MRI Safety Equipment Safety/Patient Safety

Question 1

The FDA recommends posting warning signs to indicate the _________ line.

Answer 1

5 Gauss

Question 2

FDA safety levels for RF exposure during MR examination are defined by SAR restrictions, which are imposed to reduce the risk of:

Answer 2

Systemic and/or thermal injury to patient

Question 3

FDA guidelines dictate a level of concern when RF energy absorption produces an increase in body temperature of:

Answer 3

1° Celsius

Question 4

Risk factors of MR exposure with regards to SAR include all of the following EXCEPT:

Answer 4

Hypotension

Question 5

What type of pulse sequence transmits the most RF to the patient and consequently can potentially have more SAR restrictions?

Answer 5

Fast spin echo

Fast spin echo sequences utilize ETL (echo train lengths/180° RF pulses) to reduce scan time, at the expense of increased RF power/absorption to the patient

Question 6

The fringe magnetic field:

Answer 6

Can cause nearby medical devices to malfunction

Question 7

Which of the following is regulated by the FDA?

Answer 7

Acoustic noise

Question 8

RF energy is:

Answer 8

Low energy, non-ionizing radiation

Question 9

ACR recommended Zone 1 signage designates an area intended for _________________.

Answer 9

General public

Question 10

ACR recommended Zone 2 signage designates an area intended for:

Answer 10

Unscreened MRI patients

Question 11

ACR recommended Zone 3 signage designates an area intended for:

Answer 11

Screened MRI patients/personnel

Question 12

ACR recommended Zone 4 signage designates an area intended for:

Answer 12

Screened MRI patients under constant direct supervision of trained MR personnel

Question 13

The magnetic field that the MR technologist is most exposed to would be the:

Answer 13

Static magnetic field

Question 14

The intensity limit for a static magnetic field in clinical use is limited by the FDA to what field strength? (Clinical imaging in patients over one month of age and above)

Answer 14

8.0 Tesla

Question 15

The intensity limit for a static magnetic field by the FDA for the entire population is?

Answer 15

4.0 Tesla

Question 16

The pulse sequence that should be utilized the least in a patient with implanted metallic hardware is:

Answer 16

Gradient echo

Gradient echo sequences lack a 180° RF pulse that aids in correcting local magnetic field inhomogeneities, found in metallic implants.

Question 17

A patient with a history of _______ should have their GFR checked prior to the administration of IV contrast.

Answer 17

All of the above

Kidney disease, hypertension, diabetes

Question 18

Adequate patient care dictates a patient having an MRI should be __________ monitored

Answer 18

Visually and/or verbally

Question 19

Patient types who may require additional monitoring while undergoing an MR exam might include:

Answer 19

All of the above
Claustro, Pediatric, unresponsive, limited vocal

Question 20

The effect by which a patient may experience a visual stimulation, described as “seeing stars”, is known as:

Answer 20

Magnetophosphenes

Question 21

When moving blood enters a magnetic field, an effect on the ECG seen as a “T wave swelling” or spike occurs, also known as:

Answer 21

Magnetohydrodynamic effect

Question 22

Regions of the body that do not quickly dissipate thermal absorption from SAR during MR procedures are

Answer 22

Eyes and testicles

Question 23

The following items are typically permitted access to enter a high field MRI system during an MRI guided core biopsy:

Answer 23

C and/or D

Aluminum interventional equipment, Sterile nonferrous biopsy tray

Question 24

Prior to entering the MRI scan room, a patient should be screened for:

Answer 24

All of the above

Surgical implants, Pregnancy, Prior trauma or injury

Question 25

During a quench, patients and employees should be evacuated from the scan room to prevent __________.

Answer 25

A and B
Ruptured tympanic membranes, Frostbite and asphyxiation

Question 26

The primary biological effect of radiofrequency fields is ____________.

Answer 26

Tissue heating

Question 27

As the flip angle is doubled, the RF absorption increases by a factor of __________.

Answer 27

4

Question 28

The minimum acceptable method for detection of intra-ocular ferrous foreign bodies is:

Answer 28

X-ray

Question 29

A more accurate method of detecting small intra-ocular ferrous foreign bodies is:

Answer 29

Cat Scan

Question 30

The percentage of patients reported to have reactions to gadolinium MRI contrast are:

Answer 30

Less than 1%

Question 31

It is ___________ that every patient having an MRI be provided auditory protection in the form ______________.

Answer 31

Recommended; earplugs and/or headphones

Question 32

The general public is limited to a magnetic field of ___________?

Answer 32

5 Gauss

Question 33

The FDA limit on time varying magnetic fields is __________.

Answer 33

Once the patient experiences peripheral nerve stimulation

Question 34

Cables from RF coils and gating leads should be:

Answer 34

Braided and positioned straight in the bore

Question 35

RF heating is more of a concern in ________ sequences.

Answer 35

Fast spin echo

Question 36

When would sterile technique be utilized?

Answer 36

When performing any procedure that would puncture a patient’s skin

Question 37

Risk factors of MR exposure with regards to SAR absorption include all of the following EXCEPT:

Answer 37

Hypotension

Question 38

The fringe magnetic field:

Answer 38

Specific absorption rate

Question 39

FDA limits for whole body SAR is ______ over 15 minutes of scanning.

Answer 39

4 W/kg
FDA limits for whole body SAR is 4 W/kg over 15 minutes of scanning