Basics of MRI

Question 1

Principal of MRI

Answer 1

Proton spins are affected by a very strong magnetic field

They can absorb a small wavelength of light and then re-emitt, producing images

Question 2

Quench

Answer 2

The process of shutting down an MRI

Both expensive and dangerous due to the release of toxic gas

Question 3

Things that prevent patients from getting MRI

Answer 3

• Foreign bodies
• Contrast contraindication (AKI, pregnancy)
• Claustrophobia

Question 4

Foreign bodies on MRI

Answer 4

Appear as a “black hole”

Question 5

Gadolinium contrast

Answer 5

Question 6

Unlike iodinated contrast, gadolinium contrsat is not. . .

Answer 6

. . . nephrotoxic

So creatinine does NOT matter

Question 7

Nephrogenic systemic fibrosis

Answer 7

Question 8

Three main modes of MRI

Answer 8

T1

T2

Proton density

Question 9

HASTE

Answer 9

Rapid MRI sequence

Question 10

T1 features

Answer 10

Question 11

Best way to differentiate T1 and T2

Answer 11

Simple fluid is bright on T2

Question 12

Best way to differentiate contrast from noncontrast MRI

Answer 12

Nasal sinuses (highly vascular)

Question 13

T2 features

Answer 13

Question 14

Air artifact on MRI

Answer 14

Creates a shadowy, hazy area

Question 15

In phase / out of phase contrast

Answer 15

If something gets darker on out of phase, then it contains fat

This is what we use to differentiate myelolipomas as adrenal nodules on MRI!

Question 16

Where is the infarct on this MRI cardiac viability scan?

Answer 16