Part C: Special procedures Flashcards
1
Q
- Normal blood flow (demonstrated by a parabolic blood flow profile) is known as:
a. Laminar flow
b. Accelerated flow
c. Vortex flow
d. Turbulent flow
A
a. Laminar flow
2
Q
- Blood flow at the area of stenosis (vascular narrowing) is known as:
a. Laminar flow
b. Accelerated flow
c. Vortex flow
d. Turbulent flow
A
b. Accelerated flow
3
Q
- The swirling blood flow that occurs just past the area of a stenosis is known as:
a. Laminar flow
b. Accelerated flow
c. Vortex flow
d. Turbulent flow
A
c. Vortex flow
4
Q
- Normal blood flow is known as:
a. Laminar flow
b. Accelerated flow
c. Vortex flow
d. Turbulent flow
A
d. Turbulent flow
5
Q
- A major advantage of MRA over conventional angiography is that:
a. Images with both heavy T1 and T2 weighting can be produced
b. Multiple views can be produced from a single acquisition
c. Much smaller catheters are used
d. Less ionising radiation is used
A
b. Multiple views can be produced from a single acquisition
6
Q
- The MRA sequence that is leas sensitive to slow flow is:
a. 3D phase contrast MRA (PC MRA)
b. 3D time of flight (TOF)
c. 2D PC
d. 2D TOF
A
b. 3D time of flight (TOF)
7
Q
- The MRA sequence that is most sensitive to smaller vessels is:
a. 3D phase contrast MRA (PC MRA)
b. 3D time of flight (TOF)
c. 2D PC
d. 2D TOF
A
b. 3D time of flight (TOF)
8
Q
- The MRA sequence that is sensitive to flow direction is:
a. 3D phase contrast MRA (PC MRA)
b. 3D time of flight (TOF)
c. 2D TOF
d. Multislice vascular
A
a. 3D phase contrast MRA (PC MRA)
9
Q
- The MRA sequence that can be made sensitive to any flow velocity is:
a. 3D phase contrast MRA (PC MRA)
b. 3D time of flight (TOF)
c. 2D TOF
d. Multislice vascular
A
a. 3D phase contrast MRA (PC MRA)
10
Q
- The signal intensity on TOF MRA sequences is related to:
a. Gadolinium
b. Flow-related enhancement
c. Velocity- induced phase shift
d. Restricted diffusion
A
b. Flow-related enhancement
11
Q
- The signal intensity on PC MRA sequences is related to:
a. Gadolinium
b. Flow-related enhancement
c. Velocity- induced phase shift
d. Restricted diffusion
A
c. Velocity- induced phase shift
12
Q
- The signal intensity on diffusion sequences is related to:
a. Gadolinium
b. Flow-related enhancement
c. Velocity- induced phase shift
d. Amount of diffusion
A
d. Amount of diffusion
13
Q
- The removal of signal from vessels is an MRA sequence is achieved by:
a. Gradient moment nulling
b. Spatial presaturation
c. Spectral presaturation
d. a and b
A
b. Spatial presaturation
14
Q
- The following is (are) important in MRA sequences to minimise the loss of signal due to dephasing within a voxel:
a. Long TR
b. Small voxels
c. Short TE
d. b and c
A
d. b and c
15
Q
- Blood flow velocities are greatest:
a. Further away from the heart
b. At a vessel wall
c. At the center of a vessel
d. In a 3D time of flight sequence
A
c. At the center of a vessel