MRI contrast

What is the primary advantage of MRI compared to other imaging modalities?

• Speed of imaging

• Cost-effectiveness

• Excellent soft tissue discrimination

• Simplicity of use

What are intrinsic contrast parameters in MRI?

• Parameters that can be adjusted by the operator

• Parameters inherent to the body’s tissues

• Settings selected on the MRI machine

• External factors influencing imaging

Which of the following is NOT an intrinsic contrast parameter?

• T1 recovery time

• Proton density

• Flip angle

• Apparent diffusion coefficient (ADC)

Extrinsic contrast parameters include all of the following EXCEPT:

• TR (Repetition Time)

• TE (Echo Time)

• Proton density

• b value

What determines if a tissue returns a high or low signal in an MR image?

• The size of the tissue

• The angle of incidence of the MRI beam

• The transverse component of coherent magnetization at time TE

• The tissue’s proximity to the MRI coil

What does T1 relaxation time refer to?

• The time it takes for 63% of transverse magnetization to be lost

• The time it takes for 63% of longitudinal magnetization to be regained

• The duration of the MRI scan

• The interval between two successive pulses

How do fat and water differ in their T1 recovery times?

• Fat has a longer T1 time because of its molecular structure

• Water has a shorter T1 time due to its high inherent energy

• Fat recovers more rapidly along the longitudinal axis than water

• Water recovers more rapidly than fat due to its molecular mobility

Which type of image uses a short TR and short TE?

• T1 weighted image

• T2 weighted image

• Proton density weighted image

• Diffusion weighted image

In a T2 weighted image, which would appear brighter?

• Fat

• Cerebrospinal fluid (CSF)

• Muscle

• Bone

What is the significance of T2 decay in MRI?

• It represents the decay of free induction decay following the RF excitation pulse

• It is slower than T2 decay

• It is unaffected by magnetic field inhomogeneities

• It occurs before T1 recovery