following imaging parameter allows fat-water phase differences in MRI?	[ "TR in a spin echo (SE) sequence", "TE in a spin echo (SE) sequence", "TR in a gradient echo (GRE) sequence", "TE in a gradient echo (GRE) sequence", "TR in either SE or GRE sequence", "TE in either SE or GRE sequence" ]	3	D
Predict which of the following compounds has the highest and which the lowest 1H chemical shift: CH3Br, CH2Br2 and CHBr3. (from highest to lowest)	[ "CH3Br > CH2Br2 > CHBr3", "CHBr3 > CH2Br2 > CH3Br", "CH2Br2 > CHBr3 > CH3Br", "They have all the same 1H chemical shift" ]	1	B
The three most common parameters used to measure the "quality" of an image are…	[ "The spatial resolution, the sensitivity and signal-to-noise ratio.", "The SNR, the spatial resolution and contrast-to-noise ratio.", "The image noise, the spatial resolution and signal-to-noise ratio." ]	1	B
X-ray detection in Emission Tomography involves...	[ "A beta camera composed of PMT and scintillating crystal", "A measure at 180 degrees simultaneously", "An x-ray tube and a circular detector ring", "Collimation, scintillation and amplification" ]	3	D
An MRI system creates an image when:	[ "All the hydrogen atoms in the body precess around the same axis.", "Hydrogens atoms align to the magnetic field.", "After excitation, the hydrogen atoms go back to their initial position, releasing energy." ]	2	C
What is the name given to the relaxation process due to a transfer of energy from the nuclear spin system to neighboring molecules?	[ "Spin - lattice relaxation", "Spin - spin relaxation" ]	0	A
Which of the following is not directly ionizing radiation?	[ "Positrons", "\\(\\alpha-\\)particles", "Neutrons", "Protons" ]	2	C
When was the first MRI human scan performed?	[ "1952", "1965", "1977", "1985" ]	2	C
What is the cause of the light areas seen on a radiograph (low optical density), such those corresponding to bone?	[ "Photoelectric effect", "Image noise", "Compton interactions" ]	0	A
What is the essential and biggest component of an MRI scanner?	[ "Magnet", "Digitizer", "Imager" ]	0	A
When a hydrogen atom in a magnetic field absorbs radiation energy...	[ "Frequency of precession of the nucleus increases.", "The magnetic moment vector spins faster.", "The magnetic moment vector of nucleus \"flips\" so that it now opposes the applied field." ]	2	C
On a chest radiograph, lungs are mainly imaged because of differences in...	[ "Mass density", "Absorption coefficient", "Attenuation coefficient" ]	0	A
The following data were measured in an inversion recovery experiment: tau [s]: 2.0 , 5.0 , 10.0 , 20.0 , 100.0 with their respective signal intensities Signal(tau): -0.702 , -0.336 , 0.107 , 0.601 , 1.000. Determine the value of T1.	[ "10.5 s", "12.4 s", "15.6 s", "18.1 s" ]	1	B
How is called a digital imaging system's ability to distinguish between similar tissues?	[ "Spatial resolution", "Good SNR", "Contrast resolution" ]	2	C
The recorded sharpness or detail of structures on the image is known as...	[ "SNR", "Contrast", "Spatial resolution" ]	2	C
In Doppler effect, which incident angle (in degree) results in no shift?	[ "180", "90", "45", "0" ]	1	B
How is called the difference in brightness between light and dark areas of an image?	[ "Spatial resolution", "SNR", "Contrast" ]	2	C
What is the NMR frequency of 13C in a 23.488 T magnetic field?	[ "1000.0 MHz", "251.5 MHz", "503.0 MHz", "754.5 MHz" ]	1	B
The aromatic region of the 13C{1H} spectrum of N-methylaniline contains six lines at low temperature. How many lines might be expected at high temperature??	[ "2", "4", "6", "8" ]	1	B
What is the NMR frequency of 1H in the Earth's magnetic field (50 micro Tesla)?	[ "1.065 kHz", "2.129 kHz", "3.194 kHz", "4.258 kHz" ]	1	B
How many distinct chemical shifts would you expect to find in the 13C spectrum of 2-methylbutane?	[ "1", "2", "3", "4" ]	3	D
In order to obtain a signal in MRI experiment, what is the first step?	[ "Apply an RF pulse along \\(\\vec B_0\\)", "Change the amplitude of \\(\\vec B_0\\)", "Apply an RF pulse in a different direction from \\(\\vec B_0\\)", "Apply a magnetic field gradient" ]	2	C
Which of the following decreases the noise of the CT image?	[ "Decrease in dose", "Decrease in slice thickness", "Increase in matrix size", "Decrease in matrix size" ]	3	D
The 1H spectrum of CH2D2 contains five lines. What are their relative intensities?	[ "1:2:2:2:1", "1:1:1:1:1", "1:2:3:2:1", "1:1:2:1:1" ]	2	C
A characteristic feature of a projection radiograph is:	[ "Poor spatial resolution", "Lengthy data acquisition", "Tissue superimposition" ]	2	C
What is \(K_\alpha\) transition?	[ "The ionization of a K shell electron.", "It leads to the emission of Bremsstrahlung.", "It leads to the emission of characteristic radiation." ]	2	C
Predict the total number of lines in the 1H spectrum of 1,2-dichloro-3,4-dibromobenzene	[ "1", "2", "3", "4" ]	3	D
When X-rays interact with materials, they are able to:	[ "Cause substances to fluoresce.", "Remove an electron from an atom.", "Cause chemical changes that may lead to cells disfunctions." ]	0	A
Which of the following molecules are typical tracers for SPECT?	[ "F-18", "O-15", "99m-Tc", "Tl-201", "C-11" ]	2	C
Let's consider two systems of particles (with different gyromagnetic ratio) of spin ½ in a magnetic field \(\vec B_0\). The total population as well as temperature in each system are the same. According to Boltzmann distribution :	[ "The system with highest \\( \\gamma \\) has more down spins than the system with lowest \\( \\gamma \\).", "The system with highest \\( \\gamma \\) has less down spins than the system with lowest \\( \\gamma \\).", "The distribution is exactly the same : it does not depend on \\(\\gamma\\)." ]	1	B
