Week 2 Flashcards
What is malpractice?
The improper or illegal activity and treatment of a patient.
Define Negligence
Failure to fulfill professional obligations of expected standard of care
What is the Fringe field?
The magnetic field that extends outside the confines of the physical bore, forming a perimeter
What does Gauss refer to?
The conversion measurement of Tesla
What is the doctrine of legal liability?
Respondeat Superior
What does the Latin phrase “Res ipsa Loquitur” generally mean?
It speaks for itself
What is the relationship between magnet strength and fringe field?
The strength of the fringe field is directly related to the strength of the magnet
What is the conversion of Tesla to Gauss?
10,000 G = 1 T
Why is radio frequency shielding installed?
To block out random signals from the MRI exam room
What does SAR stand for?
Specific absorption rate
What is specific absorption rate?
The amount of radio frequency power absorbed per unit of mass per patient, causing heating of tissue.
What is the unit of measurement for SAR?
W/Kg (Watts per Kilogram)
What are the two types of SAR?
- Local: specific area of body
- Global: systemic body
The FDA has guidelines for specific absorption rate. What is the limit for the whole body?
4 W/Kg at 15 minutes
What is the FDA SAR limit for the head?
3 w/kg at 10 mins
What is the FDA SAR limit of the torso?
8 w/kg at 5 mins per gram
What is the FDA SAR limit for an extremity?
12 w/kg at 5 mins per gram
What is the FDA limit on core body temperature?
1°C
What are the three types of informed consent?
- Written.
- Verbal.
- Implied
What is PHI and who is it enforced by?
Protected health information; HIPAA
What does HIPAA stand for?
Health insurance portability and accountability act
What are the three foundational principles of the patient bill of rights?
- Privacy.
- Healthcare proxy.
- Research participation.
Define contraindication
A potential hazard that can injure or harm a patient
What are examples of contraindications for MRI?
- Cardiac pacemaker.
- Implantable Cardioverter defibrillators (ICD)
- Intracranial aneurysm clips
- Tissue expanders.
- Metallic presences
Give examples of MRI unsafe ferromagnetic metals
- Iron.
- Cobalt.
- Nickel.
- Steel
Give examples of MRI safe, non-ferromagnetic metals
- Titanium.
- Copper.
What are the four precautions a technologist must take with IV contrast administration?
- Low GFR/kidney issues.
- Pregnancy.
- Hemolytic abnormalities/blood disorders.
- History of allergic reactions to contrast.
What severe condition can result from using contrast on a patient with weak kidneys?
Nephrogenic systemic fibrosis (NSF)
What is the safety status of tattoos in MRI?
Generally safe, but unprofessional work can leave metallic debris in the skin, which causes burns
What is the safety status of medication patches on a patient in MRI?
Unsafe, advise removal. Patches could contain foil coatings, which can cause burns.
What is the safety status of monitoring devices used in MRI?
Generally MRI safe, but follow guidelines and vendor safety manual
What is the safety status of body jewelry in MRI?
MRI unsafe, advise removal to eliminate risk of magnetization and burning
What is decoupling?
The creation of unintended circuits that causes heat and burns. MRI cables must never be looped or crossed.
What is Cryogen?
Liquid helium
At what temperature must liquid helium be kept at?
-269°C or 4°K
What is quenching?
The emergency magnet shut off. Includes the rapid boil off of cryogen within the MRI scanner.
What steps must the technologist take when an emergency quench is necessitated?
- Remove patient from the bore of the magnet.
- Leave exam room while staying low to the ground
- Shut and lock door.
- Immediately get to a safe zone
Why must you leave the exam room (1) quickly and (2) low to the ground after an emergency quench?
- You must leave the room as quickly as possible because, as the cryogen is boiled off, the internal pressure of the exam room increases, and may rupture eardrums.
- As the helium is boiled off, the gas rises to the top of the room. This means the oxygen is compressed to the lower portion of the room.
What steps must the technologist take in the event of a projectile in the exam room?
- Remove patient from the bore and exam room
- Close exam room door and contact vendor field engineer.
- If the projectile causes the patient to become stuck, this necessitates a quench.
The MRI magnet’s force pulls projectiles at an exponential rate. If an object is 5 pounds at 10 feet away from the magnet, how many pounds would it feel like when it’s distance from the magnet is halved to 5 feet?
20 lbs. If you halve the distance, you quadruple the force weight.
What two things must the technologist keep in mind when dealing with a fire in and around the MRI suite?
- Any fire extinguisher used must be MRI safe
- Electrical fires call for dry powder or CO2
What temperature and humidity must be MRI environment be kept stable at?
69°F/21°C and 50-70% humidity
Describe the designated safety zones in an MRI suite.
- Waiting room, registration, building entrance, first line of patient screening.
- Patient changing rooms, second line of patient screening done by the technologist
- MRI, control room, patient in gown, no metal.
- MRI scanning exam room
What is gadolinium?
The IV contrast of MRI
What are some side effects of using gadolinium IV contrast?
- Headaches.
- Nausea
- Dizziness.
- NSF.
- Feeling of coldness at injection site.
What percentage of patients experience side effects from gadolinium use?
Between 1% and 5%
Drinking a lot of water is important for patients who have received gadolinium. How quickly should the patient urinate after the injection?
Within 3 to 4 hours
What is the unit of measurement for acoustic noise?
A-weighted decibels (dBa)
The FDA requires hearing protection for exposure to any acoustic noise greater than what?
> 99 dBa
How many decibels can the acoustic noise created by an MRI scanner reach?
> 120 dBa
What is the safety status of pacemakers in MRI?
MRI unsafe. There are some conditional pacemakers that require intense monitoring and an on-site cardiologist.
What is the safety status of Foley catheters in MRI?
MRI safe, as long as there is no thermocouple.
What is the safety status of diabetic infusion pumps in MRI?
MRI unsafe, as the battery will die inside the magnet
What is the safety status of a tibial halo in MRI?
MRI conditional, check with physician or hand magnet
What is the safety status of nasogastric tubes in MRI?
MRI safe
What is the safety status of oxygen systems in MRI?
MRI safe, as long as there are no ferromagnetic tanks used
What is asepsis and what are the two types?
A sterile environment, free of microorganisms
1. Medical: inhibits the growth and spread of germs
2. Surgical: destroys all germs immediately
What are fomites and give examples
Nonliving vehicles for pathogen transmission, like door handles, cushions, and sponges
What are vectors and give examples
Living vehicles for pathogen transmission, like a patient, insects, or animals
What is an HAI and give examples
Hospital associated infection
1. Central line associated bloodstream infection (CLABSI)
2. Catheter associated urinary tract infection (CAUTI)
3. Surgical site infections (SSI)
4. Ventilator associated pneumonia (VAP)
Describe the cycle of infection
- Pathogen
- Reservoir
- Exit
- Transmission
- Entry
- Host