Commission poised to delay rule that could suffocate MRI use in Europe

MRI practice restrictions introduced this year in Slovakia may spread in April 2008 to all 27 countries in the European Commission, if the EC governing body does not delay a controversial regulation aimed at protecting workers from harmful exposure to electromagnetic fields.

According to informed sources, the European Commission is considering a proposal to delay by four years the deadline for implementing the directive due to mounting evidence from research that the directive would have a negative effect on MR practice. A moratorium would also allow more time for the completion of an EC-sponsored study of the regulation.

The scientific and medical community has noted that the limits will severely curtail MRI in clinical practice and research. Experts claim that scanner-side care of patients will be barred, interventional MRI will be outlawed, and routine maintenance of MRI systems will be severely impeded.

Some of those fears appear to have been realized in Slovakia, where the government jumped ahead of other EC members to incorporate the Physical Agents (Electromagnetic Fields) Directive 2004/40/EC into national law. One major MRI vendor has instructed workers at its Slovakian subsidiary not to stand within a meter of an MRI system during scanning. Engineers have also been told not to move faster than 0.15 ms^-1 when they are working on magnets.

Instructions to move in slow motion are based on an understanding about differences in the perceived risks from standing and moving in a static magnetic field. The directive places no limit on human exposure to static fields, but moving rapidly in a static field is thought to be equivalent to being stationery in a time-varying magnetic field, which is subject to regulation.

"It would be funny if it weren't so tragic. Clearly it makes servicing of the equipment completely untenable," said Dr. Stephen Keevil, head of MR physics at Guy's and St. Thomas's NHS Foundation Trust in London. "Years ago, when this debate started, we all joked: 'We'll have to impose speed limits on people and they'll be walking in slow motion, like men on the moon.' Now it has actually happened."

A June 2007 investigation, commissioned and published by the U.K. Health and Safety Executive and available online, raised additional concerns. Stuart Crozier, Ph.D., director of biomedical engineering at the University of Queensland in Brisbane, Australia, found that anyone standing within a meter of an operating MR scanner would be exposed to enough short-term electromagnetic radiation to violate the regulation.

Results from the EC's own research, based on experimental data acquired at four European MRI facilities, are expected in January 2008. But if the commissioners wait for these findings before taking action, it will be too late to prevent the directive's EU-wide implementation. Insiders now predict that measures to delay enforcement will begin in the next few weeks.

"The question: 'Is there a problem with these exposure limits?' has already been answered by the Crozier study. That in itself is enough to justify the delay, and that is what [the commissioners] appear to be agreeing to do," Keevil said.

The proposed four-year postponement would give commissioners two years to redraft the directive and another two years to gain approval for any changes. Revised recommendations on exposure limits from the International Commission on Non-Ionizing Radiation Protection (ICNIRP) are not expected before the end of 2008.

Lobbying groups, including the Alliance for MRI, have campaigned for MRI to be excluded from the directive altogether, but relief is by no means guaranteed.

"We don't know what the recommendations of ICNIRP might be," said Dr. Gabriel Krestin, radiology chair at Erasmus University in Rotterdam, the Netherlands. "It is still possible that the exposure thresholds they recommend will set some limitations on the use of MRI in certain circumstances, such as interventional MRI or imaging under anesthesia."

An extended period of uncertainty could also stall sales of high-field systems. Revised legislation may simply contain new limits that would make working at 3T or higher problematic.

"We are already hearing that some hospitals and universities that were planning to put in high-field systems are thinking twice. In four years' time, they may find that they have to stop using them," Keevil said.

For more information from the Diagnostic Imaging archives:

Europeans scramble to thwart threshold law for electromagnetics

ESR must flex its muscles to get heard in Brussels

Regulators pose potential threat to high-field MR