NMR stands for	[ "Nuclear Moment of Resonance", "Non Magnetic Radiation", "Nuclear Magnetic Radiation", "Nuclear Magnetic Resonance" ]	3	D
>>In spin echo sequences, what do TR and TE refer to?	[ "TR: the spacing between successive 90-degree pulses; TE: time between the 90-degree pulse and the spin echo", "TR: the spacing between successive 90-degree pulses; TE: the spacing between the 90-degree pulse and the 180-degree pulse", "TR: time before the 90-degree pulse and the spin echo; TE: the spacing between successive 90-degree pulses", "TR: the spacing between the 90-degree pulse and the 180-degree pulse; TE: the spacing between successive 90-degree pulses" ]	0	A
What can improve SNR in MRI if it is increased?	[ "Bandwidth", "Gradient strength", "Acquisition time" ]	2	C
In FDG PET, how is called the factor that takes into account that what one is measuring with deoxyglucose is not the real glucose molecule but an analog of glucose?	[ "The Lumped constant", "The Fick constant" ]	0	A
What is the duration of a 1H 90° pulse when B1 = 1.00 mT?	[ "4.12 microseconds", "5.87 microseconds", "9.82 microseconds", "12.45 microseconds" ]	1	B
In diagnostic X-ray systems, filters are used to "harden" the beam. This process is mainly due to:	[ "Coherent scattering.", "Photoelectric effect.", "Compton effect.", "Pair production." ]	1	B
What is the form of the majority of energy produced by electrons in X-rays tubes?	[ "Light", "Sound", "X-ray energy", "Heat" ]	3	D
Which MR imaging parameter determines how much of T1 (longitudinal) recovery occur?	[ "TR", "TE", "Bandwidth (BW)", "Number of excitations", "Gradient intensity" ]	0	A
Let's consider two media: the speed of sound in the two media is different and impedances of these two media are identical. A sound pulse reaches the boundary between these two media with normal incidence. Does the reflection occur?	[ "Yes", "No" ]	1	B
Which of the following imaging modalities is/are ionizing?	[ "X-rays", "CT (Computed tomography)", "MRI (Magnetic resonance imaging)", "US (Ultrasounds)", "PET (Positron emission tomography)", "SPECT (Single photon emission computed tomography)" ]	0	A
What is true concerning scatter radiation?	[ "They reduce contrast resolution", "They contribute to the image formation." ]	0	A
Where does the annihilation of positron and electron take place?	[ "In the radionuclide emitting the positron", "At a short distance from the radionuclide" ]	1	B
How does the particular dendritic conductance of CA1 pyramidal neurons influence the integration of the signals from two synapses, one close to the soma and one close to the distal dendrite, activated with a time delay?	[ "Both signals are integrated to generate an AP in the soma if the delay is short (up to 20 ms) and the distal synapse is activated first or very shortly after the proximal one", "Both signals are integrated to generate an AP in the soma even when the delay is long (up to 50 ms)", "Each of the two signals generate a separate AP in the soma except when the time delay is very short (less than 10 ms), in which case a single AP is generated", "Both signals are integrated to generate an AP in the soma if the delay is short (up to 20 ms) and the proximal synapse is activated first or very shortly after the distal one" ]	0	A
A neuron can be considered as a dipole. Why does the amplitude of the extracellular potential fall proportionally to the square of the distance from the dipole it originates in?	[ "Because the current is divided by the square of the distance to obtain the extracellular potential in the formula", "Because as one moves further away from the dipole, current and return current cancel each other out more and more in addition to the decrease in amplitude that is proportional to the distance", "Because the sum of all currents acting on an extracellular location is weighted by a multiple of the squared distance between compartment and the extracellular location", "It does not fall proportionally to the square of the distance, but proportionally to the distance between the dipole and the extracellular location" ]	1	B
Which method can be used to link a broad range of different time and spatial scales when studying the brain?	[ "Patch clamp", "PET imaging", "Modeling and simulation", "Long-term clinical studies" ]	2	C
How are different regions of the hippocampus connected to each other?	[ "The connections are largely reciprocal; if region A projects to region B, region B also projects to region A", "The connections are mainly unidirectional along a stream", "The connections allow signals to spread along the longitudinal axis of the hippocampus", "The connections keep the signals mainly in one slide of the longitudinal axis called a lamella" ]	1	B
What are fixed point attractors in nonlinear recurrent networks?	[ "Specific neurons that are always activated", "Stable patterns of activity towards which other patterns converge", "Memory traces, if the can be learned by the network", "Connections between neurons that get consolidated upon recall" ]	1	B
What are the two main ions contributing to the generation of an action potential?	[ "Na+ and Cl-", "Ca2+ and Cl-", "H+ and K+", "Na+ and K+" ]	3	D
Which important point must be considered when populating the region to model?	[ "The types of cells present in the region", "The shape of the volume to populate", "The density of each cell type", "The location and orientation of the cells in the volume" ]	0	A
What determines the firing pattern of a neuron in response to step current injections?	[ "The length of its axon", "Its expression of different voltage-gated ion channels", "Which neurotransmitter it expresses", "The post-synaptic domain of the cells that it targets" ]	1	B
