MRI Hazards

Instead of x-rays and radiation, MRI uses a strong magnetic field and radio frequencies to produce the images.  Unlike a CT or x-ray, the MR system magnet is ALWAYS on.

Missile Effect:     

              Any ferromagnetic material will be attracted to the magnetic.  Scissors, IV poles, monitors and stretchers have “flown” through the air to the magnetic.  Several years ago in the USA, a child was killed when an oxygen cylinder was carried into the magnet room, and flew into the magnet crushing him.

Burns:

              Alternating magnetic fields used during the exam can induce electrical currents in conductive materials, cables and wires.  Reports of first, second, and third degree burns have been associated with the use of ECG wires and pulse oximeters.  A report was submitted to the FDA of a swann ganz catheter tip melting in a patient.

Contraindications

              The strong magnetic field may be hazardous to individuals (patients and staff) entering the MR room if they have not been screened by MR staff for contraindications.  Contraindications include pacemakers that may be turned off, metal chips in eyes that may heat up or move, and ferromagnetic aneurysm clips that may be pulled off a vessel.

MR Procedure

Exam length = 30 – 90 min

MR scan room door must be shut during the actual scans (2-7 min each).  If the door is opened during the scan, information may be lost.  Staff may not continually enter and leave scan room.  If necessary, staff may leave the magnet room to check IVAC etc, however door must be shut tightly again before the next scan is started.

Visual access of patient is restricted – area being scanned is centered within a 4-foot long tube. 


Before Transfer to MRI:

Patient Preparation:

IVAC’s may not enter the MRI room.  If patient must remain on IVAC, 5 extension sets must be added.

MR Checklist: must be completed.  If there are any questions regarding possible contraindications, contact MRI staff at ext. 35159 (UC) or 52207 (WC).

External Fixation Devices: most are magnetic and need to be removed. 

Swan Ganz: must be removed

Trachs: metal trachs must be replaced with plastic

Clamps: any metal clamps on chest tubes etc, must be replaced with plastic

Ventilator Circuit: respiratory therapy should bring over there own supplies and re-circuit the vent when they are finished.

Staff Preparation:

staff monitoring the patient during MR may not be pregnant

ensure staff have no other contraindications (aneurysm clips, pacemakers, cochlear implants, metal chips in eyes)

leave wallets, change, in CCTC

UC MR Monitoring Equipment and Accessories

Available for use during the MR exam:

ventilator (monaghan 225 ventilator – to be replaced with the BMD 1C-2A)

pulse oximeter

blood pressure

oxygen

suction (between scans)

1 MR pressure bag (to replace tyco)    

MR compatible stethoscope  

anesthesia (if prearranged with anesthesia dept)

Unavailable

ECG

Invasive BP

Arterial line

Temperature

VC MR Monitoring Equipment and Accessories

Available for use during the MR exam:

Ventilator   (BMD 1C-2A)

Millennia Monitor which provides: 

              ECG

              N20

              NIBP                                 

              Pulse Oximeter

              ETCO2

              Invasive Blood pressures (2)

              Respiration   

Stethoscope

oxygen

suction (between scans)

anesthesia (if prearranged with anesthesia dept)

Unavailable

Arterial line

Immediately prior to entering MRI

Patient:

ecg lead wires must be removed

tyco must be replaced with MR pressure bag

monitoring equipment used for transfer must be removed

backboard – all backboards have metal in them for support.  Backboard must be removed

Staff

Remove all metal e.g. ID badges (with magnetic strips), beepers, watches, costume jewelry, etc.

remove all objects from pockets (including pens, scissors)

patient’s chart may not enter room

Ensure equipment and belongings are not placed under stretcher or blankets.  They could become projectiles and cause serious injury to the patient or staff.

Before MR scan begins

Information from MR tech

use of oximeter

set BP to auto if required

tech will inform you how to contact them during scan

tech will inform staff remaining in magnet room on how to remove patient from magnet bore if there is an emergency

LHSCHealth Professionals

Last Updated March 30, 2010 | © 2007, LHSC, London Ontario Canada