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Hoglund Brain Imaging Center. MRI Safety. MRI TERMINOLOGY. BIO EFFECTS (RISKS TO SUBJECTS). ACCESS ZONES. TRAINING GOALS. EMERGENCY PROCEDURES. SAFETY SCREENING. MAGNET QUENCH. MRI TERMINOLOGY. Tesla (T): magnetic field strength Gauss (G): another measurement of field strength
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Hoglund Brain Imaging Center MRI Safety
MRI TERMINOLOGY BIO EFFECTS (RISKS TO SUBJECTS) ACCESS ZONES TRAINING GOALS EMERGENCY PROCEDURES SAFETY SCREENING MAGNET QUENCH
MRI TERMINOLOGY • Tesla (T):magnetic field strength • Gauss (G): another measurement of field strength • Quench:to suppress or remove the magnetic field • Ferromagnetism:the attraction between a magnet and ferromagnetic materials such as iron
Earth = 0.5 Gauss 1.5 Tesla = 15,000 Gauss 3 Tesla = 30,000 Gauss
MRI Access Zones Patient Waiting Zone I Hallway Zone II Control Room Zone III Zone I: Trained personnel may escort and are responsible for subjects Zone II: Trained personnel must screen all subjects entering Zone IV Zone III and IV: Restricted Access Areas Scanner Zone IV
24 Hours a Day 7 Days a Week 365 Days a Year
Main Magnetic Field • Projectile or Missile Effect • Electronics Interference
Can enter scanner room Needs to be approved by MRI staff NOT MRI SAFE
Subjects with these items will NOT be scanned • Pacemakers/Defibrillators • Neurostimulators • Lyric Hearing Aids • Electronic Cochlear Implants May cause the device to MALFUNCTION and may cause DEATH
Gradient Field Hazards • Acoustic Noise • Peripheral Nerve Stimulation (PNS)
Acoustic Noise Problems • Annoyance • Verbal Communication Difficulties • Heightened Anxiety • Temporary Hearing Loss • In Extreme Cases, Permanent Hearing Impairment
Protect Hearing Ear Plugs are Mandatory in the Scanner
Peripheral Nerve Stimulation (PNS) Rapid switching of the gradients may cause tingling and/or twitching in the hands, feet, or face
Radio Frequency Pulses Can Cause • Tissue Heating • Antennae Effect
Excessive Heating • Power deposition measured by SAR (Specific Absorption Rate) • Dependent on several factors, including subject’s height, weight, and thermoregulation • Safety is regulated by FDA
Burns (Antenna Effects) • Equipment such as ECG leads and patient monitoring cables • Metal on or in clothing • Crossing arms/hands and legs/feet
Invisible metallic microfiber in clothing presents unrecognized MRI risk for cutaneous burn. A case of a thermal burn has occurred during MR imaging likely caused by silver-embedded microfibers in the fabric of an undershirt. As the prevalence of fabric containing nondetectable metallic microfiber increases in athletic and "tech" clothing, the importance of having patients change into safe facility-provided garments before MR imaging is emphasized.
First Degree Burn Considerations Transdermal Patch Metallic Nail Polish Body Piercings Bullets/BB’s Hearing Aids IUD Metal Shrapnel Hair Gel & Deodorant Tattoos
Screen for all metal implants and devices • Screen for surgeries • Judge on a case by case basis Be Conservative. If there is any question, call for clarification. 5-7894
Remove Personal Items • Research participant’s personal items must be secured in lockers. • Researchers must remove personal items before entering scanner room. Hair Pins/Clips Fit Bit Money Clips Jewelry Cell Phones Credit Cards Watch Keys Pens Coins Badges Lanyard
Remove Non-Projectile Items Credit Cards Flash Drives CD’s
Not Allowed In Zone IV Crash Cart AED Oxygen Tanks Metal or Electrical Equipment Emergency Response Team
“Playground” Rules • Respect Other Researchers • Scheduling • During In-Progress Scans • Respect Privacy of our Subjects • Send Required Paperwork