Watching the directives : scientific advice on the EU Physical Agents (Electromagnetic Fields) Directive : fourth report of session 2005-06 : report, together with formal minutes, oral and written evidence / House of Commons, Science and Technology Committee.

  • Great Britain. Parliament. House of Commons. Select Committee on Science and Technology.
Date:
2006
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Licence: Open Government Licence

Credit: Watching the directives : scientific advice on the EU Physical Agents (Electromagnetic Fields) Directive : fourth report of session 2005-06 : report, together with formal minutes, oral and written evidence / House of Commons, Science and Technology Committee. Source: Wellcome Collection.

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    2 Background Current use of MRI 4. MRI scanners have been in increasing use throughout Europe and the rest of the world over the last 20 years. They provide a powerful tool for use in diagnosis, treatment and research, and have been widely recognised as the most significant development in medical imaging since the X-ray machine. The scanners provide well-defined images of internal organs of the body, which can be used for diagnostic purposes and also for guiding invasive surgery and other interventional procedures. MRI involves non-ionising radiation. As such, it is, in principle, a safer modality than those that use X-rays, which are ionising radiation. Ionising radiation has well established adverse health effects and its use is governed by exposure limits agreed at EU level.* MRI scanners are also more expensive than X-ray machines, both in terms of the costs of manufacture and of usage. Most current scanners operate at a level of 0.5—1.5 tesla (T),* but new, more powerful MRI scanners capable of producing higher resolution images are being developed and manufactured for use in the UK and elsewhere. For example, the MRC is funding a number of 3 T whole body scanners dedicated to research and a new 7 T machine being installed at Nottingham University is one of only two such facilities in Europe.” MRI is beginning to be used at several UK hospitals instead of X-ray for interventional procedures.® Such usage is likely to increase. The NHS recently purchased 100 new MRI scanners, at nearly £1 million apiece, as part of its Cancer Plan, making the UK a leader in MRI usage as well as research.’ The extent to which use of these new machines will be affected by the limits imposed by the Directive is a matter of current debate. If, as has been suggested, usage of the machines will be affected by the Directive, its impact would be particularly keenly felt in the UK. Box 1: Definition Magnetic Resonance Imaging (MRI) is a medical imaging technique that uses magnetic fields and radio waves to produce detailed images of the body. e Static magnetic field; e Time-varying magnetic fields in the order of 100-1000 Hertz (Hz); and e Radiofrequency (RF) fields in the order of 10-100 MHz). 3 Q851; X-ray exposure limits in the UK are governed by the lonising Radiation (Medical Exposure) Regulations 2000, which implement the European Directive 97/43/Euratom (The Medical Exposures Directive). 4 The tesla is the unit of magnetic flux density. It is a unit to define the intensity (density) of a magnetic field. by LEN StF (OIE: 6 Ev41 7 As above