MONTREAL -- A U.S. company that's been scanning the internal organs of Canadians for years says it attracts cross-border clients with the pitch it can detect hidden health risks before it's too late.

"A BODY SCAN Can Save Your Life!" reads the bold headline on Canadian newspaper advertisements for Ultra Life Inc., a firm offering bargain-basement ultrasound screenings on about a dozen different parts of the human anatomy.

The company's owner says the ads have been drawing Canadians to temporary clinics in U.S. border towns for at least a decade.

Ultra Life's warning raises questions: Are precautionary ultrasounds effective prevention tools, or largely unnecessary tests with the potential for more harm than good?

Some physicians recommend a cautious approach to unprescribed ultrasounds because results can be wrong, such as identifying a medical problem that doesn't exist. Errors like this can unnecessarily whip up patient anxiety and lead to even more-invasive scans and treatments.

Doctors also warn that screenings may miss an actual health issue, giving patients a false sense of security and perhaps leading them to ignore symptoms.

The California-based company, however, insists its accuracy rate is roughly the same as those in clinics and hospitals.

Ultra Life owner Warren Green says his pan-U.S. touring operation, which occasionally sets up temporary clinics in hotels along the border, fills an important void in the health system.

"We're not preying on anybody's fear," Green said when asked about criticism directed at his trade.

"We're picking up things that the regular doctors down here and in Canada aren't really interested in until (the patients) get the symptoms ... This is prevention or elective testing. People who just want to see how they read out on everything."

A few times per year, one of the company's three mobile clinics sets up shop within a two-hour drive of Canadian cities -- across the border from provinces like New Brunswick, Ontario and British Columbia. Last month, one of them stopped in Plattsburgh, N.Y., about 100 kilometres south of Montreal.

On its menu, Ultra Life services include pancreatic, gall bladder and stroke scans for US$60 each, heart scans for US$150 or the "cost-saving" full-body-scan package for US$500.

Green said the ultrasounds are conducted by certified technologists, with test results analyzed by medical doctors who send their reports and images directly to clients.

He said the screenings have detected cancers and other medical abnormalities deep inside patients, though he declined to share specifics of past success stories from his 29 years in the business.

"I don't think (client) testimonials are a good milestone for advertising or trying to scare people," Green said.

"Yes, we find a lot of disease, all the time."

He would not say how many Canadians his service treats every year, though he notes the company gets an "excellent response" whenever it advertises in Canada.

Overall, Green insists demand for the screenings, which do not need physician requisitions, has been on the rise.

He estimates his business has increased by 50 per cent since it started in 1985, even with the addition of six or seven competing operation in the United States.

In the medical community, however, businesses like Ultra Life have raised concerns.

Health Canada recommends people only seek diagnostic tests following a clinical evaluation and a referral from a physician.

The department describes an ultrasound as a powerful, non-invasive medical tool that provides real-time imaging of a fetus, internal organs, major veins and arteries. It warns the scans can cause "destructive heating" or interaction effects with microscopic bubbles in the body.

Some experts say while the ultrasounds themselves are quite harmless, test results can lead to problems.

Dr. Benoit Gallix, chairman of the McGill University Health Centre's radiology department, said there's a risk test results could find medical issues that don't really exist.

"The probability of finding something (harmful) is really rare and there is more probability to find something benign," said Gallix, who added that ultrasounds are poor predictors of budding problems, like tumours.

He said he's seen patients unnecessarily stressed after incorrect results of a precautionary ultrasound told them they had a problem, a situation that forced him to send them for a riskier scan for reassurance.

In other cases, encouraging test results could provide patients with a false sense of security, he said. For example, Gallix said, a patient could disregard chest pains because he was given a clean bill of health after an ultrasound.

Gallix did not dismiss preventive ultrasounds altogether, saying it's possible, in rare cases, they could uncover a health hazard.

"Probably for one patient out of 1,000, it will be very helpful," he said. "The problem is, what about the 999?

"We always think about the balance between potential risk and potential benefit, and my feeling is these kinds of offers have more potential risk than potential benefits."

It would be better, he added, for people to only seek preventive scans on a physician's recommendation.

Gallix said medical research has shown that preventive screening is likely a good tool for finding breast cancer, while the effectiveness of precautionary imaging for identifying colon and lung cancer is still under evaluation.

"That's it," he said. "All the other screenings are more marketing."

Private Canadian clinics also offer preventive ultrasounds.

But in Quebec, for example, the law states patients must have a signed referral from a physician, said a senior director at health-care company Medisys.

Luisa Terrigno said Medisys doctors will provide preventive-ultrasound requisitions. She said most physicians in the public system focus on treating symptoms.

"You'd be surprised as to what you find sometimes, pathology-wise," said Terrigno, who added she's heard of scans finding problems like renal cancer and cystic lesions in the ovaries.

She said any type of imaging could miss potential problems or mistakenly detect an issue that doesn't exist. To help manage these situations, Terrigno said the referring physician receives the report and decides how to proceed.

The cost, she added, is often covered up to 80 per cent by private insurance. The ultrasounds at Medisys typically range between $125 and $300, which Terrigno said isn't expensive even if a patient foots the entire bill.

"It's not an extreme price," she said in a phone interview from the company's head office in Montreal.

"Some people spend more than that on their shoes."