The Cubic Shaped Voxel and The Slice Select Gradient Question

1.)Which of the following statement is/are TRUE?

A long TR increases SNR

A short TE increases SNR

A shorter flip angle decreases SNR

2. 

An isotropic voxel refers to a:circular shaped voxelcubic shaped voxelrectangular shaped voxeltriangular shaped voxel
3.) QUESTION 3

Which of the following would achieve the highest SNR for a given sequence?using a Gradient Echo pulse sequenceusing a fine matrixusing thick slicesusing the smallest FOV possible

a diagram of a gating procedurea Fourier transformationa pulse sequencethe Larmour equation
QUESTION 5

pixel sizevoxel sizesignal to noise ratiocontrast to noise ratio

QUESTION 6

slice select gradientphase encode gradientfrequency ecode gradientreadout gradient

QUESTION 7

large volumes of datamultiplanar reconstructionvariable sized sliceshigh resolution

QUESTION 8

without increasing scan time is to:increase slice thicknessincrease the number of signal averagesdecrease the voxel sizeincrease the number of slices

QUESTION 9

T1T2T2*PRoton Density (PD)

QUESTION 10

is considered false about a coarse matrix.

A course matrix contains a large number of voxelsA coarse matrix has a low number of frequency and phase encode steps

A course matrix increases the signal to noise SNR relative to a fine matrix

All of the above answers are false

QUESTION 11

Decreasing the FOV will decrease the voxel volume size, which will decrease SNR.
True False

QUESTION 12

lDoubling the number of signal averages (NSA, NEX, AQS) will double the SNR

True False

QUESTION 13

A Short Tau Inversion Recovery (STIR) is an ideal sequence for post contrast (GBCA) imaging. True False

QUESTION 14

GRE sequences have more signal than spin echo or fast spin echo sequences becuase GRE sequences convert all of the longitudinal magnetization into the transverse plane.
True False

QUESTION 15

List 2 ways to improve spatial resolution

QUESTION 16

According to Westbrook (p.234 – 235) what are two advantages of using rectangular field of view (recFOV)?

QUESTION 17

What is a volume image?How is volume imaging achieved?How does voxel dimensions affect image resolution?

QUESTION 18

What is a 3D volumetric aquisition?What are the advantages of volumetric imagingWhat is slice encoding?Westbrook, p. 207 – 208