Neuroimaging Flashcards
Page 55 onwards
What is the primary requirement for recording the MR signal?
a. Receiving coil tuned to a different RF frequency
b. Measure gravitational field decay
c. Apply a strong magnetic field
d. Receiving coil tuned to the same RF frequency as the exciter coil
d. Receiving coil tuned to the same RF frequency as the exciter coil
In T2 relaxation, what causes the decay of transverse magnetization?
a. Flipped nuclei realigning with the magnetic field
b. Loss of coherence in spinning
c. Disturbances in the magnetic field
d. Net magnetization precession
b. Loss of coherence in spinning
What is K-space in MRI?
a. A matrix storing raw data
b. Total magnetization vector
c. Resonance frequency
d. Gradient of magnetic field
a. A matrix storing raw data
How is spatial resolution achieved in MRI?
a. Using strong radiofrequency pulses
b. Applying a gradient of magnetic field
c. Increasing the number of nuclei
d. Decreasing the voxel size
b. Applying a gradient of magnetic field
What technique allows simultaneous imaging of multiple slices along the z-axis?
a. Echo Planar Imaging
b. Fourier Transform
c. MultiBand imaging
d. Slice selection
c. MultiBand imaging
Which MRI sequence is used to create images with different contrasts?
a. T1-weighted
b. T2-weighted
c. GRE
d. SWI
a. T1-weighted
How is T2* relaxation affected by inhomogeneities in the magnetic field?
a. It increases T2* relaxation
b. It decreases T2* relaxation
c. It has no effect on T2* relaxation
d. It reverses T2* relaxation
a. It increases T2* relaxation
What is the basis for functional MR imaging?
a. T1 relaxation
b. T2 relaxation
c. T2* relaxation
d. Spin coherence
c. T2* relaxation
What is the main determinant of image contrast in gradient echo sequences?
a. T1 relaxation
b. T2 relaxation
c. T2* relaxation
d. Spin coherence
c. T2* relaxation
What does EPI stand for in MRI?
a. Extended Pulse Imaging
b. Echo Planar Imaging
c. Enhanced Phase Inversion
d. Efficient Proton Interactions
b. Echo Planar Imaging
How does fMRI differ from EEG and MEG in terms of spatial and temporal resolution?
a. Higher spatial, higher temporal
b. Lower spatial, higher temporal
c. Higher spatial, lower temporal
d. Lower spatial, lower temporal
c. Higher spatial, lower temporal
What does BOLD contrast measure in fMRI?
a. Blood flow
b. Oxygen consumption
c. Oxygenation level
d. Blood volume
c. Oxygenation level
What is neurovascular coupling?
a. Connection between neurons and blood vessels
b. Relationship between local neural activity and changes in cerebral blood flow
c. Mechanism of blood clotting in the brain
d. Formation of new blood vessels in the nervous system
b. Relationship between local neural activity and changes in cerebral blood flow
Why does the brain require a constant supply of glucose and oxygen?
a. To maintain a high-energy state
b. To store energy
c. To produce ATP through anaerobic metabolism
d. To supply energy for intrinsic activity
d. To supply energy for intrinsic activity
What is the primary energy currency for cells in the human body?
a. Glucose
b. Oxygen
c. ATP
d. ADP
c. ATP
How is energy produced in the brain through ATP?
a. By breaking down glucose
b. By breaking down oxygen
c. By breaking down ADP
d. By breaking down water
a. By breaking down glucose
Which arteries form the Willis circle in the brain?
a. Anterior Cerebral Artery (ACA)
b. Middle Cerebral Artery (MCA)
c. Posterior Cerebral Artery (PCA)
d. All of the above
d. All of the above
What does the initial dip in HRF represent?
a. Decrease in blood flow
b. Increase in oxygen consumption
c. Increase in blood volume
d. Decrease in deoxyhemoglobin
b. Increase in oxygen consumption
According to the Balloon model, what happens during neuronal activation?
a. Blood flow into the venous system decreases
b. Venous system expands like a balloon
c. Blood volume decreases in active regions
d. Neuronal activity is suppressed
b. Venous system expands like a balloon
What is the controversial aspect of the Astrocyte-neuron lactate shuttle model?
a. It contradicts the principles of fMRI
b. It challenges the role of astrocytes in energy supply
c. It suggests lactate negatively affects neurons
d. It claims the BOLD response reflects astrocyte activation
d. It claims the BOLD response reflects astrocyte activation
How does the magnitude of the static field impact BOLD signal changes?
a. Higher field strength decreases signal changes
b. Lower field strength increases signal changes
c. Field strength has no impact on signal changes
d. Higher field strength increases signal changes
d. Higher field strength increases signal changes
What is the purpose of choosing a balanced TE in MRI sequences?
a. To increase T1 relaxation
b. To minimize T2 relaxation effects
c. To enhance T2* relaxation
d. To shorten TR
b. To minimize T2 relaxation effects
How does DTI visualize white matter tracts?
a. By measuring blood flow
b. By measuring water diffusion
c. By measuring glucose metabolism
d. By measuring neural activity
b. By measuring water diffusion
What does FA represent in DTI?
a. Fractional Anisotropy
b. Functional Activation
c. Fiber Accumulation
d. Fornix Assessment
a. Fractional Anisotropy