What does simulating a neuron help to understand?	[ "Dendritic integration", "The neural code", "The role of the biophysical make-up of a neuron", "Potentially all of the above, depending on the type of model used" ]	3	D
Which statement about CA1 pyramidal neurons are true?	[ "The KA density increases with the distance to the soma, the Ih density stays constant", "The density of both K and non-specific ion channels increases when the distance to the soma increases", "They receive two main independent inputs, one from the entorhinal cortex and one from the olfactory bulb that arrive at different locations", "They receive two main inputs that both originate from the same signal in the entorhinal cortex and arrive at different locations with a time delay" ]	1	B
Which property of the hippocampus makes it a good model to study the nervous system?	[ "The connections on the hippocampus are almost unidirectional", "The synapses are highly plastic", "Hippocampal neurons can be grown in culture", "All of the above" ]	3	D
What is true about gamma and theta oscillations?	[ "Theta oscillations are persistent, while gamma oscillations are transient", "Both types of oscillations can be transient or persistent", "The same receptors can activate or block a type of oscillations", "Different receptors activate or block each type of oscillations", "Not all types of oscillations can be observed in all hippocampal regions", "Gamma oscillations can have a broad range of high frequencies" ]	1	B
>>The factors listed below influence either presynaptic or postsynaptic specificity. Which ones affect postsynaptic specificity?	[ "The dynamic release properties", "The number of receptors", "Postsynaptic properties", "The release probability", "The type of receptors", "The number of release sites" ]	1	B
How are somatic and dendritic conductances related to the firing pattern of a cell?	[ "Each cell type has a fixed firing pattern that results from all individual cells of the same type having the same somatic and dendritic conductances", "Each combination of conductances generate a different firing behavior", "Specific conductances must be at certain levels in order to generating a defined firing pattern", "Several combinations of conductances are able to reproduce the same firing behavior" ]	2	C
How does the calculation of extracellular potentials help with experimental design?	[ "Mismatches between simulations and experimental data highlight mistakes in experimental data and show how experiments need to be modified in order to match the model", "It doesn’t help experimental design, but generates data so that experiments are not necessary anymore in order to answer biological questions", "Because the calculation of extracellular potentials allows separating the contribution of each neuron to the signal, it can inform on where to place electrodes to measure specific activities", "All of the above" ]	2	C
What do the simple networks explaining gamma oscillations and ripples not have in common?	[ "The same connectivity pattern", "A high number of basket cells", "Direct auto-inhibitory feedback loops acting on single basket cells", "All of the above" ]	3	D
Which statement concerning the firing pattern of neurons is true?	[ "There is a correlation between the firing pattern and the calcium binding protein content.", "There is an absolute correlation between the firing pattern and the calcium binding protein content of all interneurons.", "All fast-spiking cells express the potassium channel Kv3.1", "Basket cells are the only fast spiking cells in the hippocampu" ]	0	A
What is the effect of the particular dendritic conductance of CA1 pyramidal neurons on back-propagating APs?	[ "AP amplitude along the dendrites increases as the distance to the soma increases", "AP amplitude along the dendrites decreases as the distance to the soma increases", "AP amplitude stays constant along the dendrites over the distance to the soma", "AP amplitude along the axon decreases as the distance to the soma increases" ]	1	B
How can modeling help with sparse data?	[ "By identifying principles allowing to predict missing data", "By guiding experimental design in highlighting missing data", "By finding connections between data types and data points allowing interpolation of missing data", "All of the above" ]	3	D
When do the synapses in CA3 need to be plastic?	[ "For pattern separation", "For memory retrieval", "For learning", "All of the above" ]	2	C
Which statement about hippocampal synaptic plasticity, network oscillations and neuromodulation is true?	[ "Network oscillations in the hippocampus endow it with cognitive functions like learning and memory", "Neuromodulation in the hippocampus gate synaptic plasticity and enhance network oscillations", "The oscillations observed in the hippocampus are similar to those observed in other parts of the cortex", "All of the above" ]	3	D
Which statements about cable theory are true?	[ "The conductance for each ion stays the same all along the axon and dendrites", "It quantifies the propagation of a signal along the axon and dendrites", "The change in voltage over the distance is related to the change in voltage over time", "The neuron is discretized to form several coupled compartments corresponding to parts of the axon and dendrites" ]	1	B
Why is a massive increase in model complexity a challenge?	[ "Because computational capacity has not increased enough during the last century", "Because existing scientific codes like NEURON are not adapted to use massively parallel systems", "Because neuron networks cannot be simulated using parallel systems", "It is not a challenge; very large models can be simulated on normal desktop computers since desktop computers have become much faster and have large storage capabilities" ]	1	B

