Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Radiology > MRI > Flashcards

MRI Flashcards

1
Q

Basic principles include all of the following except:

1) uses high magnetic field & radio frequency pulses
2) Uses ionizing radiation
3) multi planar images take longer
4) has good contrast resolution
5) may use IV contrast (i.e: gadolinium)
6) will take 30-60 min

A

2) does NOT use ionizing radiation

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

(T/F) the magnet is always on in an MRI

A

TRUE

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

What objects are considered projectile hazards “missile effect”?

A
  • oxygen cylinders
  • fire extinguishers
  • monitoring equipment
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

(SQ) hx of foreign body?

A
  • orbital trauma
  • plain radios
  • anatomic position relative to sensitive structures
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

(SQ) hx of implant/device, issues?

A
  • displacement
  • heating
  • alteration of device operation
  • imaging artifacts
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

(T/F) for stents and filters that are nonmagnetic, its ok to scan now

A

true!

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

(T/F) Pacemakers and implantable defib. are CI to MRI

A

TRUE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is an absolute CI to MRI?

A

intracranial aneurysm clips; do plain films or CT’s

- titanium clips are ok tho

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

When in doubt if something is a CI, what should you do?

A

consult “list” or MRI department

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Which of the following is not generally safe for MRI?

1) surgical hemostasis clips/sutures
2) IUD
3) radioactive seed implants
4) ortho fixation hardware & joint replacements

A

NONE; all are generally safe

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

(T/F) you should remove all metallic objects except for hearing aids or drug patches before entering MRI

A

FALSE; remove everything & wear gown

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What can you do for pt if the have issue w/ noisy MRI?

A

give them ear plugs or headphones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What can you do for pt that has claustrophobia?

A

communicate w/ tech, sedatives, open MRI

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What can occur due to use of gadolinium in pts w/ renal disease and should be screened prior?

A

nephrogenic systemic fibrosis- widened tissue fibrosis that involves skin thickening, contractures, and immobility

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What occurs in the resting stage of MRI?

A

Resting state: Hydrogen nuclei (protons) behave like small magnets
Magnetization: Hydrogen nuclei align w/ the strong magnetic field
Excitation: RF pulses→ protons absorb energy and are deflected
Relaxation: Protons return to pre-excitation & emit energy (signal)

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

What occurs in the magnetization stage of MRI?

A

Resting state: Hydrogen nuclei (protons) behave like small magnets
Magnetization: Hydrogen nuclei align w/ the strong magnetic field
Excitation: RF pulses→ protons absorb energy and are deflected
Relaxation: Protons return to pre-excitation & emit energy (signal)

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

What occurs in the excitation stage of MRI?

A

Resting state: Hydrogen nuclei (protons) behave like small magnets
Magnetization: Hydrogen nuclei align w/ the strong magnetic field
Excitation: RF pulses→ protons absorb energy and are deflected
Relaxation: Protons return to pre-excitation & emit energy (signal)

18
Q

What occurs in the relaxation stage of MRI?

A

Resting state: Hydrogen nuclei (protons) behave like small magnets
Magnetization: Hydrogen nuclei align w/ the strong magnetic field
Excitation: RF pulses→ protons absorb energy and are deflected
Relaxation: Protons return to pre-excitation & emit energy (signal)

19
Q

MRI will detect the signal emitted and display what?

A

display the intensity of the signal coming from each point

20
Q

Difference b/w T1 recovery and T2 decay?

A

T1 recovery: rate at which protons re-align w/ the field

T2 decay: rate at which protons “de-phase” w/ each other

21
Q

Diff. b/w T1 weighted image and T2 weighted image?

A

T1 weighted image: Fluid is dark, hypo-intense, low signal

T2 weighted image: Fluid is bright, hyperintense, high signal

22
Q

What’s bright on T1 vs T2?

A

Bright on T1: Fat, blood, protein, contrast enhancement

Bright on T2: Fluid (CSF, Bile, Urine)

23
Q

What’s dark on a T1 and T2 image?

A

cortical bone, air, fibrous tissue

24
Q

Indications for MRI of liver?

A
  • lesion detection to screen for hepatocellular carcinoma in cirrhosis, chronic hepatitis
  • lesion characterization for focal liver lesion “problem solving”
25
Q

“multiple T2 hyperintense lesion” are an example of?

A

lesion detection- hepatocell. carcinoma

26
Q

i.e: “T1 weighted, post-contrast arterial phase diffuse enhancement (hypervascular)”
I.e: “Hemangioma (benign), delayed phase”

^ examples of?

A

lesion characterization of focal liver lesion

27
Q

Technique for MRI of liver:

A
  1. Pre-contrast
  2. Inject IV gadolinium
  3. Arterial phase
  4. Portal venous phase
  5. Delayed phase
28
Q

indication for MRI of female pelvis?

A

Indeterminate adnexal mass:
- fat, blood, dermoid endometrioma
OR
Uterine fibroids eval.

29
Q

An MRI of the Pelvis can help problem solve by giving info on..?

A
  • uterine vs ovarian
  • characterization
  • cystic or solid
  • tissue type
30
Q

What uses heavily T2 weighted sequences, fluid (bile) comes out very intense and uses multiplanar imaging for the abdomen/pelvis?

A

MRCP: magnetic resonance cholangiopancreatography

31
Q

Diff. b/w CT scan and MRI:

A 
CT Scan:
-Single breath hold
-Scan time: <30 sec
-Table time: < 5 min 
MRI: 
-multiple sequences 
-Table time: 30-45 min
32
Q

(T/F) An MRI of the chest has good sensitivity for calcium and can be used to image the lungs

A

FALSE; poor sensitivity and not used for lungs

33
Q

Which MRI can be used to see a lateral collateral ligament tear or marrow replacement/infiltration?

A

Musculoskeletal MRI

34
Q

Intra-axial enhancing mass/ edema and midline shift can be seen by ordering what?

A

MRI in neuroimaging

35
Q

(T/F) MRI can be used to see a herniated disc

A

TRUE

36
Q

what is first line for imaging of the breast?

A

mammography!! 2nd line is ultrasound

37
Q

3rd line for imaging of the breast and is used to evaluate implants, evaluate the extent of the disease, and for high risk pt screens?

A

MRI of the Breast

38
Q

Screening guidelines for MRI of the breast in women?

A
  • annual MRI starting at 25-30 for women w/ high genetic risk
  • annual MRI for women w/ personal history of breast CA and dense breast tissue or dx by age 50
39
Q

An MRA is used to evaluate:

A

Used to evaluate aorta, carotids, renal arteries, peripheral vascular system, intracranial
-Can see peripheral vascular disease

40
Q

What 2 emerging MRI applications?

A

Fetal MRI and cardiac MRI

Radiology (5 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions