Pennsylvania Patient Safety Advisory Safety in the MR Environment: MR Safety Screening Practices ABSTRACT of the narratives of MR screening-related reports sub- Electromagnetic and ferromagnetic materials in close mitted to the Authority: proximity to a magnetic resonance imaging (MRI) An MRI scan of the patient’s right knee was ordered; scanner can be a hazardous safety risk to any individ- the patient had a pacemaker. ual near the scanner. To avoid injury from interference and attraction effects, individuals are screened before Patient was ordered an MRI of the brain. The patient entering the MRI scan room. The magnetic resonance was put on the schedule for 10 a.m. The nurse on (MR) screening process typically consists of interviews the floor called down and said he had a pacemaker. between MR personnel and patients or other non-MR The nurse filled out the [screening] form incorrectly. personnel needing access to the MRI scanner and The physician ordered an MRI on a patient with a completion of a questionnaire (MR screening form). pacemaker. The MR screening form contains questions to ask A patient required an MRI of the head. A technician individuals needing access to the MRI scan room in screened the patient and asked if there was anything order to identify potential contraindicated objects on in [patient’s] sweatpants pockets, to which the patient or in their bodies, such as an implanted cardiac pace- replied “no.” When the [MRI] magnet was started, maker. The magnetic field of the MRI scanner could a knife was pulled out of the patient’s pocket by the affect ferromagnetic objects implanted in an individual magnet. It stabbed [the patient] in the [arm]. The in such a way as to cause harm. In 2008, the Pennsyl- injury required staples. vania Patient Safety Authority received approximately A patient developed pain/tingling, during an 150 reports describing events in which the MR clini- MRI scan, where a plate and screw were located cal screening process was inadequate and, in some [implanted]. The patient had been prescreened. cases, erroneously permitted patients with implanted pacemakers and other ferromagnetic objects into A patient was cleared for metal through family inter- the MRI scanner room. Rigorous MR screening prac- view per ordering resident. The MRI study was started tices will help reduce hazards from contraindicated and a metal artifact was identified. The study was implants and ferromagnetic objects in close proxim- immediately canceled. A CT [computed tomography] ity to the MRI scanner. (Pa Patient Saf Advis 2009 scan of the head was done instead of the MRI. [The Mar;6[1]:20-6.) physician was] notified. A patient had a tissue expander noted on [screening form] checklist, but MRI was started. Upon review of initial images, a metal artifact was noticed and the Effective screening of patients and nonmagnetic scan was stopped. resonance personnel before entering the magnetic resonance imaging (MRI) scanner is an extremely Patient [was] ordered [an] MRI brain [scan]. The important process in ensuring the safety of individuals floor [staff] called to verify that patient [was] screened in the magnetic resonance (MR) environment. The and was told the patient was screened. [The] patient MR screening process reduces the likelihood of an arrived for test, and [staff] found that patient has a adverse event while the patient is inside the bore of pacemaker; a contraindication for the MRI. Patient the MRI system. did not receive MRI. In 2008, 148 reports were submitted to the Pennsyl- Patient was having an MRI of the left shoulder. [The vania Patient Safety Authority identifying a variety of patient] was wearing a long-sleeve sweater, and during problems related to inadequate screening practices of the course of the scan complained of a warm feeling individuals for metal exposure or orders written for on the right arm. Patient’s arm was repositioned away MRI scans of patients with MR contraindications (e.g., from scanner and a sponge was placed. After the scan permanent pacemakers). Most of the reports involved the patient showed the right arm [to a registered nurse patients with implanted devices such as pacemakers, (RN)], which had a 2-inch by 1-inch red patch with cardiac defibrillators, and aneurysm clips entering the a slightly blistered area in the center. The CT RN MRI scanner room or MR personnel realizing just looked at the arm and put ice on it. On inspection of before patients entered the MRI scanner room that the sweater, it [was noted that] it had a makeup of the patients had implanted devices. Other reports 18% metallic thread. identified MR screening forms with incorrectly or Sixty-eight reports (approximately 46%), by far the inadequately answered questions. For inpatient MRI most frequently reported MR-screening-related event scans, many reports described miscommunication related to implanted clinical devices with ferromag- between the referring department (e.g., medical/surgi- netic content received by the Authority, described cal) and the radiology department about an implant in patients with implanted cardiac devices getting past the patient. For perspective, the following are examples the safeguard of the screening process and entering the Page 20 REPRINTED ARTICLE - ©2009 Pennsylvania Patient Safety Authority Vol. 6, No. 1—March 2009 Pennsylvania Patient Safety Advisory MRI scan room or being stopped from entering the scan room by the final screening process. The next Table. List of Ferromagnetic Items and most frequently reported events included five reports Frequency of Reports of patients with aneurysm clips and four reports of FERROMAGNETIC ITEM NUMBER patients with imbedded bullets or BB pellets entering OF REPORTS the scan room or being stopped by the screening pro- Pacemaker/implanted cardiac device/ 68* cess before entering the scan room. Data could not heart valve be gleaned from 49 of the 148 total reports (approxi- Aneurysm clip 5 mately 33%) because the reports only indicated that Bullet/BB pellet/gunshot wound 4 patients were improperly screened. For a comprehen- Hearing aid/ear implant 3 sive list of types and frequency of ferromagnetic items Orbit (eye) metal 3 reported to the Authority, see the Table. Abdominal aortic aneurysm stent 2 In the majority of reports, MRI scans were ordered Acupuncture needle 1 for patients with some type of ferromagnetic or Inferior vena cava filter 1 potentially ferromagnetic medical implant. MRI scans “House-arrest” ankle bracelet 1 are typically contraindicated for patients with ferro- Knife 1 magnetic implants because of the potential for injury Metal artifact 1 from forces exerted on the implant by the magnetic Metal buckle 1 field of the MRI scanner and/or magnetic field inter- Metal plate/screw 1 ferences with the electromechanical operation of the Pain pump (implanted) 1 active implant. Another reason for the contraindica- Sweater (with 18% metal fabric) 1 tion is due to radio-frequency (RF) electromagnetic Tattoo 1 energy used during the scan process inducing electri- cal currents in electrically conducting implants. The Tissue expander 1 electrically induced currents may result in heating of Face mask (with metal nose piece) 1* the implant. Since MRI scans were ordered for those Unknown implant 1 patients, one apparent process breakdown may have Total 97** been staff not conducting or inadequately conducting * These two items were recorded on the same Authority report. patient histories or inadequately reviewing medical ** This total number of reports excludes the 49 reports received with descriptions of only improper screening and 2 reports records to determine patients’ metal exposure histo- concerning pregnant patients scheduled for MRI scans ries (e.g., implants). Another breakdown may be in (148 - 49 - 2 = 97). miscommunications between clinicians of patients’ histories. the MR environment, and the hazards associated with In addition to the reports of implants, one reported inadequate screening processes. The article will also event of interest that may not be typically considered provide guidance in developing effective MR screen- by clinical or MR technical staff involved a patient ing practices. wearing a sweater containing 18% metallic thread. According to the report, the patient experienced erythematous skin with blistering in the center of the MRI Technology mark. While it would be impractical to inspect the MRI is a noninvasive imaging technology used to clothing of all patients before performing an MRI image anatomy in multiple planes or slices.1 An scan, it may be prudent to perform a quick visual MRI scanner creates cross-sectional images using check of patients’ clothing for anything out of the electromagnetic fields, not ionizing radiation (x-rays) ordinary and/or have patients with suspect garments such as in CT scans. MRI scans can image structures change into gowns or scrubs for their MRI exam. that contain air and are not hindered by bone. The It should be noted that 74 of 148 reports demon- MRI scan is conducted with the anatomic structure strated that patients with MR contraindications of interest placed into the center of the bore (i.e., were identified during MR screening processes and the opening) of the MRI system. The MRI system stopped from entering the MRI scan room, poten- exposes the subject to electromagnetic fields, then tially preventing injuries. constructs the images by interpreting tissue reactions The information in this article is not comprehensive from the area of interest to the applied magnetic and but is presented as a guide for MR imaging facilities RF fields.1 The strength of the static magnetic field and departments in developing effective MR screen- of clinical MRI systems is typically between 0.064 ing practices. This article will discuss the boundaries and 3 tesla (T), which is measured at the center of and restrictions of the MR environment as they relate the bore of the magnet. However, some MRI systems to the safety of individuals entering that environ- used for research can have field strengths as high as ment. The article will also discuss the need for and 9.4 T (Earth’s magnetic field varies depending on the the process of screening individuals for metal expo- proximity to the magnetic poles but averages approxi- sure, including the clinical implantation of objects mately 0.00005 T, or 0.5 gauss (G) in North America or devices that may be ferromagnetic, before entering and continental Europe). Vol. 6, No. 1—March 2009 REPRINTED ARTICLE - ©2009 Pennsylvania Patient Safety Authority Page 21 Pennsylvania Patient Safety Advisory Due to the strong magnetic field of the MRI scanner, Figure 1. Model MR Facility Zone Configuration ferromagnetic objects external to the body can be pulled into the magnet bore of the scanner, known as the projectile effect. Additionally, the magnetic field can also affect implanted ferromagnetic objects (e.g., permanent pacemaker), applying attractive force even though the object is in the subject’s body. The mag- netic field may exert forces on an implanted object, potentially causing the object to move in the body, which could result in serious harm to an individual. (A more detailed discussion of the projectile effect will be discussed in an article in an upcoming issue of the Pennsylvania Patient Safety Advisory.) MRI systems also incorporate RF electromagnetic fields as part of the scanning process. The RF electromagnetic energy can potentially generate heat in conductive materials in or on the body. (For more information on the haz- ards during MRI scans, see the section “MR Hazards Associated with Ferromagnetic Implants.”) MR Suite Safety Boundaries The American College of Radiology (ACR), through Sample floor plan illustrating various safety level zones in a typical magnetic resonance suite. the formation of a blue ribbon panel on MR safety, (Reprinted with permission from the American Journal of developed the “ACR Guidance Document for Safe Roentgenology.) MR Practices.” The latest revision of the ACR docu- ment was published in 2007. While the 2007 ACR use of a locking system (e.g., key lock, elec- MR guidance document is not a regulatory standard tronic access control). for MR safety,3 at the time of this publication, it is widely used as an industry metric. Among the per- ■ Zone 4: formance criteria identified by the ACR panel is the — The area containing the MRI scanner (mag- designation of a four-zone model of integrated screen- net) and is associated with the strongest ing and access controls in the MR suite. Each zone in magnetic fields. Zone 4 should be clearly the model represents a different safety level of static marked as being potentially hazardous due to magnetic field exposure for the general public. The the strong magnetic fields. Zone 4 should also ACR panel defined the four zones as follows (also be marked with a red light and lighted sign see Figure 1):2 stating “The Magnet Is On.” ■ Zone 1: Figure 2 demonstrate examples of MR zone-level sig- — All of the areas, outside of the MR environ- nage. Through colors and text, the signs indicate the ment, that are freely accessible to the general level of hazard within each zone. public (e.g., corridors and entrances just out- The boundary in the MR system at which the static side the MR environment). magnetic field has diminished sufficiently to pose ■ Zone 2: no physical threat to the general public, but more specifically for individuals with implanted pacemak- — The area between the public accessible zone 1 ers, is known as the 5 G line. The 5 G line, which and the more strictly