Week 9 Flashcards

1
Q

what is STIR used for

A

fat suppression

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what is CSF used for

A

fluid suppression

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

applications of spin-echo are __

A

any part of body except fast moving organs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

applications of inversion recovery are __

A
  • CNS (FLAIR)
  • MSK (STIR)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

applications of gradient-echo are __

A

fast imaging

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

advantages of spin-echo are __

A
  • good image quality
  • gold standard for image contrast & weighting
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

advantages of inversion recovery are __

A
  • good image quality
  • sensitive to pathology
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

advantages of gradient-echo are __

A
  • short scan time
  • improved SNR by more NEX
  • sensitive to susceptibility
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

disadvantages of spin-echo are __

A
  • long scan times
  • motion artifacts
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

disadvantages of inversion recovery are __

A
  • very long scan time
  • motion artifacts
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

disadvantages of gradient-echo are __

A
  • B0 inhomogeneity & susceptibility
  • blooming artifacts
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

challenges of MRI abdomen

A
  • Respiratory motion
  • Organ location
  • Peristalsis
  • Artery pulsing
  • Patient’s cooperativeness
  • Breath hold time (10 – 20 s)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

MRI abdomen patient position

A
  • Headfirst supine
  • Fasting 6 – 8 hours to distend gallbladder
  • Breath hold instructions
  • Power injector if dynamic scan is neeeded using 20 IV cannula
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

different methods to test arrival of MR contrast agent

A
  • test bolus timing
  • fluoroscopic trigger
  • time resolved imaging
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what is the disadvantage of fluoroscopic trigger

A

operator dependent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

MRI abdomen axial range is __

A

diaphragm till iliac crest

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

MRI abdomen axial range for 3D pre & post contrast are __

A

diaphragm till lower poles of kidney

18
Q

MRI abdomen coronal range is __

A

diaphragm till iliac crest

19
Q

MRI abdomen 3D VIBE + C + BH coronal range is __

A

anterior liver through posterior kidney

20
Q

what are fast spin echoes

A

multiple echoes in 1 TR where middle of K-spaces filled up first before filling up peripheries

21
Q

In HASTE, all data from all K-spaces are obtained after __

A

single 90 degrees excitation pulse

22
Q

HASTE creates __

A

mirror image

23
Q

How does HASTE work

A

Uses multiple 180° pulse echoes with shortened interecho spacing to acquire all imaging data during TR

24
Q

phase cycling formula

A

phase cycling = 1 / frequency offset

25
False vs True pelvis
False pelvis (whole pelvis) vs true pelvis (prostate, uterus, ovaries)
26
increasing bandwidth will __ blurriness by ___
decrease; reducing echo spacing to allow more quickly acquired data but higher fat signal
27
high receiver bandwidth advantages are __
- less chemical shift, metal / distortion / susceptibility artifacts - shorter minimum TE/TR & echo spacing
28
high receiver bandwidth disadvantages are __
lower SNR, large FOV, more noise
29
MRI pelvis patient position
- Supine headfirst / feet first - Posterior spine coil + anterior body / torso - Superior edge of coil above iliac crest - Female pelvis = 20G cannula, prostate dynamic = 18G cannula - Empty bowels before imaging
30
MRI pelvis sagittal slice covers __
- entire pelvis from right to left acetabulum - parallel to lumbosacral spine
31
what is the best plane to visualize uterus
MRI pelvis sagittal
32
MRI pelvis axial slice covers __
- position block perpendicular to endometrium - slice covers entire uterus & ovaries
33
MRI pelvis coronal slice covers __
- position block parallel to endometrium - slice covers entire uterus & ovaries
34
what pelvis is used to visualize pelvic organs
true pelvis
35
what pelvis is used for lymph node screening
false pelvis
36
what are the challenges of MRI pelvis
- Pelvis less sensitive to respiratory motion except upper pelvis - Heterogenous region due to vessels / organs / bowel content / peristalsis
37
MRI rectum sagittal view covers __
position block parallel to interpubic cartilage & anal canal
38
MRI rectum axial view covers __
- position block parallel to right & left hip joints - range = iliac crest to 1 inch below SP
39
MRI rectum axial oblique view covers __
position block perpendicular to rectum / any visible cancer
40
MRI rectum coronal oblique view covers __
- position block parallel to rectum & angled till horizontally across rectal cancer / parallel to right & left hip joint - Slices cover entire rectum & pre-sacral space from SP to sacrum