The ratio T1 / T2 = 10 was measured for a 1H resonance on a 600 MHz spectrometer. What is the value of tau c?

[ "0.52 ns", "1.13 ns", "1.38 ns", "2.05 ns" ]

1

B

Diagnostic ultrasound is defined as a sound with a frequency of:

[ "Greater than 20 kHz", "Greater than 0.2 MHz", "Greater than 1 MHz", "Less than 1 kHz" ]

2

C

Why are filters placed within the X-ray tube of a CT scanner?

[ "To decrease the scan time", "To remove high energy photons from the beam", "To remove low energy X-ray photons from the beam" ]

2

C

Where is hydrogen magnetization measured?

[ "Along the main magnetic field", "Perpendicular to the main magnetic field" ]

1

B

The magnetic moment of individual spin in induction field \(B_0\) depends on:

[ "Gyromagnetic ratio", "The surrounding spins of other molecules", "Magnetic field", "The temperature", "The angular momentum of the nucleus" ]

0

A

Why should you go to the bathroom before leaving the hospital after a PET scan?

[ "In order to eliminate most of the radioactive substance.", "Doctors can check the desintegration of radioactive substance after the scan.", "Urine analysis is necessary to a better interpretation of PET scan images" ]

0

A

What produces a uniform density of the radiograph called image noise?

[ "Photoelectric effect", "Filter", "Photodisintegration", "Rayleigh (coherent) scattering" ]

3

D

In an X-ray tube, electrons travel:

[ "Toward the cathode.", "Toward the anode.", "Within the nucleus of an atom." ]

1

B

Regarding the current PET/CT scanners, which of the following two statements is true?

[ "PET and CT are in the same gantry, and acquisition of PET and CT occurs simultaneously.", "After the CT scan, the PET image is acquired." ]

1

B

What are the advantages of bio-imaging compared to tissue analysis? Make sure you select all of the correct options — there may be more than one!

[ "Bioimaging allows longitudinal studies, which increases statistical power.", "Repetitive studies are possible and allow observing the evolution in the same subject.", "Bioimaging is non invasive.", "The structure of tissues can be described more precisely.", "The image acquisition is fairly fast." ]

0

A

How long does it take for the free induction decay of an NMR line with T2 = 0.5 s to decay to 1% of its initial amplitude?

[ "2.30 s", "2.90 s", "3.20 s", "3.70 s" ]

0

A

Rats have a higher glucose metabolic rate (GMR) in their brain than humans. Can we conclude they are smarter ?

[ "Yes, some studies tend to show that rats learn faster than humans.", "No, some studies indicate an inverse relationship between GMR and intelligence.", "Studies have shown that there is no correlation between GMR and intelligence" ]

1

B

Which element within the body is the most important regarding MRI?

[ "Oxygen", "Carbon", "Hydrogen" ]

2

C

You discover a mummy. Which imaging technique will you use?

[ "MRI", "PET scan", "X-ray radiography" ]

2

C

Which interaction between X-ray beam and matter results in the largest patient dose?

[ "Characteristic", "Compton's scatter", "Bremsstrahlung", "Photoelectric effect" ]

3

D

What is the optimal \(TI\) to detect changes in \(T_1\)?

[ "\\(TI = T_1\\)", "\\(TI = T_1/2\\)", "\\(TI = \\pi/2\\)" ]

0

A

Let's consider a drug distribution rate from a compartment 1 to 2. In the simplest case, this rate is assumed to be...

[ "Approximately constant", "Decreasing exponentially", "Proportional to the mass (or concentration) of the drug in compartment 1." ]

2

C

Which component of an MRI system allows to choose exactly where in the body to acquire an image?

