Magnetic Resonance Imaging

Question 1

How are coronal MRI images viewed?

Answer 1

from the front

Question 2

How are axial MRI images viewed?

Answer 2

from below

Question 3

How are sagittal MRI images viewed?

Answer 3

from left to right

Question 4

Disease processes that give rise to low signal intensity on T1 imaging give rise to ___ signal intensity on T2

Answer 4

high

Question 5

What gives rise to high signal intensity on a T1 image?

*light appearance

Answer 5

bone marrow

Question 6

What gives rise to low signal intensity on a T1 image?

*dark appearance

Answer 6

IVDs

Question 7

What gives rise to the lowest signal intensity on a T1 image?

*black appearance

Answer 7

CSF

Question 8

What gives rise to high signal intensity on a T2 image?

*light appearance

Answer 8

CSF and IVDs

Question 9

T1 images are made at ___ energy levels. Why?

Answer 9

High, so most of the energy from the radiofrequency remains in the tissues

Question 10

T2 images are made at ___ energy levels.

Answer 10

low

Question 11

Because T2 images are made at low energy levels, how does this effect the image?

Answer 11

They appear grainier and display less spatial resolution

Question 12

What do T1 images measure energy from?

Answer 12

Structures such as fat, which give up energy rapidly

Question 13

What do T2 images measure energy from?

Answer 13

Structures such as water, which does not readily give up energy

Question 14

T1 imaging measures energy ___ in the process of longitudinal remagnetization

Answer 14

early

Question 15

T2 imaging measures energy ___ in decay of transverse relaxation

Answer 15

late

Question 16

T2 imaging is valuable in detecting what?

Answer 16

inflammation

Question 17

In summary, ___ gives rise to high signal intensity on T1-weighted images and low to intermediate signal on T2

Answer 17

fat

Question 18

In summary, ___ gives rise to high signal intensity on T2-weighted images and very low signal on T1

Answer 18

water

Question 19

What structures show low signal intensity on all sequences?

Answer 19

Tendons, ligaments, menisci, and cortical bone

Question 20

Does red or yellow marrow display a higher signal intensity on T1 images?

Answer 20

yellow

Question 21

What type of signal intensity do muscles exhibit on T1 and T2 images?

Answer 21

intermediate signal intensity for both, although signal intensity slightly lower on T2

Question 22

What also gives rise to intermediate signal intensity on T1 and T2 images?

Answer 22

cartilage

Question 23

MRI is very sensitive for detecting changes and variations in bone marrow, which is important in the diagnosis of what?

Answer 23

• bone tumors
• stress fractures
• AVN

Question 24

What is the best modality for differential diagnosis between disk herniations and other causes of nerve root impingement?

Answer 24

MRI

Question 25

Is an MRI more sensitive than a bone scan for detecting bone metastases? Why or why not?

Answer 25

More, because it has the ability to stage neoplasms in bone and soft tissues along with extent of tissue invasion prior to surgery

Question 26

What are the contraindications to MRI?

Answer 26

• ferrous metals
• pacemakers
• claustrophobia