controlled MR environ- can extend in three dimensions around the magnet ments (zones 3 and 4). Zone 2 areas typically bore, defines the boundary of the area at which the include reception, waiting, and patient dress- magnetic field strength of the MRI system is above or ing and holding rooms. The general public is below 5 G (see Figure 3). The strength of the magnetic generally not free to move throughout zone 2 field increases exponentially approaching the magnet without the supervision of MR personnel. bore. For example, the magnetic field strength at the ■ Zone 3: center of a 1.5 T magnetic bore would be 15,000 G — The area in which free access by unscreened (1 T = 10,000 G). Within a few feet of the magnet non-MR personnel or ferromagnetic objects bore, some objects could be pulled into the magnet* or equipment is restricted. Serious injury or or may not operate properly.1 The line may not be death could result in zone 3 due to interac- limited to the MRI scan room and may vertically tions between the individuals, objects, or extend to the floors directly above and below the equipment and the MR environment’s static MRI system.1 The 5 G line from the MRI system will and magnetic fields. Supervision is under * The topic of ferromagnetic objects and the compatibility of the control of the appropriate MR person- medical equipment in the magnetic resonance imaging environ- nel. Access to zone 3 should be physically ment will be discussed in an article in an upcoming issue of the restricted from the general public through the Pennsylvania Patient Safety Advisory. Page 22 REPRINTED ARTICLE - ©2009 Pennsylvania Patient Safety Authority Vol. 6, No. 1—March 2009 Pennsylvania Patient Safety Advisory Figure 2. Examples of MR Zone-Level Signage Reprinted with permission from Newmatic Medical, Petaluma, California. vary depending on the type of MRI system, the field All non-MR personnel, patients, and visitors must strength of the magnet, and the presence, amount, undergo a MR safety screening process before being and configuration of magnetic shielding.1 permitted to enter zone 3 of the MR environment. The safety screening should be performed by level 2 MR Environment Site Access and Restrictions MR personnel only. According to the ACR guidance document, individu- als in the MR environment are categorized as either MR Safety Screening Process MR personnel or non-MR personnel. MR personnel The MR screening process is typically a multilevel are individuals working in, at least, zone 3 of the MR process consisting of the following: a preliminary environment who have successfully completed MR question-and-answer interview via a telephone call safety lectures or presentations approved by the MR when the appointment is scheduled; an MR screening medical director. MR safety training should be con- form filled out by the patient, or patient represen- ducted annually and should include documentation tative in the event the patient is nonresponsive, upon successful completion of the program by each impaired, or unable to complete the form (e.g., a individual. According to the ACR guidance docu- child) in the MR reception area at the time of the ment, individuals that have not successfully completed appointment; and a further screening by level 2 MR the MR safety training within the previous 12 months personnel before the patient enters the MRI scanner shall be referred to as non-MR personnel. room. The form contains questions to determine the MR personnel can further be broken down into level medical history and metal exposure history of the 1 and level 2 subcategories. Level 1 MR personnel are patient in relation to the MRI scan. If the patient’s individuals who have passed minimal MR safety train- history cannot be obtained, and if the MRI scan ing education to ensure their own safety when working cannot be rescheduled until such information can in zone 3 of the MR environment. Level 2 MR per- be obtained, then the patient should be physically sonnel undergo more extensive MR safety education examined by level 2 MR personnel for signs, scars, or in broader aspects of MR safety. For example, level 2 other marks that might be indicative of an implant. personnel will learn issues related to the potential for If a question exists regarding an implant or poten- thermal loading or burns and direct neuromuscular tial implant, the MR safety director should decide excitation from rapidly changing gradients. whether to proceed with the MRI scan. The Vol. 6, No. 1—March 2009 REPRINTED ARTICLE - ©2009 Pennsylvania Patient Safety Authority Page 23 Pennsylvania Patient Safety Advisory Figure 3. Illustration of 5 G Line in 2. Metals such as aluminum and titanium, which MRI Scanner Room are considered MR-safe, would trigger conven- tional detectors’ alarms. 3. Ferromagnetic objects on the patient could be missed by conventional detectors when the patient is in close proximity to an MR-safe metal such as that found on an MR-safe stretcher. The ACR guidance document and ECRI Institute recommend against using conventional metal detec- tors. The ACR guidance document does recommend the use of ferromagnetic-only detectors specifically designed for pre-MR screening. Before entering zone 3, any individual undergoing an Simplified illustration of an MRI scanner room showing the location MRI scan must remove all readily removable metal- of the 5 G line for a typical MRI system. While the illustration is lic personal items and devices on or in his or her two dimensional, it should be noted that the area of the 5 G line extends in three dimensions around the magnet bore. body (e.g., watches, jewelry, pagers, cell phones, body (Reprinted with permission from ECRI Institute, Plymouth Meeting, piercings [if removable], contraceptive diaphragms, Pennsylvania.) metallic drug delivery [transdermal] patches).2 All metallic items that individuals cannot (or will not) following are examples of the types of questions that remove before the MR scan must be positively identi- may appear on a typical MR screening form: fied for both ferromagnetic and thermal risks before ■ Have you ever had a prior Yes No the MR scan. (For more information on patients diagnostic imaging study or undergoing MR scans while wearing transdermal drug examination (e.g., MRI, CT, x-ray)? delivery patches, see the September 2006 Pennsyl- ■ Have you ever experienced Yes No vania Patient Safety Advisory article “Foiled Again! any problem related to a previous Risk from Transdermal Patches in MRI Procedures” MR procedure? [http://patientsafetyauthority.org/ADVISORIES/ ■ Have you ever been injured by Yes No AdvisoryLibrary/2006/Sep3(3)/Pages/18.aspx].) a metallic object or foreign body All patients, visitors, and non-MR personnel with a (e.g., BB, bullet, shrapnel)? history of potential internal ferromagnetic foreign objects must undergo further investigation before Facilities can refer to the sample MR screening form being permitted entrance to zone 3.2 Acceptable available from the Pennsylvania Patient Safety Author- methods of screening for internal ferromagnetic ity Web site at http://www.patientsafetyauthority.org as objects include patient history, plain x-ray films, prior a guide in developing a comprehensive MR screening CT or MR scans of the anatomic area in question form. All questions on the screening form should be (radiography can only identify radiopaque mate- answered completely to avoid confusion or misunder- rial and cannot characterize its ferromagnetic or standing as to the metal exposure history of the patient. The completed screening form should be reviewed with nonferromagnetic properties), or access to written the patient (or patient’s representative) by two separate documentation as to the type of implant or foreign MR personnel to verify completeness and accuracy. object that might be present.2 Any patients with a history of orbit trauma by a potential ferromagnetic Ferromagnetic detectors (capable of distinguishing foreign body that required medical attention (or occu- between ferromagnetic and nonferromagnetic mate- pational exposure to metal-working) should have their rial), designed specifically for pre-MR screening, orbits cleared by plain x-ray films.2 After identifying may also be used as an adjunct to the MR screening the presence and type of implant or foreign object in process but should not be used in place of the screen- the patient, an evaluation should be undertaken to ing process. Ferromagnetic detectors should only determine the relative MR safety of the implant or be used for detecting ferromagnetic objects external to patients before they can be brought into zone 4. object as it pertains to the particular patient, exam, At present, ferromagnetic detectors have not been MRI scanner, and scan parameters. This evaluation approved for detecting ferromagnetic objects inter- should be conducted by level 2 MR personnel, a MR nal to the patient. Ferromagnetic detectors can be radiologist, or the MR medical director. handheld devices, free-standing doorway portals, or pillar systems. Conventional