MRI

Question 1

What is an MRI?

Answer 1

non-invasive, cross-sectional imaging technology

Question 2

What is the most technologically advanced imaging modality to date?

Answer 2

MRI

Question 3

Which imaging modality produces high resolution image without radiation exposure?

Answer 3

MRI

Question 4

An MRI uses a ___________ _____________ & _______________ ____________ to create an image.

Answer 4

magnetic field & radiofrequency signals

Question 5

Images made in an MRI are based on measurements of what?

Answer 5

electrons emitted from hydrogen protons

Question 6

What are the 3 components of an MRI?

Answer 6

magnetic field, radiofrequency, and three gradient coils

Question 7

What do the three gradient coils provide?

Answer 7

“slices” in any direction

Question 8

Radiofrequency Coils

Answer 8

transmits a radiofrequency pulse, which alters alignment of protons

Question 9

How long does an MRI take?

Answer 9

20-90 minutes

Question 10

Axial

Answer 10

feet are coming toward you

Question 11

Sagittal

Answer 11

Left to right

Question 12

Coronal

Answer 12

Front to back

Question 13

What are the two different views provided w/an MRI?

Answer 13

T1 & T2

Question 14

How does water appear in a T1 view?

Answer 14

darker

Question 15

How does fat appear in a T1 view?

Answer 15

bright white

Question 16

How does water appear in a T2 view?

Answer 16

bright white

Question 17

How does fat appear in a T2 view?

Answer 17

darker

Question 18

What is the T1 view best used for?

Answer 18

anatomic detail

Question 19

What is the T2 view best used for?

Answer 19

pathological conditions & inflammation

Question 20

Gyri

Answer 20

folds of the brain

Question 21

Sulci

Answer 21

indentations or grooves of the brain

Question 22

Where does the CSF fill into?

Answer 22

sulci, fissures & ventricles

Question 23

What are the ABCDES of examining an MRI?

Answer 23

Alignment
Bone Signal
Canal Space/CNS
Disc Integrity
Edema
Soft Tissues

Question 24

Fracture lines appear as low-signal or dark on T1, T2, or both?

Answer 24

both

Question 25

Edema (inflammation)

Answer 25

abnormal fluid

Question 26

How does edema appear on T1 view?

Answer 26

low intensity (darker)

Question 27

How does edema appear on T2 view?

Answer 27

high intensity (bright white)

Question 28

How does muscular atrophy appear on T1 view?

Answer 28

bright white (fat)

Question 29

How does muscular atrophy appear on T2 view?

Answer 29

bright white (fluid)

Question 30

How is a Short Tau Inversion Recovery (STIR) adjusted? What adjustments are made to the image?

Answer 30

adjusted T1 image that suppresses fat (dark) & enhances fluid (bright white)

Question 31

How is Fluid Attenuated Inversion Recovery (FLAIR) adjusted? What adjustments are made?

Answer 31

adjusted T2 image that suppresses normal CSF fluid (makes it darker) to highlight other abnormalities

Question 32

When is FLAIR commonly used?

Answer 32

brain imaging

Question 33

Normal Pressure Hydrocephalus

Answer 33

abnormal build up of CSF in the ventricles of the brain

Question 34

What is the effect of NPH on the brain? How does it appear on an MRI?

Answer 34

increases pressure on the brain increase in ventricle size brain being "squished"

Question 35

What is the gold standard for intraarticular pathologies such as SLAP tears, labrum tears, & RTC tears?

Answer 35

coronal MR anthrography (MRA)

Question 36

What are hip MRI indications?

Answer 36

labrum

Question 37

What are knee MRI indications?

Answer 37

meniscus, cruciate ligaments, & collateral ligaments

Question 38

What are ankle/foot MRI indications?

Answer 38

stress & navicular fx

Question 39

What are shoulder MRI indications?

Answer 39

rotator cuff

Question 40

What are elbow MRI indications?

Answer 40

tendons

Question 41

What are wrist/hand MRI indications?

Answer 41

scaphoid & lunate fx

Question 42

What are the pros of an MRI?

Answer 42

- increased soft tissue detail & contrast - imaging in multiple planes w/o patient repositioning - changes & variations in bone marrow - NO IONIZING RADITION EXPOSURE

Question 43

What are the cons of an MRI?

Answer 43

- expensive - less available than a CT - increased time - claustrophobia - requires safety check

Question 44

What are safety considerations for an MRI?

Answer 44

- patient to answer safety screening beforehand - assess for absolute or relative contraindications

Question 45

What are contraindications to using an MRI?

Answer 45

- morbid obesity - claustrophobia - pediatrics - kidney disease - pregnancy