[ "Gradient magnets", "RF pulses", "Contrast agents" ]

0

A

Compared with SE (spin echo), GRE (gradient echo) sequences use

[ "Longer \\(TR\\)", "Shorter \\(TR\\)", "Longer \\(TE\\)", "Shorter \\(TE\\)" ]

1

B

Which of the following statements is true?

[ "Is due to photoelectric absorption and Compton scatter.", "Gives the relative number of x-rays emitted at each photon energy.", "Depends only on the braking radiation.", "Is produced by electron transitions between the electron shells." ]

1

B

What are the types of coincidence events?

[ "True", "Random", "Scattered", "Multiple" ]

0

A

In a gamma camera, what is the component that "converts" the light signal in electronic signal?

[ "Dynode", "Photocatode", "Photomultiplier tube", "Scintillator crystal" ]

2

C

What is the name of the Austrian mathematician who proved in 1917 that it was possible to reconstruct a three-dimensional object from the infinite set of all of its projections?

[ "Radon", "Tsien", "Bracewell", "Cormack" ]

0

A

How long (in multiples of T1) is it necessary to wait for Δn(t) to relax to 99% of Δneq??

[ "2.61 T1", "4.61 T1", "5.02 T1", "7.03 T1" ]

1

B

What is the NMR frequency of 1H in a 23.488 T magnetic field?

[ "1000.0 Hz", "1000.0 kHz", "1000.0 MHz", "1000.0 GHz" ]

2

C

Which phenomena does the term "beam hardening" describe?

[ "The decrease in average photon energy of a heterogeneous X-ray beam", "The increase in average photon energy of a homogeneous X-ray beam", "The increase in average photon energy of a heterogeneous X-ray beam", "None of the above" ]

2

C

When incoming electrons interacts with bound electrons in the X-ray target, ionization of the atom can occur...

[ "if the absolute energy transferred exceeds the absolute binding energy of the shell involved.", "as well as emission of alpha and beta particles.", "and gamma ray emission too.", "when the kinetic energy of the incoming electrons is less than the binding energy of the shell involved." ]

0

A

For each of the following compounds determine which protons are magnetically equivalent:

[ "benzene", "the 2,5 protons in furan", "F2C=C=CH2" ]

0

A

How is termed the fraction of attenuated incident photons per unit thickness of a material?

[ "Linear attenuation coefficient", "Mass absorption coefficient", "Coefficient of scattering", "Mean attenuation ratio" ]

0

A

Predict the total number of lines in the 1H spectrum of CH3Cl

[ "0", "1", "2", "3" ]

1

B

How is called the reduction of intensity when an X-ray beam interacts with matter?

[ "Scatter", "Attenuation", "Transmission", "Differential absorption" ]

1

B

In a "90 degree impulsion" when the RF pulse is applied...

[ "The excess of protons spins parallel to \\(\\vec B_0\\) disappears.", "Proton spins precess in phase.", "All of the above" ]

2

C

Why using a rotating reference frame to describe motion of magnetization?

[ "Because the formulas were developped historically considering rotating frame.", "To simplify the complex motion of precessing spins.", "It is the international standard." ]

1

B

Which action allows the formation of a spin echo?

[ "Reversing the direction of \\(\\vec B_0\\).", "Flipping proton direction by a radiofrequency pulse.", "Applying a negative magnetic field gradient." ]

1

B

To null the signal from a particular tissue with an IR sequence, one should choose TI based on what?

[ "The proton density of the tissue", "The \\(T_1\\) value of the tissue", "The \\(T_2\\) value of the tissue", "The \\(T_2^*\\) value of the tissue", "The precession frequency of the tissue" ]

1

B

Which of the following imaging parameter allows fat-water phase differences in MRI?

[ "TR in a spin echo (SE) sequence", "TE in a spin echo (SE) sequence", "TR in a gradient echo (GRE) sequence", "TE in a gradient echo (GRE) sequence", "TR in either SE or GRE sequence", "TE in either SE or GRE sequence" ]

3

D

Predict which of the following compounds has the highest and which the lowest 1H chemical shift: CH3Br, CH2Br2 and CHBr3. (from highest to lowest)

[ "CH3Br > CH2Br2 > CHBr3", "CHBr3 > CH2Br2 > CH3Br", "CH2Br2 > CHBr3 > CH3Br", "They have all the same 1H chemical shift" ]

1

B

The three most common parameters used to measure the "quality" of an image are…

[ "The spatial resolution, the sensitivity and signal-to-noise ratio.", "The SNR, the spatial resolution and contrast-to-noise ratio.", "The image noise, the spatial resolution and signal-to-noise ratio." ]

1

B

X-ray detection in Emission Tomography involves...

