Aug. 1, 2001 -- Despite the horrific MRI accident that caused the death of 6-year-old Michael Colombini earlier this week in Valhalla, N.Y., many medical experts reiterate that the use of the imaging test is safe when used appropriately.
Colombini was undergoing an MRI, or magnetic resonance imaging, at Westchester County Medical Center last Friday when an oxygen canister was turned into a guided missile by the powerful MRI magnet. The canister was drawn into the magnet core while the boy was in the machine. The result was a fatal blow to the child's head. He died on Sunday.
Frank Shellock, MD, an MRI safety expert who has been tracking MRI-related accidents for 16 years tells WebMD that this is the first death caused by an MRI projectile, and that any kind of MRI accident is "relatively rare."
MRIs have been used regularly by doctors since "1982, and it is estimated that about 10 million MRI imaging studies are done in the United States each year," says Shellock, who is a clinical professor of radiology at the University of Southern California.
The imaging machines are very popular because they use powerful electromagnets -- not radiation -- plus computers and radiowaves to create clear and detailed images of the brain and other organs. While accidents involving the magnetized machines are rare, they do happen.
Gregory Chaljub, MD, an associate professor of radiology at the University of Texas Medical Branch in Galveston, says that he and his colleagues know of five instances in which oxygen canisters became dangerous projectiles in MRIs. "If we found [the accidents] in these two institutions, I have to guess that accidents happen elsewhere, too," Chaljub tells WebMD.
In only one of those incidents, all of which are described in a study published in the July issue of the American Journal of Roentgenology, one patient was injured. That patient, a 60-year-old man, sustained fractures to his face when an oxygen canister became wedged in the machine pressing against his head. The man later sued the hospital and was awarded $100,000 in damages.
Chaljub says that MRI suites typically post large warning signs telling of the dangers of metal objects near the machine. The powerful magnets used by MRIs "are on all the time so it is not a question of flipping the magnet on and off. Anytime an object comes into the magnet's field it can become dangerous."
The nurse who carried the oxygen canister into the room where Colombini was being scanned mistakenly believed the canister was made of a nonmagnetic material, like aluminum. Chaljub says that accidents often happen when nonmagnetic and magnetic canisters get mixed up, and he recommends putting special markings on aluminum canisters to indicate that they are safe. He also recommends the use of security entrance systems -- such as the use of special computer codes to unlock the doors to MRI suites.
Shellock and Chaljub both say that implants in the body pose a greater danger for MRI accidents than do potential projectiles. For example, Chaljub says that a woman who had an aneurysm clip in her brain died after undergoing an MRI and "a welder who had a piece of metal imbedded in his eye was blinded in that eye."
"The real problem is implants, pacemakers, or pins [in joints] that can get dislodged by the pull or the magnet or monitoring devices that heat up and burn the patient," says Shellock.
Mark Golden, a public relations consultant with Newman Communications in Boston, Mass., knows first-hand about the risks associated with MRIs. Golden has ongoing low-back pain and three years ago he was scheduled for an MRI evaluation. "They asked me if I ever had any broken bones or if I had had heart surgery," Golden tells WebMD. "But their questions never went above the neck," says Golden, who has a shunt in his brain.
But at the last minute Golden says that he backed out of the MRI because "I have claustrophobia, and I just couldn't do it."
About six months ago he found himself again scheduled for an MRI because of continuing back problems. He decided to grit his teeth and try to overcome his claustrophobia. "But first they asked me some questions, including one about brain surgery. When I told them I had a shunt, they said no MRI for me," says Golden. He says he asked the MRI technicians what would happen to him if he underwent MRI scanning and "they said the magnet would heat up my shunt and possibly explode my head."
Golden says he thinks the technicians were exaggerating, but he has no desire to test them. "I got a simple CT-scan and that answered the questions about my back," he says.
Chaljub says that type of careful questioning that Golden had at his second MRI appointment should be routine procedure at all imaging centers.