MRI Safety Exam - University of Delaware



MRI Safety ExamThe three types of magnetic fields used in MRI that are of concern in MRI safety are the ______ magnetic fields.static, alternating, and RFstatic, gradient, and RFgradient, dynamic, and RFgradient, dynamic, and staticThe primary hazard associated with the static magnetic field in the MRI environment isIts interaction with metallic objects.Heating in the tissues of the body.Hearing damage.Fires or burns caused by induction of electrical current in conductors.The maximum static magnetic field strength allowed for clinical imaging in the U.S. as defined by the FDA is _____ Tesla.2468The potential dangers associated with metallic implants in the MRI environment areheating, artifact formation, and bleeding.heating deflection, and artifact formation.deflection, artifact formation, and bleeding.deflection, heating, and arrhythmia.The primary hazard associated with gradient magnetic fields in the MRI environment istheir interaction with metallic objects.heating in the tissues of the body.hearing damage.tires or burns caused by induction of electrical current in conductors.The term used to describe the amount of RF power absorbed in a unit of tissue in a unit of time isunit absorbed dose.radiofrequency equivalent man.specific absorption rate.British thermal unit.7.The primary hazard associated with RF in the MRI environment isits interaction with metallic objects.heating in the tissues of the body.hearing damage.fires or burns caused by induction of electrical current in conductors.8.The primary potential biological response to RF in the MM environment isits interaction with metallic objects.heating in the tissues of the body.hearing damage.induction of electrical current in conductors.9. SAR is measured inWatts/kilogram (W/kg).milliTesla/meter (mT/m).Tesla/second (T/s).radiofrequency equivalent man (rein).10.A known biological risk associated with the static magnetic field istissue heating.cardiac arrhythmia.none.fracture non-union.11.SAR limits are monitored by the MRI system during an exam using pulse sequence parameters and the patient’sheight.weight.mass.girth.12.The maximum allowed SAR value in the U.S. as defined by the FDA for whole- body MRI imaging is1 W/kg.2 W/kg.3 W/kg.4 W/kg.13.The maximum allowed SAR value in the U.S. as defined by the FDA for head MRI imaging is1.4 W/kg.2.6 W/kg..3.0 W/kg.4.3W/kg.14.The primary hazard associated with a superconducting magnet quench isasphyxiation.hearing damage.ferromagnetic projectiles.patient bums.15. The noise created by the gradients in an MR imagercan cause patient anxiety. interferes with ability of the Technologist and patient to communicate. can permanently damage hearing. all of the above.16.The primary hazard of handling liquid cryogens isasphyxiation.poisoning. frostbite. hearing damage.17.The FDA ______ MRI scanning of pregnant patients in the U.S.prohibitsrecommends allowsneither prohibits nor recommends.18.Electrical current can be induced in electrical wires during MRI scanning if the wires arebare.looped or crossed.large.broken.19.The area around an MRI magnet wherein the static magnetic field is strong enough to interfere with cardiac pacemakers and other medical devices is called heexclusion zone. fringe field.intrusion zone. forbidden zone.20.The static magnetic field strength that can interfere with cardiac pacemakers and other implanted medical devices is Gauss or Tesla.5; 0.50.5; 50.05; 0.0055; 0.000521.The most reliable source of MRl safety information about a medical implant isthe patient.the referring physician. implant manufacturer.MM site medical director.22.Cardiac pacemaker wires in the heart, but no control module in the patients’ chest is in the MRI environment.unsafeconditionally safesafe23.An implanted drug infusion pump is ______ in the MRI environment.unsafeconditionally safesafe24.If a patient presents to the MRI site with a history of metal slivers in the eyesthe exam should be canceled.orbit radiographs should be taken to assure the absence of metal in the orbits.the scan should be performed if the injury was six or more weeks prior.the scan can be performed safely.25.If a patient presents to the CBBI MRI facility with a history of a bullet or shrapnel woundthe exam should be canceled.the exact location of remaining metal fragments should be assured.the scan should be performed if the injury was six or more weeks prior.the scan can be performed safely.26.The danger of exposing a person with a cardiac pacemaker to the MRl environment is:the pacemaker programming could be erased.the reed switch will be stuck open or closed.an electrical current could be induced in the lead wires.all of the above.27.The primary danger of exposing a person with an implanted ferromagnetic intracerebral aneurysm clip to the MRI environment isdeflection of the clip, tearing it away from the vessel.ferromagnetic attraction of the clip, pulling it out of the patient’s skull.causing seizures in the patient.cardiac arrhythmia.28.The danger of exposing a person with an internal cardiac defibrillator to the MRI environment is related to thestatic field.gradient field.RE field.all of the above29.The danger of exposing a person with metal slivers in their eyes to the MRI environment is related to the _____ field(s).staticgradient and RFsecondaryelectrical30.The danger of exposing a person with retained pacemaker wires (no pulse generator) to the MR environment is related to the ________ field(s).staticgradient and RF secondaryelectrical31.The strongest magnetic field used in MRI is the ________ field.a) shimb) fringec) primaryd) electrical32.The three classifications of metals in order of strongest magnetic interaction area) ferromagnetic, diamagnetic, paramagnetic.b) ferromagnetic, paramagnetic, diamagnetic.c) paramagnetic, nonmagnetic, neomagnetic.d) diamagnetic, ferromagnetic, perimagnetic.33.The term for the movement of a paramagnetic object by a magnet isa) deflection.b) attraction.c) repulsion.d) induction.34.The term used to identify the part of the primary magnetic field that extends past the magnetic housing