MRI Quiz

What does the term "spin-lattice relaxation time" (T1) represent in MRI?

• The time constant for spins to lose coherence due to magnetic field inhomogeneities

• The time constant for spins to regain longitudinal magnetization

• The time constant for spins to achieve transverse magnetization

• The time constant for spins to lose coherence due to spin-spin interactions

Which of the following is a characteristic property of T2 relaxation time in MRI?

• It is shorter than T2 relaxation time

• It is influenced by magnetic field inhomogeneities

• It represents the time constant for spins to return to equilibrium

• It is not affected by the presence of paramagnetic substances

In MRI, what is the role of the radiofrequency (RF) coil during imaging?

• It creates the main magnetic field

• It receives the MR signal from the patient

• It amplifies the MR signal before detection

• It enhances spatial resolution of the images

Which MRI sequence is typically used for imaging T2-weighted images?

• Gradient echo (GRE)

• Inversion recovery (IR)

• Spin echo (SE)

• Echo-planar imaging (EPI)

What is the purpose of applying a slice-selective RF pulse in MRI?

To excite spins within a specific slice

• To excite spins within a specific slice

• To refocus spins after dephasing

• To dephase spins for T2-weighted imaging

• To reduce T1 relaxation times

Which of the following imaging artifacts is caused by magnetic field inhomogeneities in MRI?

• Chemical shift artifact

• Aliasing artifact

• Zipper artifact

• Flow artifact

What physical parameter is primarily responsible for the difference in signal intensity between fat and water in MRI?

• Proton density

• T1 relaxation time

• T2 relaxation time

• Chemical shift

In MRI, what is the purpose of using gradient magnetic fields during imaging?

• To create spatial encoding of the MR signal

• To enhance contrast in T1-weighted images

• To refocus the MR signal after excitation

• To amplify the MR signal

What does the term "echo time" (TE) refer to in MRI sequences?