quiz 5 Flashcards
What best describes Temporal resolution?
Ability to distinguish structural differences over time
If you increase the TR parameter what happens to your SNR.
Increases SNR while increasing scan time
Increasing your TE has what affect on your SNR?
Decreases SNR however will increase T2 weighting improving contrast
When increasing FOV what happens to signal to noise?
Increases
Which would have an increase in SNR, a large or small pixel?
Large
If you increase the receive bandwidth what affect will this have on SNR?
Decrease
Would a large or small surface coil provide better SNR.
small
Which provides better spatial resolution a square or rectangular pixel?
square
If you use a rectangular FOV to fit the anatomy but the Pixel remains square does this have a noticeable change in spatial resolution.
no
If you use a rectangular FOV to fit the anatomy but the Pixel remains square what affect will this have on scan time?
decrease
A broad receive bandwidth will contain more noise than a narrow bandwidth.
true/false
True
The best way to improve SNR is by increasing your NSA (NEX)
true/false
false
Flip angles less than 90 degrees offer a larger amount of transverse magnetization thus increasing signal amplitude(max siganal).
true/false
false
To determine voxel volume you need the pixel dimensions and the slice thickness to determine volume.
true/false
atrue
Increasing slice thickness from 5mm to 10mm with increase SNR
true/false
true
The signal to noise ratio is….
The ratio of the amplitude of the received to the average amplitude of noise
Which would have a greater SNR.
a pixel dimension of 10mm x 10mm with 8mm slice thickness
The parameter allows us to saturate bound Protons to increase signal in the free protons.
MTC
This is responsible for determining the amount of T2 weighting.
TE
The two parameters are responsible for the amount of T1 and PD weighting.
TR
Flip Angle
PD in the tissues being imaged determines the amplitude of signal received.
true/false
true
Would Lung tissue or tissues in the pelvis have a higher amplitude of proton density?
pelvis
Coil selection and placement play a role in both SNR and CNR.
true/false
true
An image of the liver that has high CNR but low SNR is of little or no diagnostic value
true/false
false
An image with a rectangular FOV and rectangular pixels would have the same spatial resolution as an image with the same rectangular FOV and
true/false
false
