Brain Flashcards
Brain & Brain Safety
What must any patient with an implant provide during MRI screening?
An implant identification card
What should be verified before performing an MRI on a patient with an implant?
The implant’s MRI safety or conditional status for the specific field strength and exam
Where can you check the compatibility of an implant for MRI safety?
www.mrisafety.com
Why is it important to double-check with the implant manufacturer?
To confirm the implant is MRI safe.
What is the primary source of acoustic noise in MRI?
Gradients.
How can patients be protected from MRI noise?
By using earplugs and headphones.
What happens to noise levels as MRI field strength increases?
The noise becomes louder.
Why does MRI noise occur during scans?
Due to rapid alterations of currents within the gradient coils.
What type of radiation does MRI use compared to X-rays?
MRI uses non-ionizing radiation.
What are the three main imaging planes in MRI?
Sagittal (X-plane), Coronal (Y-plane), and Transversal/Axial (Z-plane).
How can patient burns be prevented during MRI?
Use blankets and cushions to position the patient and avoid direct skin contact with the bore surface.
What should be avoided with MRI cables to prevent burns?
Do not loop the cables.
What temperature can superconductive magnets in MRI reach?
As low as -269°C (-425°F, 4K).
What are the indications of quenching in MRI?
Loud noise, warning message, and/or tilting of an image on the screen.
What safety measures should be taken during a quench?
Stay low to the floor to avoid asphyxiation, frostbite, and injuries due to panic.
What is the fringe field in MRI?
Invisible lines of force extending beyond the magnet.
Are there any known risks of using MRI on pregnant patients?
No known risks, but MRI is reserved for very important problems or suspected abnormalities.
Why might MRI be safer for pregnant patients compared to X-rays?
MRI does not use ionizing radiation.
What potential effects might MRI have on developing fetuses?
Interaction of electromagnetic fields could potentially cause adverse effects, especially during the first trimester.
What are the components of an RF field in MRI?
RF transmit amplifier, RF antennas (coils), RF receive amplifier, and receive coil.
What can RF antennas in MRI cause?
Burn hazards.
What is SAR ?
Specific Absorption Rate
Why is SAR important in MRI?
It measures RF energy absorption and helps prevent thermal injury.
What is the primary purpose of MRI Zone 2?
Patient screening and preparation.
Who is allowed in MRI Zone 3?
Screened patients and personnel only.
What is MRI Zone 4?
The scan room
What are the three main planes used in brain imaging with MRI?
Sagittal, Coronal, and Axial.
What is MR Angiography (MRA) used for in brain imaging?
Evaluating cerebral arteries in cases of stroke, hemorrhage, trauma, AVM, aneurysm, etc.
What does Functional MRI (fMRI) detect?
Blood oxygen level–dependent (BOLD) changes indicating neuronal activity.
What is the purpose of Magnetic Resonance Spectroscopy (MRS)?
Quantifies metabolites and studies their distribution, displaying them as a spectrum in parts per million (ppm).
How can an EpiPen be used during an MRI emergency?
Administered to the thigh and held for 10-15 seconds.
What does SAR measure and why is it regulated by the FDA?
It measures RF energy absorption in watts per kilogram to prevent tissue heating and damage
Why is SAR regulated by the FDA?
to prevent tissue heating and damage.
Who can enter Zone 4?
accessible only to patients/personnel under direct supervision of MRI staff.
