Handheld ultrasound puts diagnostics within reach
By Susan FitzGerald
David Hellmann, MACP, thinks it's time for doctors to put some new gadgets in their little black bags, and he suggests starting with a handheld ultrasound machine.
"There's a lot of evidence that the physical exam can miss many findings," said Dr. Hellmann, chairman of medicine at Johns Hopkins Bayview Medical Center in Baltimore. Having ultrasound at the ready "could add value for the patient."
While ultrasound machines are still mostly in hospitals and imaging centers, Dr. Hellmann and others believe portable models will one day be common in primary care offices. The machine, the size of a laptop computer, can check for aortic aneurysms, pericardial fluid, heart valve problems and gallstones, among other problems. It also can screen for cardiovascular disease and provide visual guidance for inserting venous lines.
Doctors who use the machines say they allow them to arrive more quickly at a diagnosis and create a treatment plan, rather than having to refer a patient for an ultrasound and wait for word from the radiologist.
A case in point: John Postley, FACP, a Manhattan internist, used handheld ultrasound after he felt something suspicious in the abdomen of an elderly patient who had come in for a check up following knee surgery.
"I whipped out the ultrasound and there was this 6-cm ballooning aortic aneurysm and he got operated on two days later," said Dr. Postley, an assistant clinical professor of medicine at Columbia University.
Dr. Postley, who gets loaned machines and has received speaker fees and a research grant from SonoSite, a maker of hand-carried ultrasound machines, said he uses it during routine physicals. He doesn't accept insurance, except for Medicare, and charges $600 for a physical. He charges $250 for an ultrasound test to check for arterial plaque.
Dr. Postley is researching the potential of office-based ultrasound to detect cardiovascular disease by checking for carotid and femoral plaque and carotid wall thickness.
"The ultrasound is a non-toxic, non-invasive extension of the physical exam," he said. "It gives us the opportunity as internists to see all sorts of things we can't see otherwise."
Obstacles to acceptance
Convenience aside, handheld ultrasound machines are not likely to become fixtures of the typical internist's office in the near future. Several issues need to be addressed first, including:
- Reimbursement. The devices are expensive and most insurance companies don't cover office-base ultrasound exams. A SonoSite hand-carried model for the ambulatory setting, for example, costs $35,000 to $50,000, according to Tom Dugan, SonoSite's senior vice president for marketing and U.S. sales.
- Training. Unlike sonographers and radiologists, most general practitioners are not trained in the technical aspects of doing an exam or interpreting the images. "It's not something that people can just pick up and use," said Arl Van Moore, MD, chairman of the board of chancellors of the American College of Radiology, and a radiologist practicing in Charlotte, N.C. He added that radiology residents do a minimum of six months of training on ultrasound and other technologies such CT and MRI. If ultrasound is not done correctly, he added, you can have "misdiagnoses and delayed diagnoses."
- Risk of overuse. "One of the rightful questions is, 'Is this going to make medical care better by making diagnoses faster and making things more convenient for the patient?'," said Dr. Hellmann. "My hunch is that it would improve care ... but it could also introduce errors, lead to more testing and add costs."
While hand-carried ultrasound machines may not yet be practical for primary care physicians, they already have made inroads in critical care areas such as emergency departments, intensive-care units and some specialty practices. They've been used in natural disasters and in the war in Iraq to triage casualties. SonoSite, in Bothell, Wash., said 30,000 of its hand-carried machines are in use worldwide. The company had $171 million in sales last year.
Anthony Dean, MD, an emergency room doctor at the Hospital of the University of Pennsylvania in Philadelphia, took a portable ultrasound machine tucked inside a backpack when he went to Guatemala in 2005 to care for people affected by mudslides caused by Hurricane Stan.
"It was tremendous," he said. "We used it for two weeks, well over 100 times."
He uses ultrasound frequently in the emergency room—ER residents are trained in the technology—where the technology often circumvents long waits for tests to be done in the radiology suite or other parts of the hospital.
Having ultrasound in the ER isn't just for convenience, though. "In cases of cardiac arrest, massive trauma, collapsed lungs, massive pulmonary emboli, or bleeding aortic aneurysms, there simply isn't time to get a specialist to do the imaging study," Dr. Dean said.
"Today we had a patient come in with unexplained leg swelling and in 15 minutes we found out he had deep vein thrombosis," said Dr. Dean, who directs Penn's emergency ultrasound training program. "We started him on heparin and admitted him."
Detecting heart disease
Much of the research on hand-carried ultrasound is focused on its potential for detecting cardiovascular disease.
"For many people, the first sign of heart disease is that they die suddenly," said James Stein, FACP, director of preventive cardiology at the University of Wisconsin School of Medicine and Public Health. Standard risk assessments, such as the Framingham model, can underestimate the risk of heart disease, he said.
Dr. Stein—who has received research funding from SonoSite and Siemens Medical Solutions, another ultrasound vendor—has been studying whether non-sonographer clinicians can be trained to use ultrasound to measure carotid intima-media thickness.
He co-authored a study October 2006 in the Journal of the American Society of Echocardiography which showed that an internist could be trained to perform carotid exams nearly as well as sonographers. He just completed another study on the use of hand-held ultrasound by non-sonographers in the office setting. Doctors and nurses who did a two-day course, followed by mock scanning until becoming proficient, performed well, said Dr. Stein. He will present the findings at a national meeting later this year.
"It takes significant training," he said. "I don't want people to think they can buy a machine and pick up a probe and do it."
Dr. Stein said doctors were more aggressive with prescribing aspirin and cholesterol medications after they identified carotid wall thickness and plaque. But he added that more research is needed.
"We don't have proof that knowing someone has sub-clinical atherosclerosis improves their long-term outcome, but all signs point to this being a useful test," he said.
"If you're doing handheld ultrasound, you're laying hands on the patient and spending time with the patient."
—David Hellmann, MACP
Dr. Hellmann, at Johns Hopkins, is also interested in the use of hand-hand ultrasound in detecting cardiac problems. He published a study in the September 2005 American Journal of Medicine showing that residents were adept at learning to do some aspects of bedside echocardiography. He said that problems such as left ventricular dysfunction can be missed when a doctor relies solely on the physical exam and sounds heard through a stethoscope.
Dr. Hellmann said there's a concern that giving ultrasound to the internist will depersonalize the doctor-patient relationship, but he suspects the opposite.
"If you're doing handheld ultrasound, you're laying hands on the patient and spending time with the patient," he said. "Some people see the tools in the current physical exam as sacred and say if we replace them we are losing something of the profession. I don't buy that argument because I don't think patients care what we use. They want us to get it right."
John Postley, FACP, a Manhattan internist, is researching the potential of office-based ultrasound to detect cardiovascular disease. Examples of uses in the practice include aortic aneurysms, which are much less common. Data to be presented in June indicates that 45% of an unselected population having screening tests will have significant ultrasonically determined atherosclerosis. But physicians agree that training is needed to use the devices properly and interpret the results correctly.
A large aortic aneurysm is a dramatic but less frequent condition detected by handheld ultrasound units.
An image from a handheld ultrasound reveals a longitudinal carotid plaque, a common condition that is important in picking up asymptomatic disease.
A handheld ultrasound reveals a transverse carotid plaque.
A handheld ultrasound reveals a longitudinal femoral plaque.
A handheld ultrasound reveals a transverse femoral plaque.
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