[ "A beta camera composed of PMT and scintillating crystal", "A measure at 180 degrees simultaneously", "An x-ray tube and a circular detector ring", "Collimation, scintillation and amplification" ]

3

D

An MRI system creates an image when:

[ "All the hydrogen atoms in the body precess around the same axis.", "Hydrogens atoms align to the magnetic field.", "After excitation, the hydrogen atoms go back to their initial position, releasing energy." ]

2

C

What is the name given to the relaxation process due to a transfer of energy from the nuclear spin system to neighboring molecules?

[ "Spin - lattice relaxation", "Spin - spin relaxation" ]

0

A

Which of the following is not directly ionizing radiation?

[ "Positrons", "\\(\\alpha-\\)particles", "Neutrons", "Protons" ]

2

C

When was the first MRI human scan performed?

[ "1952", "1965", "1977", "1985" ]

2

C

What is the cause of the light areas seen on a radiograph (low optical density), such those corresponding to bone?

[ "Photoelectric effect", "Image noise", "Compton interactions" ]

0

A

What is the essential and biggest component of an MRI scanner?

[ "Magnet", "Digitizer", "Imager" ]

0

A

When a hydrogen atom in a magnetic field absorbs radiation energy...

[ "Frequency of precession of the nucleus increases.", "The magnetic moment vector spins faster.", "The magnetic moment vector of nucleus \"flips\" so that it now opposes the applied field." ]

2

C

On a chest radiograph, lungs are mainly imaged because of differences in...

[ "Mass density", "Absorption coefficient", "Attenuation coefficient" ]

0

A

The following data were measured in an inversion recovery experiment: tau [s]: 2.0 , 5.0 , 10.0 , 20.0 , 100.0 with their respective signal intensities Signal(tau): -0.702 , -0.336 , 0.107 , 0.601 , 1.000. Determine the value of T1.

[ "10.5 s", "12.4 s", "15.6 s", "18.1 s" ]

1

B

How is called a digital imaging system's ability to distinguish between similar tissues?

[ "Spatial resolution", "Good SNR", "Contrast resolution" ]

2

C

The recorded sharpness or detail of structures on the image is known as...

[ "SNR", "Contrast", "Spatial resolution" ]

2

C

In Doppler effect, which incident angle (in degree) results in no shift?

[ "180", "90", "45", "0" ]

1

B

How is called the difference in brightness between light and dark areas of an image?

[ "Spatial resolution", "SNR", "Contrast" ]

2

C

What is the NMR frequency of 13C in a 23.488 T magnetic field?

[ "1000.0 MHz", "251.5 MHz", "503.0 MHz", "754.5 MHz" ]

1

B

The aromatic region of the 13C{1H} spectrum of N-methylaniline contains six lines at low temperature. How many lines might be expected at high temperature??

[ "2", "4", "6", "8" ]

1

B

What is the NMR frequency of 1H in the Earth's magnetic field (50 micro Tesla)?

[ "1.065 kHz", "2.129 kHz", "3.194 kHz", "4.258 kHz" ]

1

B

How many distinct chemical shifts would you expect to find in the 13C spectrum of 2-methylbutane?

[ "1", "2", "3", "4" ]

3

D

In order to obtain a signal in MRI experiment, what is the first step?

[ "Apply an RF pulse along \\(\\vec B_0\\)", "Change the amplitude of \\(\\vec B_0\\)", "Apply an RF pulse in a different direction from \\(\\vec B_0\\)", "Apply a magnetic field gradient" ]

2

C

Which of the following decreases the noise of the CT image?

[ "Decrease in dose", "Decrease in slice thickness", "Increase in matrix size", "Decrease in matrix size" ]

3

D

The 1H spectrum of CH2D2 contains five lines. What are their relative intensities?

[ "1:2:2:2:1", "1:1:1:1:1", "1:2:3:2:1", "1:1:2:1:1" ]

2

C

A characteristic feature of a projection radiograph is:

[ "Poor spatial resolution", "Lengthy data acquisition", "Tissue superimposition" ]

2

C

What is \(K_\alpha\) transition?

[ "The ionization of a K shell electron.", "It leads to the emission of Bremsstrahlung.", "It leads to the emission of characteristic radiation." ]

2

C

Predict the total number of lines in the 1H spectrum of 1,2-dichloro-3,4-dibromobenzene

[ "1", "2", "3", "4" ]

3

D

When X-rays interact with materials, they are able to:

[ "Cause substances to fluoresce.", "Remove an electron from an atom.", "Cause chemical changes that may lead to cells disfunctions." ]

0

A

Which of the following molecules are typical tracers for SPECT?

[ "F-18", "O-15", "99m-Tc", "Tl-201", "C-11" ]

2

C

Let's consider two systems of particles (with different gyromagnetic ratio) of spin ½ in a magnetic field \(\vec B_0\). The total population as well as temperature in each system are the same. According to Boltzmann distribution :

[ "The system with highest \\( \\gamma \\) has more down spins than the system with lowest \\( \\gamma \\).", "The system with highest \\( \\gamma \\) has less down spins than the system with lowest \\( \\gamma \\).", "The distribution is exactly the same : it does not depend on \\(\\gamma\\)." ]

1

B

NMR stands for

[ "Nuclear Moment of Resonance", "Non Magnetic Radiation", "Nuclear Magnetic Radiation", "Nuclear Magnetic Resonance" ]

3

D

>>In spin echo sequences, what do TR and TE refer to?