metal detectors (unable Objects That May Be Present on or in the Body to distinguish between ferromagnetic and nonfer- Many ferromagnetic and nonferromagnetic objects romagnetic materials) should not be used for several could be present on or in the body. Some types of reasons, including the following: implants and other objects on or in the patient’s body 1. Ferromagnetic materials contained in nonfer- that may be encountered in the MR environment romagnetic metal enclosures may not trigger include the following (the list is not comprehensive):4 conventional detectors’ alarms. ■ Aneurysm clips Page 24 REPRINTED ARTICLE - ©2009 Pennsylvania Patient Safety Authority Vol. 6, No. 1—March 2009 Pennsylvania Patient Safety Advisory ■ Biopsy needles The amount of these forces may change (e.g., poten- ■ Breast tissue expanders and implants tially increase) with movement of the patient within the magnetic field of the MRI scanner. The rate of ■ Bullets change of the forces depends on the rate of motion ■ Cardiac pacemakers and implantable cardioverter of patient movement within the field; the greater defibrillators the patient movement through the magnetic field, ■ Cochlear implants the greater the forces acting of the implanted device. Therefore, when removing the patient from the ■ Coils, stents, and filters magnet’s bore, immobilization of the device and ■ Heart valve prostheses a deliberately slow, cautious, rate of removing the ■ Orthopedic implants patient may reduce the amount of the forces on the implant.2 ■ Tattoos, permanent cosmetics, and eye makeup RF Heating Effect ■ Transdermal patches RF electromagnetic energy, such as that produced dur- In his book Pocket Guide to MR Procedures and Metallic ing use of an RF coil during MRI scans, can induce Objects: Update 2001, Frank G. Shellock, PhD, lists electrical currents in electrically conductive materi- more than 900 objects by specific brand, model, and als (e.g., pacemaker lead wires) whether in or on the in some cases size that have been evaluated for safety patient. These induced currents can heat the conduc- in the MR environment.4 The list contains objects tive material, potentially leading to thermal injury such as those listed above, the highest magnetic field where the material is in contact with the patient. The strength of the MRI system used for testing, and the likelihood of thermal injury increases with increasing status of the object when subjected to that magnetic RF energy and/or with higher-field-strength MRI sys- field. The status designations include safe, condi- tems. The heating effect also depends on the distance tional, and unsafe with substatus designations for between the RF coil and the conductive material—for conditional and unsafe. The pocket guide is designed example, the closer the distance is between the RF as a reference source for MR personnel to ascertain coil and the conductive material, the greater the the safety of exposing patients or non-MR personnel likelihood of the patient experiencing thermal injury. with implants, devices, or materials to the MR Additionally, thermal injury to the patient can occur environment.4, * if the patient is in direct contact with the wall of the MR Hazards Associated with Ferromagnetic magnet bore or the RF coil. Positioning the patient Implants within the magnet bore is such a way as to avoid con- tact when possible, or positioning conductive leads Within the MRI system’s static magnetic field, fer- and cables to avoid contact with the bore can greatly romagnetic and other magnetic materials can be reduce the risk of thermal injury. influenced by rotational (torque) and translational forces. These forces could be dangerous for strongly MR Image Artifact ferromagnetic implants (e.g., aneurysm clips) by mov- Extraneous image information that distorts the ing or dislodging the implant from its location in the accurate depiction of the scanned anatomy is called patient. This movement could result in damage to the image artifact. This distortion in image quality affects tissues surrounding the implant, potentially leading the diagnostic value of the image. Artifacts typically to ruptured blood vessels1 and death. The effect of appear in images as distortions, unwanted signals the rotational force is to align the ferromagnetic, or or patterns, or areas of signal loss, known as signal magnetic, object parallel to the static magnetic field, voids.1 For accurate image reconstruction, the static which results in rotational movement. The amount magnetic field of