MRI

Question 1

MRI stands for

Answer 1

Magnetic Resonance Imaging

Question 2

MRI came into existence in the early

Answer 2

1980s

Question 3

Based on the principles of magnetic spectroscopy which is

Answer 3

the use of a magnetic field and radio frequencies to determine the chemical makeup of a substance

Question 4

indications for MRI

Answer 4

found in speciality vets, superior for demonstrating spinal cord, brain, and soft tissue structures like ligaments and cartilage in joints, desired modality since no radiation

Question 5

Magnets like those used in MRI scanners are

Answer 5

very dangerous

Question 6

Everyone entering an MRI room must be screened for

Answer 6

unsafe implants and any loose metal

Question 7

highest danger to staff and patients is the

Answer 7

projectile effect- the launching of a metallic object into the magnet by magnetic force

Question 8

Gauss (G)

Answer 8

imperial unit of measurement for magnetism

Question 9

Tesla (T)

Answer 9

most common measure of magnetism

Question 10

1T= _G

Answer 10

10,000

Question 11

Permanent magnets

Answer 11

two slabs of magnetic material facing each other; rend to be lower magnetic field strengths less than 0.3T

Question 12

electromagnetic or restive magnets

Answer 12

created by an electrical charge applied through copper wire wrapped around the center. also tend to be lower field magnets less than 0.6T

Question 13

superconducting magnets

Answer 13

massive electromagnets made of windings that are superconductive in very low temperatures. Most common. Liquid helium used to keep magnet active

Question 14

If part of the image as shown as bright or closer to white, it is described as having

Answer 14

a high signal intensity

Question 15

The reverse is true for anatomy seen in darker shades of gray; they are called

Answer 15

low signal intensity

Question 16

The goal in acquiring MRI images is to have a

Answer 16

high signal to noise ratio, higher amount of signal, better pictures

Question 17

is it possible to use MRI to image blood vessels without a contrast agent?

Answer 17

yes

Question 18

The contrast agent used for MRI is called

Answer 18

gadolinium

Question 19

What should be done before using gadolinium

Answer 19

P’s kidney function should be assessed because gadolinium is removed by the kidneys

Question 20

_ are often required by specialty practices before an MRI is performed

Answer 20

Referrals

Question 21

_ and _ required for MRI

Answer 21

anesthesia or sedation

Question 22

An MRI scan always starts with a low quality quick image called a

Answer 22

localizer

Question 23

Ferromagnetic shifting

Answer 23

containing metal implanted into a patient may move out of position with exposure to the magnetic field

Question 24

Heating of implanted metal that can cause

Answer 24

burning of the patient

Question 25

Assessment for MRI

Answer 25

checklist filled out by owner and pre-MRI x-ray if unsure of hx or possibility of pellets/bullets

Question 26

Specific absorption rate (SAR)

Answer 26

because animals cannot dissipate or radiate the heat from the radio waves in the same way as humans do through perspiration, cooling pack should be applied to dogs who are larger with less surface area

Question 27

Noise amount in decibels for MRI

Answer 27

60-90+