MRI - MIDTERM L3 Flashcards
Magnetic fields used in everyday devices are typically __________
Low-frequency, Non-ionizing Radiation
It is a non-invasive procedure used to treat conditions like depression and anxiety which uses magnetic fields to stimulate specific areas of the brain, influencing neuron activity.
Transcranial Magnetic Stimulation (TMS)
TRUE OR FALSE
Magnetic fields in MRI can cause permanent sensations like feeling warm and can affect implanted medical devices such as pacemakers
FALSE
Magnetic fields in MRI can cause TEMPORARY sensations like feeling warm and can affect implanted medical devices such as pacemakers
EMFs stand for ______
Electromagnetic Fields
It is a form of therapy that uses EMF’s to promote healing in damaged tissues such as bones or muscles
Pulsed Electromagnetic Field (PEMF) Therapy
Which of the following is NOT a subtle effect of EMF’s on tissues ?
A. Altering Cell Behavior
B. Increasing Oxidative Stress
C. Decreasing Oxidative Stress
D. Nervous System Influence
C. Decreasing Oxidative Stress
TRUE OR FALSE
High-intensity magnetic fields, such as those used in certain industrial applications or scientific research, can have more direct effects on living tissues
TRUE
The effect of RF fields on living tissue primarily depends on four (4) factors, namely:
- Strength of the Field
- Frequency
- Duration of Exposure
- Type of Tissue
Tissues like _____,_____, and _____ absorb RF energy to varying degrees
- Muscle
- Fat
- Skin
TRUE OR FALSE
Muscle typically absorbs more energy than fat.
FALSE
Fat typically absorbs more energy than muscle.
How many is the temperature needed to cause thermal damage to tissues ?
10°C or More
These limits are based on the heating effects of RF fields which are considered the primary mechanism of harm
Regulation Standards
A measure of the rate at which the body absorbs RF energy
Specific Absorption Rate (SAR)
The exposure limits for RF fields vary depending on the __________
Frequency of the Radiation
Which two (2) regulatory bodies are designated to establish SAR limits to ensure safe levels of exposure ?
- Federal Communications Commission (FCC)
- Internal Commission on Non-ionizing Radiation Protection (ICNIRP)
MRI is generally considered safe during pregnancy, particularly in the ______ and _____ trimeesters
Second and Third
TRUE OR FALSE
MRI is rarely avoided during the first trimester unless absolutely necessary
FALSE
MRI is TYPICALLY avoided during the first trimester unless absolutely necessary
It is a rare but serious condition caused by the use of gadolinium in patients with compromised kidney function
Nephrogenic Systemic Fibrosis (NSF)
This pertains to the fear of enclosed spaces
Claustrophobia
What characteristics of MRI make it likely to cause discomfort or anxiety among claustrophobic patients ?
A. Narrow and Enclosed
B. Tight and Compressed
C. Thin and Secluded
D. Pressed and Pressured
A. Narrow and Enclosed
What medical condition is rendered to contraindicate MR Scanning as the magnetic field may interfere with electrical impulses in the heart, complicating heart rhythm control
Severe Cardiac Arrhythmias
Patients with implanted brain stimulators or other neural devices may be at risk as the strong magnetic field can interfere with the functioning of the device
Implanted Neural Stimulation Device
What type of tattoo ink can cause heating or discomfort during MRI ?
A. Cobalt-based
B. Dichromate-based
C. Mercury-based
D. Metallic-based
D. Metallic-based
The weight limit for many MRI machines is ______
Usually around 300 lbs / 136 kg
Pre-screening for metal objects before MR scanning includes (3):
- Screening of Patient and Personnel
- Metallic Objects
- Implanted Devices
MAGNETIC FIELD SAFETY ZONES
Public area, no magnetic field exposure
Zone I
MAGNETIC FIELD SAFETY ZONES
Area where patients and staff are screened before entering the MRI room
Zone II
MAGNETIC FIELD SAFETY ZONES
Controlled area where strong magnetic fields exist, and access is restricted to trained personnel and screened patients
Zone III
MAGNETIC FIELD SAFETY ZONES
MRI scanner room where the magnetic field is the strongest; only individuals with proper training and screening can enter this zone
Zone IV
This pertains to the safety zone principle where MRI rooms should be locked or restricted to only authorized personnel to prevent accidental exposure to strong magnetic fields
Restricted Access
This includes understanding the effects of magnetic fields, recognizing the hazards, and knowing emergency procedures
Staff Training
Healthcare workers and MRI technicians should be trained on how to handle emergencies such as patients experiencing adverse reactions, equipment malfunctions, or accidents involving metal objects
Emergency Procedures
This should be done to delineate safe zones where the field strength is safe for human exposure, ensuring that personnel avoid areas where the field is too strong and could pose a risk to their safety
Magnetic Field Mapping
Which are some of the vital signs requisite for detection of reactions to the procedures ?
Heart Rate and Blood Pressure
_______ or _______ can help alleviate claustrophobic stress and ensure the procedure can be safely completed
Sedation or The Use of an Open MRI Machine
These are cages which protect sensitive electronic equipment from electromagnetic interference
Faraday Shields
TRUE OR FALSE
Not having enough energy to remove electrons from atoms or molecules directly damage DNA or cause ionization in tissues
FALSE
Not having enough energy to remove electrons from atoms or molecules DOES NOT DIRECTLY damage DNA or cause ionization in tissues
The following are also listed contraindications for MRI EXCEPT:
A. Metal Implants or Foreign Objects
B. Cochlear Implants
C. Insulin Pumps
D. Peacemakers
D. Peacemakers (Pacemaker dapat)
TRUE OR FALSE
Prosthetic devices can also serve as a contraindication for MRI
TRUE
Which trimester is considered as the most contraindicated during an MRI scan ?
A. First Trimester
B. Second Trimester
C. Third Trimester
D. AOTA
A. First Trimester
