MRI In Practice: Chapter 2 Image Weighting and Contrast Flashcards
Which of the following is not an intrinsic contrast parameter?
a. T1 recovery time
b. flow
c. T2 recovery time
d. TE
d. TE
Intrinsic contrast parameters can not be changed
Which of the following is not an extrinsic contrast parameter?
a. TR
b. apparent diffusion coefficient (ADC)
c. b value
d. flip angle
b. apparent diffusion coefficient (ADC)
Extrinsic contrast parameters can be changed by the technologist
T1 and T2 relaxation depends on:
a. the inherent energy of the tissue
b. how closely packed the molecules are
c. how well the molecular tumbling rate matches the larmor frequency of hydrogen.
d. all of the above
d. all of the above
T1 relaxation and T2 decay represent the time it takes for ___ % of the total magnetization to be regained in the longitudinal plane via spin lattice energy transfer (T1), or lost in the transverse plane via spin – spin interactions (T2).
a. 37%
b. 63%
c. 42.57%
d. 63.86%
b. 63%
The T1 time of fat is _____ and the T1 time of water is ______.
a. short, short
b. short, long
c. long, short
d. long, long
b. short, long
The T2 time of fat is _____ and the T2 time for water is _____.
a. short, short
b. short, long
c. long, short
d. long, long
b. short, long
On a T1 contrast image how does fat appear? How does water appear?
a. bright, bright
b. bright, dark
c. dark, dark
d. dark, bright
b. bright, dark
On a T2 contrast image how does fat appear? How does water appear?
a. bright, bright
b. bright, dark
c. dark, dark
d. dark, bright
d. dark, bright
Proton density weighted images are weighted by looking at
a. areas of high proton density and low proton density
b. areas of high T1 values and low T1 values
c. areas of low T2 values and low T1 values
d. dense proton clusters present
a. areas of high proton density and low proton density
For a T1 weighted image you want a
a. long TR, short TE
b. long TR, long TE
c. short TR, short TE
d. short TR, long TE
b. Long TR, short TE
In order to rephase magnetic moments
a. a 180° rephasing pulse is applied
b. a gradient is applied
c. either a or b
d. None of the above
c. either a 180 pulse is applied or gradient is used
What is TAU time
a. 1/2 TE
b. 1/2 TR
c. 2 TE
d. 2 TR
TAU is the time taken to de-phase after the 90° pulse is withdrawn and is equal to 1/2 TE
For Proton density weighted images how to high PD structures appear? How do low PD structures appear?
a. bright, dark
b. dark, dark
c. bright, bright
d. dark, dark
a. bright, dark
As field strength increases tissues take
a. The same amount of time to relax
b. a shorter time to relax
c. a longer time to relax
d. No time to relax
a. a longer time to relax
To produce a high signal in which plane must there be a large component of coherent magnetization?
a. lateral plane
b. longitudinal plane
c. transverse plane
d. ipsilateral plane
c. transverse plane