[ "TR: the spacing between successive 90-degree pulses; TE: time between the 90-degree pulse and the spin echo", "TR: the spacing between successive 90-degree pulses; TE: the spacing between the 90-degree pulse and the 180-degree pulse", "TR: time before the 90-degree pulse and the spin echo; TE: the spacing between successive 90-degree pulses", "TR: the spacing between the 90-degree pulse and the 180-degree pulse; TE: the spacing between successive 90-degree pulses" ]

0

A

What can improve SNR in MRI if it is increased?

[ "Bandwidth", "Gradient strength", "Acquisition time" ]

2

C

In FDG PET, how is called the factor that takes into account that what one is measuring with deoxyglucose is not the real glucose molecule but an analog of glucose?

[ "The Lumped constant", "The Fick constant" ]

0

A

What is the duration of a 1H 90° pulse when B1 = 1.00 mT?

[ "4.12 microseconds", "5.87 microseconds", "9.82 microseconds", "12.45 microseconds" ]

1

B

In diagnostic X-ray systems, filters are used to "harden" the beam. This process is mainly due to:

[ "Coherent scattering.", "Photoelectric effect.", "Compton effect.", "Pair production." ]

1

B

What is the form of the majority of energy produced by electrons in X-rays tubes?

[ "Light", "Sound", "X-ray energy", "Heat" ]

3

D

Which MR imaging parameter determines how much of T1 (longitudinal) recovery occur?

[ "TR", "TE", "Bandwidth (BW)", "Number of excitations", "Gradient intensity" ]

0

A

Let's consider two media: the speed of sound in the two media is different and impedances of these two media are identical. A sound pulse reaches the boundary between these two media with normal incidence. Does the reflection occur?

[ "Yes", "No" ]

1

B

Which of the following imaging modalities is/are ionizing?

[ "X-rays", "CT (Computed tomography)", "MRI (Magnetic resonance imaging)", "US (Ultrasounds)", "PET (Positron emission tomography)", "SPECT (Single photon emission computed tomography)" ]

0

A

What is true concerning scatter radiation?

[ "They reduce contrast resolution", "They contribute to the image formation." ]

0

A

Where does the annihilation of positron and electron take place?

[ "In the radionuclide emitting the positron", "At a short distance from the radionuclide" ]

1

B

How does the particular dendritic conductance of CA1 pyramidal neurons influence the integration of the signals from two synapses, one close to the soma and one close to the distal dendrite, activated with a time delay?

[ "Both signals are integrated to generate an AP in the soma if the delay is short (up to 20 ms) and the distal synapse is activated first or very shortly after the proximal one", "Both signals are integrated to generate an AP in the soma even when the delay is long (up to 50 ms)", "Each of the two signals generate a separate AP in the soma except when the time delay is very short (less than 10 ms), in which case a single AP is generated", "Both signals are integrated to generate an AP in the soma if the delay is short (up to 20 ms) and the proximal synapse is activated first or very shortly after the distal one" ]

0

A

A neuron can be considered as a dipole. Why does the amplitude of the extracellular potential fall proportionally to the square of the distance from the dipole it originates in?

[ "Because the current is divided by the square of the distance to obtain the extracellular potential in the formula", "Because as one moves further away from the dipole, current and return current cancel each other out more and more in addition to the decrease in amplitude that is proportional to the distance", "Because the sum of all currents acting on an extracellular location is weighted by a multiple of the squared distance between compartment and the extracellular location", "It does not fall proportionally to the square of the distance, but proportionally to the distance between the dipole and the extracellular location" ]

1

B

Which method can be used to link a broad range of different time and spatial scales when studying the brain?

[ "Patch clamp", "PET imaging", "Modeling and simulation", "Long-term clinical studies" ]

2

C

How are different regions of the hippocampus connected to each other?

[ "The connections are largely reciprocal; if region A projects to region B, region B also projects to region A", "The connections are mainly unidirectional along a stream", "The connections allow signals to spread along the longitudinal axis of the hippocampus", "The connections keep the signals mainly in one slide of the longitudinal axis called a lamella" ]

1

B

What are fixed point attractors in nonlinear recurrent networks?

[ "Specific neurons that are always activated", "Stable patterns of activity towards which other patterns converge", "Memory traces, if the can be learned by the network", "Connections between neurons that get consolidated upon recall" ]

1

B

What are the two main ions contributing to the generation of an action potential?

[ "Na+ and Cl-", "Ca2+ and Cl-", "H+ and K+", "Na+ and K+" ]

3

D

Which important point must be considered when populating the region to model?

[ "The types of cells present in the region", "The shape of the volume to populate", "The density of each cell type", "The location and orientation of the cells in the volume" ]

0

A

What determines the firing pattern of a neuron in response to step current injections?

