Editing Magnetic resonance imaging (section)

==Safety==
{{Main |Safety of magnetic resonance imaging}}

MRI is, in general, a safe technique, although injuries may occur as a result of failed safety procedures or human error.<ref>{{cite journal |doi=10.1007/s40134-015-0122-z |title=Lessons Learned from MRI Safety Events |journal=Current Radiology Reports |volume=3 |issue=10 |year=2015 | vauthors = Watson RE |s2cid=57880401 }}</ref> [[Contraindications]] to MRI include most [[cochlear implant]]s and [[Artificial cardiac pacemaker|cardiac pacemakers]], [[Fragmentation (weaponry)|shrapnel]], and metallic [[foreign body|foreign bodies]] in the [[Orbit (anatomy)|eyes]]. [[Magnetic resonance imaging in pregnancy]] appears to be safe, at least during the second and third [[Pregnancy|trimesters]] if done without contrast agents.<ref name="MervakAltun2019">{{cite journal | vauthors = Mervak BM, Altun E, McGinty KA, Hyslop WB, Semelka RC, Burke LM | title = MRI in pregnancy: Indications and practical considerations | journal = Journal of Magnetic Resonance Imaging | volume = 49 | issue = 3 | pages = 621–631 | date = March 2019 | pmid = 30701610 | doi = 10.1002/jmri.26317 | s2cid = 73412175 }}</ref> Since MRI does not use any ionizing radiation, its use is generally favored in preference to [[X-ray computed tomography|CT]] when either modality could yield the same information.<ref name="iRefer">{{cite web |title=iRefer |url=http://www.rcr.ac.uk/content.aspx?PageID=995 |publisher=Royal College of Radiologists |access-date=10 November 2013 |archive-date=3 February 2014 |archive-url=https://web.archive.org/web/20140203182954/http://www.rcr.ac.uk/content.aspx?PageID=995 |url-status=dead }}</ref> Some patients experience claustrophobia and may require sedation or shorter MRI protocols.<ref>{{cite journal | vauthors = Murphy KJ, Brunberg JA | title = Adult claustrophobia, anxiety and sedation in MRI | journal = Magnetic Resonance Imaging | volume = 15 | issue = 1 | pages = 51–4 | year = 1997 | pmid = 9084025 | doi = 10.1016/s0730-725x(96)00351-7 | publisher = Elsevier BV }}</ref><ref>{{Cite journal|last1=Shahrouki|first1=Puja|last2=Nguyen|first2=Kim-Lien|last3=Moriarty|first3=John M.|last4=Plotnik|first4=Adam N.|last5=Yoshida|first5=Takegawa|last6=Finn|first6=J. Paul|date=2021-09-01|title=Minimizing table time in patients with claustrophobia using focused ferumoxytol-enhanced MR angiography ( f -FEMRA): a feasibility study|journal=The British Journal of Radiology|language=en|volume=94|issue=1125|pages=20210430|doi=10.1259/bjr.20210430|pmid=34415199|pmc=9327752 |issn=0007-1285}}</ref> Amplitude and rapid switching of gradient coils during image acquisition may cause peripheral nerve stimulation.<ref>{{cite journal | vauthors = Klein V, Davids M, Schad LR, Wald LL, Guérin B | title = Investigating cardiac stimulation limits of MRI gradient coils using electromagnetic and electrophysiological simulations in human and canine body models | journal = Magnetic Resonance in Medicine | volume = 85 | issue = 2 | pages = 1047–1061 | date = February 2021 | pmid = 32812280 | pmc = 7722025 | doi = 10.1002/mrm.28472 }}</ref>

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MRI uses powerful magnets and can therefore cause [[Ferromagnetism|magnetic materials]] to move at great speeds, posing a projectile risk, and may cause fatal accidents.<ref>{{cite news |author=[[Agence France-Presse]] |url=https://www.theguardian.com/world/2018/jan/30/mri-scanner-india-death |title=Man dies after being sucked into MRI scanner at Indian hospital |work=The Guardian |date=30 January 2018}}</ref> However, as millions of MRIs are performed globally each year,<ref>{{cite web |url=https://international.commonwealthfund.org/stats/mri_exams/ |title=Magnetic Resonance Imaging (MRI) Exams per 1,000 Population, 2014 |publisher=[[OECD]] |date=2016}}</ref> fatalities are extremely rare.<ref>{{cite journal | vauthors = Mansouri M, Aran S, Harvey HB, Shaqdan KW, Abujudeh HH | title = Rates of safety incident reporting in MRI in a large academic medical center | journal = Journal of Magnetic Resonance Imaging | volume = 43 | issue = 4 | pages = 998–1007 | date = April 2016 | pmid = 26483127 | doi = 10.1002/jmri.25055 | publisher = [[John Wiley and Sons]] | s2cid = 25245904 | doi-access = free }}</ref>

MRI machines can produce loud noise, up to 120 [[A-weighted|dB(A)]].<ref>{{Cite journal |last1=Price |first1=D. L. |last2=De Wilde |first2=J. P. |last3=Papadaki |first3=A. M. |last4=Curran |first4=J. S. |last5=Kitney |first5=R. I. |date=February 2001 |title=Investigation of acoustic noise on 15 MRI scanners from 0.2 T to 3 T |journal=Journal of Magnetic Resonance Imaging  |volume=13 |issue=2 |pages=288–293 |doi=10.1002/1522-2586(200102)13:2<288::aid-jmri1041>3.0.co;2-p |issn=1053-1807 |pmid=11169836|s2cid=20684100 |doi-access=free }}</ref> This can cause [[hearing loss]], [[tinnitus]] and [[hyperacusis]], so appropriate [[Hearing protection device|hearing protection]] is essential for anyone inside the MRI scanner room during the examination.

===Overuse===
{{See also |Overdiagnosis}}

Medical societies issue guidelines for when physicians should use MRI on patients and recommend against overuse. MRI can detect health problems or confirm a diagnosis, but medical societies often recommend that MRI not be the first procedure for creating a plan to diagnose or manage a patient's complaint. A common case is to use MRI to seek a cause of [[low back pain]]; the [[American College of Physicians]], for example, recommends against imaging (including MRI) as unlikely to result in a positive outcome for the patient.<ref name="ACPfive">{{cite journal |author1=Consumer Reports |author2=American College of Physicians |author1-link=Consumer Reports |author2-link=American College of Physicians |others=presented by [[ABIM Foundation]] |title=Five Things Physicians and Patients Should Question |journal=Choosing Wisely |url=http://choosingwisely.org/wp-content/uploads/2012/04/5things_12_factsheet_Amer_College_Phys.pdf |access-date=August 14, 2012 |url-status=dead |archive-url=https://web.archive.org/web/20120624075449/http://choosingwisely.org/wp-content/uploads/2012/04/5things_12_factsheet_Amer_College_Phys.pdf |archive-date=June 24, 2012 }}</ref><ref name="backimage">{{cite journal |author1=Consumer Reports |author2=American College of Physicians |author1-link=Consumer Reports |author2-link=American College of Physicians |date=April 2012 |title=Imaging tests for lower-back pain: Why you probably don't need them |journal=High Value Care |url=http://consumerhealthchoices.org/wp-content/uploads/2012/04/High-Value-Care-Back-Pain-ACP.pdf | archive-url=https://web.archive.org/web/20130115221844/http://consumerhealthchoices.org/wp-content/uploads/2012/04/High-Value-Care-Back-Pain-ACP.pdf | archive-date=15 January 2013 | url-status=dead |access-date=August 14, 2012}}</ref>