In October 2005, the ECRI (formerly Emergency Care Research Institute),
a health services research agency in Plymouth Meeting, PA, released an
update to its 2001 guidance article on MRI safety. ECRI's article, "What's
New in MR Safety: The Latest on the Safe Use of Equipment in the Magnetic
Resonance Environment," addresses a number of patient safety issues
that have grown out of technology and operational changes that occurred
in 2005 (Health Devices, October 2005, Vol. 34:10, pp. 333-349).
One of the principal focuses of the guidance article is on the new "MR
Safe" language approved by ASTM International, which is expected
to be adopted by the U.S. Food and Drug Administration soon. The greatest
confusion in the transition from the old "MR Safe" to the new
"MR Safe" is that the two standards use the exact same term
to mean profoundly different things.
The old term meant that an object or device was safe, as long as it was
used in accordance with the limitations set by the manufacturer for exposure
to gradients, field strength, or induced current. The new term means that
an object is safe under all magnetic or radiofrequency (RF) conditions.
Additional information on the vocabulary change is available in "The
new 'MR Safe': Language changes for the FDA."
ECRI's article goes to great lengths to describe the differences, and
also offers guidance and warnings to advise facilities on making the transition
from one set of standards and terms to the newer versions. Among the recommendations
offered by the article, all devices that bear the old "MR Safe"
or "MR Compatible" designations should be presumed to be "MR
Conditional" in the new standard. And until a facility has completely
embraced the new standards and markings, nothing with an "MR Safe"
label should be assumed to be the new MR Safe unless specific product
compliance is known for that piece of equipment.
In related points in the guidance article, ECRI addressed the development
of ferromagnetic detection systems and accidents in the MRI suite.
Although ECRI deferred from making specific statements
countermanding an earlier recommendation against the use of metal detectors
and support of the use of ferromagnetic detection, the article was very
encouraging about the initial test data from Dr. Emanuel Kanal and the
University of Pittsburgh Medical Center in Pennsylvania.
"These detectors at least have the potential to reduce the risk of
patient injury and damage to equipment, as well as to reduce MR downtime
that could occur in the event of an incident," the ECRI wrote.
The clear implication, if Kanal's results are reproducible, is that ECRI
will consider endorsing ferromagnetic detection systems to enhance patient
screening and safety.
Parallel to the section on ferromagnetic detection was a revealing survey
which indicated that, of those facilities that had experienced medical-device-related
incidents, more facilities reported missile or projectile accidents than
patient burns, biostimulation device interference, and other incidents
combined!
The ECRI survey, even though it is from a sample of only 70 respondents,
echoes recent data on near misses from the State of Pennsylvania Patient
Safety Authority. In that report, projectile incidents or near misses
were at least as frequent as other MRI patient safety concerns. These
new data sources each lend a small light to a growing illumination of
dramatic gaps in the current reporting of MRI accidents (missile accidents
in particular) to the FDA.
The ECRI article, although an excellent piece on explaining the new standard
and facilitating the transition to it, does not identify the ASTM and
FDA bias in the development of this new standard for classifying the safety
of objects in the MRI suite.
ASTM and the FDA are primarily interested in safety as it applies to regulated
medical devices. Safety issues surrounding nonregulated items, even if
they directly impact the safety of patients inside the bore of an MRI
system, have not received a level of attention comparable to that of pacemakers,
ventilators, or other regulated devices.
Sandbags, floor mops, ladders, and chairs, all devices that are brought
into MRI suites on a regular basis, are being shoehorned into a clinical
device standard. The ferromagnetic projectile risks, which data suggest
are one of -- if not the -- most common patient safety threat, are not
specifically addressed in the standard.
To anyone concerned with MRI patient safety and suite operation, the October
2005 ECRI guidance article is very useful and deserves a place in your
library of safety reference materials. Although MRI safety is too broad
of an issue to be bounded by the ECRI article, when used in concert with
other resources including the "ACR White Paper on MR Safety"
and the MRI Newsletter, this piece can help to inform improved patient
safety and care.
By Tobias Gilk
AuntMinnie.com contributing writer
March 28, 2006