[ "The length of its axon", "Its expression of different voltage-gated ion channels", "Which neurotransmitter it expresses", "The post-synaptic domain of the cells that it targets" ]

1

B

What does simulating a neuron help to understand?

[ "Dendritic integration", "The neural code", "The role of the biophysical make-up of a neuron", "Potentially all of the above, depending on the type of model used" ]

3

D

Which statement about CA1 pyramidal neurons are true?

[ "The KA density increases with the distance to the soma, the Ih density stays constant", "The density of both K and non-specific ion channels increases when the distance to the soma increases", "They receive two main independent inputs, one from the entorhinal cortex and one from the olfactory bulb that arrive at different locations", "They receive two main inputs that both originate from the same signal in the entorhinal cortex and arrive at different locations with a time delay" ]

1

B

Which property of the hippocampus makes it a good model to study the nervous system?

[ "The connections on the hippocampus are almost unidirectional", "The synapses are highly plastic", "Hippocampal neurons can be grown in culture", "All of the above" ]

3

D

What is true about gamma and theta oscillations?

[ "Theta oscillations are persistent, while gamma oscillations are transient", "Both types of oscillations can be transient or persistent", "The same receptors can activate or block a type of oscillations", "Different receptors activate or block each type of oscillations", "Not all types of oscillations can be observed in all hippocampal regions", "Gamma oscillations can have a broad range of high frequencies" ]

1

B

>>The factors listed below influence either presynaptic or postsynaptic specificity. Which ones affect postsynaptic specificity?

[ "The dynamic release properties", "The number of receptors", "Postsynaptic properties", "The release probability", "The type of receptors", "The number of release sites" ]

1

B

How are somatic and dendritic conductances related to the firing pattern of a cell?

[ "Each cell type has a fixed firing pattern that results from all individual cells of the same type having the same somatic and dendritic conductances", "Each combination of conductances generate a different firing behavior", "Specific conductances must be at certain levels in order to generating a defined firing pattern", "Several combinations of conductances are able to reproduce the same firing behavior" ]

2

C

How does the calculation of extracellular potentials help with experimental design?

[ "Mismatches between simulations and experimental data highlight mistakes in experimental data and show how experiments need to be modified in order to match the model", "It doesn’t help experimental design, but generates data so that experiments are not necessary anymore in order to answer biological questions", "Because the calculation of extracellular potentials allows separating the contribution of each neuron to the signal, it can inform on where to place electrodes to measure specific activities", "All of the above" ]

2

C

What do the simple networks explaining gamma oscillations and ripples not have in common?

[ "The same connectivity pattern", "A high number of basket cells", "Direct auto-inhibitory feedback loops acting on single basket cells", "All of the above" ]

3

D

Which statement concerning the firing pattern of neurons is true?

[ "There is a correlation between the firing pattern and the calcium binding protein content.", "There is an absolute correlation between the firing pattern and the calcium binding protein content of all interneurons.", "All fast-spiking cells express the potassium channel Kv3.1", "Basket cells are the only fast spiking cells in the hippocampu" ]

0

A

What is the effect of the particular dendritic conductance of CA1 pyramidal neurons on back-propagating APs?

[ "AP amplitude along the dendrites increases as the distance to the soma increases", "AP amplitude along the dendrites decreases as the distance to the soma increases", "AP amplitude stays constant along the dendrites over the distance to the soma", "AP amplitude along the axon decreases as the distance to the soma increases" ]

1

B

How can modeling help with sparse data?

[ "By identifying principles allowing to predict missing data", "By guiding experimental design in highlighting missing data", "By finding connections between data types and data points allowing interpolation of missing data", "All of the above" ]

3

D

When do the synapses in CA3 need to be plastic?

[ "For pattern separation", "For memory retrieval", "For learning", "All of the above" ]

2

C

Which statement about hippocampal synaptic plasticity, network oscillations and neuromodulation is true?

[ "Network oscillations in the hippocampus endow it with cognitive functions like learning and memory", "Neuromodulation in the hippocampus gate synaptic plasticity and enhance network oscillations", "The oscillations observed in the hippocampus are similar to those observed in other parts of the cortex", "All of the above" ]

3

D

Which statements about cable theory are true?

[ "The conductance for each ion stays the same all along the axon and dendrites", "It quantifies the propagation of a signal along the axon and dendrites", "The change in voltage over the distance is related to the change in voltage over time", "The neuron is discretized to form several coupled compartments corresponding to parts of the axon and dendrites" ]

1

B

Why is a massive increase in model complexity a challenge?

[ "Because computational capacity has not increased enough during the last century", "Because existing scientific codes like NEURON are not adapted to use massively parallel systems", "Because neuron networks cannot be simulated using parallel systems", "It is not a challenge; very large models can be simulated on normal desktop computers since desktop computers have become much faster and have large storage capabilities" ]

1

B