A blemish in diagnostic imaging
Al Musella's Comments: (This is his personal views and are not necessarily the views of the Musella Foundation!)
Posted on: 07/18/2004
A blemish in diagnostic imaging
Posted on Sun, Jul. 18, 2004
As the use of the techniques becomes more common, physicians looking for one problem are accidentally finding others. But determining whether suspicious spots are harmless or deadly is a challenge.
BY MARIE MCCULLOUGH
Knight Ridder News Service
When Lisa Shields felt short of breath in December, she worried that she had developed a blood clot in her lungs, a problem that runs in her family.
Two CT scans and an ultrasound test found no dangerous clots in her body. But her thymus — a little gland behind the breastbone that makes white blood cells and shrinks by adolescence — looked a bit large, a possible sign of a nerve-muscle disorder.
Since then, the 32-year-old from Philadelphia has had additional CTs, a brain MRI, a PET scan, and other high-tech tests. Although doctors have ruled out neuromuscular diseases, they still don't know whether she has a thymus tumor that should be removed, or a blood cancer called lymphoma that should be treated with chemotherapy.
Or just a harmless bit of leftover thymus gland.
"So (in) one month … I'm having my chest cracked open," Shields said matter-of-factly. "At this point, I just have this gut feeling that it needs to come out."
Thanks to an explosion in diagnostic imaging over the last two decades, physicians looking for one thing are accidentally finding lots of others. They're also supplementing standard X-rays with the angles, cross-sections and three-dimensional views of the latest scans.
The problem is, determining whether suspicious spots are harmless or threatening is still a challenge. Even detailed pictures can be ambiguous, and each imaging method poses its own set of interpretive pitfalls.
The results are more and more diagnostic scans, more exploratory surgeries, more ethical dilemmas and greater expense.
No one can say whether more disease and deaths are being prevented, but clearly, most abnormalities turn out to be trivial. "There are many blemishes on our skin," said Marvin Lipman, a professor at New York University Medical College who has written about the downside of the imaging explosion. "We never knew how many blemishes we have on our internal organs until we started looking. In this litigious age, every time you find one of these things, you need to follow up."
Liability concerns are combining with innovations, advertising aimed at patients and an aging population to make radiology an all-important field. Just since 2000, U.S. spending on diagnostic imaging has climbed from $75 billion to almost $100 billion, estimates Booz Allen Hamilton, a technology- consulting firm. MRIs alone accounted for 22 million scans in 2002, up 22 percent in a year.
The problem of running across an abnormality while checking for something else — what doctors call "incidental findings" — is as old as the art of healing. But machines that peer deep inside the body are revealing more than physicians' hands, stethoscopes or blood tests ever could.
One revelation is that the abnormal may be the norm. Studies of incidental findings show:
• MRIs of the brain used in researching sensory and mental activity revealed brain abnormalities, mostly of blood vessels or nerves, in almost half of 151 healthy adult volunteers in a Stanford University study.
• MRI scans suggest a quarter of young adults have knee abnormalities, and half have lumbar disk bulges, despite the absence of pain. One in every 10 people may have pituitary tumors.
• Ultrasound indicates up to 67 percent of people have thyroid nodules.
• Ultrafast CT scans of the colon — the new non-invasive "virtual colonoscopy" — often turn up lymph-node abnormalities, aortic aneurysms, gall stones, liver and kidney masses and hiatal hernias. A Swedish study found 130 such abnormalities in 111 virtual colonoscopy patients. A British study found 171 abnormalities in 103 colonoscopy patients.
Yet diagnostic imaging can be a godsend. Barbara Ayes of Cherry Hill, N.J., had a mammogram that did not reveal her lobular breast cancer, which often stays hidden on X-rays. If her physician had not ordered an MRI, her cancer might not have been caught early.
"I know insurance companies are going to hate me, but I think MRIs are important for high-risk women like me," said Ayes, 56, who has a family history of breast cancer.
The diagnostic imaging explosion is increasing the likelihood of overdiagnosis and overtreatment, experts agree. Ironically, these very problems are why experts decry walk-in "health scan centers" that do whole-body CTs for a fee.
Another effect: New digital information systems that help radiologists manage the avalanche of images increase incidental findings. These picture-archiving systems, or PACS, include the inferior images, used to plan the rest of the exam, that formerly were discarded without review.
"We always look at everything that's available," said William Morrison, a radiologist at Thomas Jefferson University Hospital in Philadelphia.
How many accidentally discovered abnormalities turn out to be serious?
Of 202 that Morrison found at Jefferson, 3 percent were cancers. Of 71 found on brain MRIs at Stanford, 4 percent required urgent follow-up. Of 192 thyroid nodules in a Korean study, 29 percent were malignant.
While the chances of serious disease are relatively small, clinicians dare not be blase.
"Liability issues make it emotionally and financially costly to miss a cancer," said Mitch Schnall, a University of Pennsylvania radiologist and expert on MRIs of the breast. "The physician can be asked, 'Why didn't you do this test?' even if insurance won't pay for it."
do that without considering the cost."
For patients, incidental findings open a Pandora's box of fear and uncertainty, as well as questions about costs.
Rocky Gilbert discovered that last summer. After decades of running, the 56-year-old Philadelphia resident was diagnosed with a shattered disk in her back. Amid the X-rays, ultrasounds and MRIs — and excruciating pain — she learned she had a mass, probably just a cyst, on her kidneys.
"I was scared to death when they told me that," Gilbert recalled. "I said, 'What else is falling apart? Will it interfere with my back surgery?' "
She still doesn't know for certain what is on her kidney, but her surgeon has reassured her that monitoring it is sufficient.
Most patients want definitive answers, no matter what it takes to get them.
Jill Smiley, 40, a Philadelphia pharmaceutical technician with no risk factors for breast cancer, was stunned 18 months ago when her first mammogram revealed calcium deposits in her left breast — a classic sign of early-stage disease. A breast MRI could not rule out a malignancy, so she decided to have an MRI-guided biopsy.
There was no cancer.
"I'm glad I went through it, because I'd rather know than not know," she said. "I kept thinking, 'People who go through chemotherapy go through more pain than this, so I just have to grit my teeth."'
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