the MRI system must be uniform of the rotational force on an object depends on the (homogeneity). Disruption in the uniformity of the object’s size, shape, and magnetic properties and MRI system’s static magnetic field can occur when on the magnitude of the static magnetic field of the ferromagnetic materials, and some nonferromagnetic MRI system.1 The rotational force is greatest at the materials—typically less severe—are present near the geometric center of the magnet bore, where the mag- scanned anatomy.1 This disruption occurs because netic field strength is greatest. Translational force is ferromagnetic materials will distort the magnetic field a linear force (linear movement), which can draw an of the MRI system. object into the magnet’s bore. The amount of transla- tional force on an object depends on the object’s size, Distortion can also result from RF energy pulses pres- shape, and composition and the static magnetic and ent in the scanned region, inducing electrical eddy spatial gradient fields at the location of the object.1 currents in electrically conductive materials, similar to the currents induced in the RF heating phenomenon. Signal voids can be seen in the MR image as a blacked- out portion of the scanned anatomy in the area of the * A recent reference publication on MRI safety, implants, and devices is available from Shellock titled Reference Manual for Mag- implant. A signal void could be misinterpreted or mis- netic Resonance Safety, Implants, and Devices: 2009 Edition. However, diagnosed as pathologies if the radiologist is unaware this reference was not reviewed for this article. of the implant or other conductive material.1 Signal Vol. 6, No. 1—March 2009 REPRINTED ARTICLE - ©2009 Pennsylvania Patient Safety Authority Page 25 Pennsylvania Patient Safety Advisory voids are typically a concern with high-field MRI sys- shortcomings in MR screening processes that could tems (e.g., 3 T). The level of artifact observed on an affect the safety of individuals entering the MR image depends on the magnetic field strength of MR environment. the MRI system and on the shape, orientation, and position of the material in the body. ■ Talk with appropriate staff to identify barriers to effective screening practices. Conclusions ■ Compare your facility’s MR screening form against Ferromagnetic materials, especially implants, in the the sample MR procedure screening form, available presence of the magnetic field generated by an MRI from the Pennsylvania Patient Safety Authority scanner can pose a serious risk to the patient under- Web site at http://www.patientsafetyauthority.org, going the MRI procedure. The magnetic field could to identify content that current forms may omit. potentially cause the implant to move or dislodge Notes from its location in the patient, which may result in ruptured blood vessels. Conducting a proper and 1. ECRI Institute. The safe use of equipment in the mag- thorough MR screen for potential ferromagnetic mate- netic resonance environment [guidance article]. Health rials of each patient or other individuals entering the Devices 2001 Dec;30(12):421-44. MRI scan room will greatly reduce or eliminate the 2. Kanal E, Barkovich A, Bell C, et al. ACR guidance docu- likelihood of adverse events in the MR environment. ment for safe MR practices: 2007. Am J Roentgenol 2007 Jun;188(6):1447-74. ? As part of a risk reduction strategy to reduce or elimi- nate adverse events related to MR safety screening 3. Gilk T. Ferromagnetically naked. Patient Saf Qual processes consider the following: Healthc [online]. 2008 Jul-Aug [cited 2009 Jan 6]. Avail- able from Internet: http://www.psqh.com/julaug08/ ■ Share this article with all staff involved with mri-safety.html. MR safety. 4. Shellock F. Pocket guide to MR procedures and metallic ■ Review your facility’s MR-related Incident object: update 2001. Philadelphia: Lippincott Williams & and Serious Event reports to address potential Wilkins; 2001. ? Self-Assessment Questions The following questions about this article may be useful for internal education and assessment. You may use the following 4. Conventional metal detectors should not be used to scan objects before entering the MRI scan room because of examples or come up with your own. which of the following? 