unit 1

Question 1

what does MRI stand for

Answer 1

magnetic resonance imaging

Question 2

T/F: MRI is a non-ionizing radiation modality

Answer 2

true , no known long term effects

Question 3

how does MRI create an image ?

Answer 3

images are based off of the body’s natural hydrogen atoms

Question 4

if a patient has a lump or specific area of pain how do we mark it?

Answer 4

vitamin E capsule , shows up bright in MRI imaging

Question 5

what type of patient will require screening done by spouses, family members, medical chart , and or additional exams

Answer 5

patients that are poor historians

Question 6

if a patient has suspected intra occular metallic foreign bodies , how do you clear the patient

Answer 6

orbit x ray, cleared by radiologist

Question 7

can a pregnant patient have contrast ?

Answer 7

no, as it can cross the placental barrier

Question 8

if an MRI technologist is pregnant, what should they avoid?

Answer 8

entering the scan room during an active scan

Question 9

if a site has a compatible oxygen tank that can be taken into the room what are they usually made of ?

Answer 9

aluminum material

Question 10

most common hearing protection in MRI

Answer 10

ear plugs (foam)

Question 11

what causes the noise from the MRI machine

Answer 11

switching of gradient magnetic fields

Question 12

hearing protection is required, foam ear plugs reduce the noise about ____

Answer 12

15 decibels is all

Question 13

T:F/ temporary hearing loss may occur after the exam

Answer 13

true

Question 14

what should you do to prevent antenna effect , loop burns

Answer 14

make sure coil cables are not in direct contact with the patients bare skin

Question 15

if a patient cannot be contacted verbally and visually they require more monitoring , or if they cannot communicate well. what would you use ?

Answer 15

pulse oximetry
ECG
blood pressure

Question 16

what causes the hearing in MRI?

Answer 16

RF (radio frequency) pulses

Question 17

SAR

Answer 17

specific absorption rate

Question 18

SAR is expressed in

Answer 18

W/kg, watts per kilogram

Question 19

whole body SAR

Answer 19

<4.0 W/kg

Question 20

what patients tend to have a higher SAR

Answer 20

larger patients

Question 21

how to reduce SAR

Answer 21

using fewer slices & using a 1.5 T vs a 3.0 T

Question 22

average total exam time without contrast, repeats, or special sequences etc

Answer 22

30-45 minutes

Question 23

the main effect of the RF exposure is

Answer 23

tissue heating

Question 24

sensation of flashes of light, originates from stimulation by the induced electrical field

Answer 24

magnetophosphenes

Question 25

signal misrepresentation or interruption

Answer 25

artifact

Question 26

which plane divides the part into superior and inferior portions

Answer 26

axial

Question 27

what plane divides the part into anterior and posterior portions

Answer 27

coronal plane

Question 28

most common chemical used in MRI to cool the magnet and provide the magnetic the ability to create a magnetic field

Answer 28

liquid helium

Question 29

repelled by the magnet, water and most biological tissue falls in this category

Answer 29

diamagnetic

Question 30

usually means better image quality, but longer scan time

Answer 30

higher NEX/NSA

Question 31

the staff technologist is usually only exposed to the _____ field while working

Answer 31

static

Question 32

there is a theoretical risk to the fetal ____ for a pregnant patient or worker , but not proven

Answer 32

hearing

Question 33

what MR personnel supervises the day to day safety of the unit

Answer 33

MRSO

Question 34

rotational force that results from the magnetic force on an implanted device, such as a stent or clip

Answer 34

torque

Question 35

during a quench cryogens are released which can lead to

Answer 35

hypothermia
cold burns
asphyxiation

Question 36

the waiting room or area where the patient may be screened , change into their gown , and remove ferromagnetic objects and other devices it typically in zone

Answer 36

2