Physics 2 Quiz 1.2

Question 1

As velocity of flow increases, the time of flight effect:

Accepted Answer

Increases

Answer

Reverses

Answer

Decreases

Answer

Stays the same

Question 2

Gradient moment nulling predominantly increases intra-voxel dephasing?

Accepted Answer

False

Answer

True

Question 3

Entry slice phenomenon (inflow effect) is most prominent in ______slice of "stack" of slices.

Accepted Answer

First

Answer

Last

Answer

Second

Answer

Middle

Question 4

Turbulent flow is flow at different velocities that fluctuates randomly?

Accepted Answer

True

Answer

False

Question 5

The causes of flow artifacts are known as flow phenomena. The principle phenomena are all of the following except:

Accepted Answer

Exta-voxel dephasing

Answer

Entry slice phenomenon

Answer

Time of flight

Answer

Intra-voxel dephasing

Question 6

As TE increases, a higher proportion of flowing nuclei have _____ the slice between the excitation pulse and rephasing pulse.

Accepted Answer

Exited

Answer

Stayed the same between

Answer

None of these

Answer

Entered

Question 7

A method in which the specific frequency of just fat, or water, is transmitted to push just those protons into transverse magnetization prior to the 90 degree RF pulse is known as what?

Accepted Answer

Chemical Presaturation

Answer

Presaturation Band

Answer

Spatial Presaturation

Question 8

Fat or water saturation is most effective on _______field systems.

Accepted Answer

High

Answer

Low

Answer

None of these

Answer

Mid

Question 9

Entry slice phenomenon _________if nuclei receive repeated excitations.

Accepted Answer

Decreases

Answer

None of these

Answer

Increases

Answer

Stays the same

Question 10

Spatial pre-saturation nullifies the signal from flowing nuclei so the effects of entry slice and time of flight phenomena are minimized

Accepted Answer

True

Answer

False

Question 11

Flow related enhancement increases as the: (select all that apply)

Accepted Answer

TE decrease

Accepted Answer

Velocity of flow decreases

Accepted Answer

Slice thickness increases

Answer

Velocity of flow increase

Answer

TE increases

Answer

Slice thickness decreases

Question 12

All of the following affect entry slice phenomenon except:

Accepted Answer

Phase Matrix

Answer

TR

Answer

Slice Thickness

Answer

Direction of flow

Answer

Velocity of flow

Question 13

Vortex flow is flow that is initially laminar but then passes through a stricture of stenosis in the vessel?

Accepted Answer

True

Answer

False

Question 14

To saturate or null fat or water, the precessional difference between the two must be sufficiently _______ so that they can be isolated from each other.

Accepted Answer

Large

Answer

Medium

Answer

Small

Answer

None of these

Question 15

Second order motion can be compensated for as system can only correct for flow that is at constant velocity and direction during data acquisition.

Accepted Answer

False

Answer

True

Question 16

Time of flight effects depend of the following: (Select all that apply)

Accepted Answer

Velocity of flow

Accepted Answer

Slice thickness

Accepted Answer

TE

Answer

Flip angle

Answer

Matrix

Question 17

The four principal types of flow are all of the following except:

Accepted Answer

Circular flow

Answer

Vortex flow

Answer

Turbulent flow

Answer

Spiral flow

Answer

Laminar flow

Question 18

In what orientation and position, should a saturation region be located in order to eliminate carotid flow from transverse images of the cervical spine?

Accepted Answer

Transverse, inferior to the region of interest

Answer

Transverse, superior to the region of interest

Answer

Coronally, anterior to the spine

Answer

Coronally. posterior to the spine

Question 19

For flowing nuclei, to produce a signal, nucleus must receive a 90 degree (excitation) and a 180 degree (rephasing) pulse. This is known as?

Accepted Answer

Time of flight phenomena

Answer

Dark Blood Technique

Answer

High velocity signal loss

Answer

Entry slice phenomena

Question 20

Counter-current flow has flowing nuclei traveling in _______ direction to slice excitation.

Accepted Answer

Opposite

Answer

None of these

Answer

Same

Answer

Both