1. The magnetic resonance imaging (MRI) system static mag- a. Ferromagnetic materials contained within non- netic forces’ influence on ferromagnetic objects that are ferromagnetic metal enclosures may not trigger implanted or imbedded in individuals includes all of the conventional detectors’ alarms. following EXCEPT: b. Metals such as aluminum and titanium (considered a. Radio-frequency heating MR-safe) would trigger conventional detectors’ alarms. a. Rotational movement c. Ferromagnetic objects on the patient could be missed by conventional detectors when the patient is in c. Translational movement close proximity to a MR-safe metal such as a MR-safe 2. Which of the following mechanisms causes heating of stretcher. conductive objects in or on an individual in the MRI d. All of the above. scan room? 5. An inpatient is scheduled for an MRI scan of his brain. a. Static magnetic field The patient arrives in the MRI department. During the b. Radio-frequency electromagnetic field MRI screening process, it is discovered that the patient has c. Gradient magnetic field an implanted pacemaker. 3. The magnetic resonance (MR) screening process is a multi- The following is a list of statements about the appropriate- level process and typically consists of all of the following ness of the MRI scan for this patient. Select the statement EXCEPT: that promotes the best outcome for the patient. a. Preappointment phone interview a. The MRI scan is of the patient’s brain, so there is no risk to the patient from, or damage to, the pacemaker. b. Interview by level 2 personnel before the patient enters the MRI scan room b. The pacemaker can be deactivated or reprogrammed without harm to the patient during the MRI scan. c. MR screening form completed by the patient or patient representative c. MRI scans are contraindicated for patients’ with implanted pacemakers. d. Interview by level 1 MR personnel while the patient is positioned on the MRI scan table by level 2 d. If the pacemaker’s programming is altered by the mag- MR personnel netic field, the pacemaker will revert back to original programming once the patient is out of proximity with the field. Page 26 REPRINTED ARTICLE - ©2009 Pennsylvania Patient Safety Authority Vol. 6, No. 1—March 2009 PENNSYLVANIA PATIENT SAFETY ADVISORY This article is reprinted from the Pennsylvania Patient Safety Advisory, Vol. 6, No. 1—March 2009. The Advisory is a publication of the Pennsylvania Patient Safety Authority, produced by ECRI Institute and ISMP under contract to the Authority. Copyright 2009 by the Pennsylvania Patient Safety Authority. This publication may be reprinted and distributed without restriction, provided it is printed or distributed in its entirety and without alteration. Individual articles may be reprinted in their entirety and without alteration provided the source is clearly attributed. This publication is disseminated via e-mail. To subscribe, go to https://www.papsrs.state.pa.us/ Workflow/MailingListAddition.aspx. To see other articles or issues of the Advisory, visit our Web site at http://www.patientsafetyauthority.org. Click on “Patient Safety Advisories” in the left-hand menu bar. THE PENNSYLVANIA PATIENT SAFETY AUTHORITY AND ITS CONTRACTORS The Pennsylvania Patient Safety Authority is an independent state agency created by Act 13 of 2002, the Medical Care Availability and Reduction of Error (“Mcare”) Act. Consistent with Act 13, ECRI Institute, as contractor for the Authority, is issuing this publication to advise medical facilities of immediate changes that can be instituted to reduce Serious Events and Incidents. For more information about the Pennsylvania Patient Safety Authority, see the Authority’s Web An Independent Agency of the Commonwealth of Pennsylvania site at http://www.patientsafetyauthority.org. ECRI Institute, a nonprofit organization, dedicates itself to bringing the discipline of applied scientific research in healthcare to uncover the best approaches to improving patient care. As pioneers in this science for nearly 40 years, ECRI Institute marries experience and independence with the objectivity of evidence-based research. More than 5,000 healthcare organizations worldwide rely on ECRI Institute’s expertise in patient safety improvement, risk and quality management, and healthcare processes, devices, procedures and drug technology. The Institute for Safe Medication Practices (ISMP) is an independent, nonprofit organization dedicated solely to medication error prevention and safe medication use. ISMP provides recommendations for the safe use of medications to the healthcare community including healthcare professionals, government agencies, accrediting organizations, and consumers. ISMP’s efforts are built on a nonpunitive approach and systems-based solutions.