is the ________ field.a) secondaryb) exclusionc) fringed) deflection35.The danger of having ferromagnetic objects in the magnetic field is that they cana) become projectiles.b) burn patients.c) quench the magnet.d) explode.36.The area of the body where metallic foreign bodies are most dangerous for MRI are thea) heartb) eyesc) major arteries, veins, or nervesd) braine) all of the above37.The area an MRI magnet wherein the magnetic field is strong enough to interfere with medical devices is thea) fringe fieldb) exclusion zonec) magnet zoned) intrusion zone38.The only type of MRI main magnet can be switched off when not in use is the _________ magnet.a) resistive b) permanentc) superconductingd) semiconducting39.The type of MRI main magnet that has the strongest magnetic field is the _______ magnet.a) resistive b) permanentc) superconductingd) semiconducting40.Patients who have cardiac pacemakers are ________ for MRI.a) strictly contraindicatedb) safe six weeks after implantationc) usually safe dependent on specific modeld) safe41.Patients who have surgical clips in the chest, abdomen, or pelvis are ________ for MRI.a) strictly contraindicatedb) safe six weeks after implantationc) usually safe dependent on specific modeld) safe42.Patients who have intravascular coils, filters, and stents are ________ for MRI.a) strictly contraindicatedb) safe six weeks after implantationc) usually safe dependent on specific modeld) safe43.Patients who have prosthetic heart valves are _______ for MRI.a) strictly contraindicatedb) safe six weeks after implantationc) usually safe dependent on specific modeld) safe44.Patients who have metal attached to a bone are _______ for MRI.a) strictly contraindicatedb) safe six weeks after implantationc) usually safe dependent on specific modeld) safe45.Patients who have vascular clips in their brain are _________ for MRI.a) strictly contraindicatedb) safe six weeks after implantationc) usually safe dependent on specific modeld) safe46.Patients who have internal cardiac defibrillators are ________ for MRI.a) strictly contraindicatedb) safe six weeks after implantationc) usually safe dependent on specific modeld) safe47.Patients who have internal neurostimulators are __________ for MRI.a) strictly contraindicatedb) safe six weeks after implantationc) usually safe dependent on specific modeld) safe48. The primary danger associated with secondary magnetic field is:a) deflectionb) exclusionc) attractiond) induction of currents into conductors.49.The only time a technologist should quench a superconducting magnet isa) if an object is stuck to it.b) if a person’s life is in danger by a metallic object that is stuck to it.c) if the service engineer is present.d) if the magnet room needs cleaned.50.If there is a medical emergency in the magnet room, the first thing an operator should do isa) call for help.b) start CPR.c) remove the patient from the magnet room.d) quench the magnet.51.If a magnet quenches and the gases are venting into the magnet room with a patient in it, an operator shoulda) gain access to the room, even if they have to break the window.b) wait for the gases to dissipate, then enter the room.c) instruct the patient to lie on the floor.d) call for help.52.If a magnet and the gases are venting into the magnet room, any person in the magnet room shoulda) call a trained service engineer.b) stay near the floor and get out if possible.c) shut off the magnet.d) stand up in a corner of the room.53.The only people who should handle cryogens area) technologists.b) physicians.c) magnet service personnel.d) patients.54.In case of a small fire in the magnet room, a technologist shoulda) evacuate the patient from the room.b) turn off the power to the MRI room.c) stay as near to the room as possible to assure magnet.d) all of the above, in that order.55.In case of a large fire in the magnet room, an operator shoulda) evacuate the patient from the room.b) quench the magnet.c) turn off the power to the MRI system.d) all of the above, in that order.56.The FDA _______ MRI scanning of pregnant patients in the U.S.a) prohibits.b) recommends.c) allows.d) neither prohibits nor recommends.57.If a patient presents to the MRI site with an implanted arterial stenta) the exam should be cancelled.b) the specific model of the implant should be researched for MRI safety.c) the scan should be performed if the implantation was six or more weeks prior.d) the scan can be performed safely.58.If the patient presents to the MRI site with an implanted vena cava filtera) the exam should be cancelled.b) the specific model of the implant should be researched for MRI safety.c) the scan should be performed if the implantation was six or more weeks prior.d) the scan can be performed safely.59.If a patient presents to the MRI site with a history of a bullet or shrapnel wounda) the exam should be cancelled.b) the exact location of the remaining metal fragments should be assured.c) the scan should be performed if the injury was six or more weeks prior.d) the scan can be performed safely.60.The primary danger of exposing a person with an intracerebral aneurysm clip to the MRI environment isa) deflection of the clip, tearing it away from the vessel.b) ferromagnetic attraction of the clip, tearing it away from the vessel.c) an electrical current could be induced in the clip.d) all of the above.ADDITIONAL QUESTIONSA patient with a known metallic object (can be either surgically placed or fragments from an accident.) comes to MRI for a scan. The patient has successfully undergone multiple MRI exams both at other sites. Can it be assumed that the patient will have no adverse effects from this next scan or any future exams due to the presence of the metallic object? Give a short explanation for your answer.5037455705485000You enter the MRI research facility to find your MRI safety instructor pinned to the magnet by a large oxygen tank (or a chair). What do you do – call 911? Call the service engineer? Do you quench the magnet? (Careful here – he’s a nice person – usually.) ................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download