Hospitals across North America could be failing to diagnose small tumours in obese patients who either can’t fit into an X-ray scanner or have fatty tissue so dense the machine can’t penetrate it, a new study suggests.
The study, published in the August issue of the journal Radiology, found a growing number of patients are too large to fit into the scanner. In other cases, the X-rays have been fuzzy or imprecise because dense fat blocked the machine’s beams.
“There are things that you can miss because the X-ray beams are just not able to penetrate deep enough,” said study author Raul Uppot, a radiologist at Massachusetts General Hospital in Boston.
In some cases, the quality can be so poor that doctors could miss small lung, abdominal and liver tumours, Uppot said.
“We really have to address this issue,” he said.
“Canadians, Americans . . . should all realize that this is another problem they will have if they are obese. When they walk into the hospital, they may not be getting the most adequate care.”
Canadian hospitals are also grappling with the difficulties of diagnosing an increasing number of obese patients.
Stewart McNeil, patient equipment co-ordinator at Hamilton Health Sciences, said older equipment wasn’t designed to accommodate larger patients. He said older MRI scanners are often 46 inches wide.
“People are getting bigger and bigger,” said McNeil. “All hospitals are struggling with it.”
McNeil pointed out that the hospital can rent over-sized equipment when it’s called for, but noted that patients who are very obese are sometimes sent to nearby veterinary colleges.
“The MRI and X-ray machines there are designed for horses,” he said. “How would you feel?”
Ian Doris, board member of the Ontario Association of Radiologists, said sometimes just lifting an unconscious obese patient on to a scanner can take up to eight people.
Many older scanners also can’t support more than 400 pounds of weight, while in other cases, a patient’s sheer girth can touch the sides of the scanner, making it difficult to get a clear image.
It’s a particular problem with ultrasounds and detecting liver disease, said Doris, who noted the importance of ensuring that such patients are treated with the dignity they deserve.
“These people aren’t this way because they sit around eating Tim Hortons all day,” said Doris, a radiologist with Hamilton General Hospital. “It is recognized as an illness.”
While patients are expected to take responsibility for their own health, doctors say hospitals should also be updating their equipment to reflect the increasing weight of their patients.
They say hospitals have difficulty accommodating obese people outside the X-ray room as well — from finding stretchers and beds that are wide enough to providing plus-sized commodes.
Hospitals are supposed to replace their equipment every 10 years — a guideline that’s often ignored when the equipment is still functioning properly, said Robin Hesler, CEO of the Ontario Association of Medical Radiation Technologists.
In the meantime, Hesler said obese patients may be exposed to higher levels of radiation in some scans because more is needed to produce an image.
“This is a potential issue down the road,” Hesler said, adding obesity is on the rise. “This is a growing issue.”
Statistics Canada shows the nation’s obesity rate has almost doubled in the last 20 years — jumping from 13 per cent in 1978 to 23 per cent in 2004. The agency said obese adults are more likely to suffer health problems such as cardiovascular disease, high blood pressure, diabetes, some cancers and gall bladder disease.
