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Making waves

This is the fifth in an occasional series on medical diagnostics.

This is the fifth in an occasional series on medical diagnostics.

July 08, 2002|by KEVIN CLAPP

kevinc@herald-mail.com

Rachel Green, dressed in a hospital gown, was crying as one-time boyfriend Ross Gellar stood beside her squeezing her hand.

The cause of her upset? Her inability to see her unborn child from an ultrasound monitor.

On the NBC sitcom "Friends," this scene evoked a wave of laughter. But like all good comedy it was rooted in reality.

"A lot of them," admits Dr. Paul Marinelli, chief of the radiology department at Washington County Hospital, about sonograms, "look like weather maps."

So to the untrained eye, an ultrasound can yield an image that looks like a fuzzy black and white blob, a jiggling Rorschach test at a time when clarity is preferred.

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Luckily, technology is changing all that.

Oh, the amorphous images remain, but they are sharper these days on the more advanced equipment. And they can come in color, with cascades of red and blue spreading across a computer screen depending on direction and speed of blood flow.

But the next wave of the sonogram technology offers the greatest trip - a four-dimensional image that leaves no doubt as to what are fingers and what are toes, and can eliminate the mystery of figuring out whether what you are looking at is a boy or a girl.

"Any layman, pregnant women, can appreciate what their looking at," says Dr. T. Toe Thane, associate radiologist and head of the ultrasound department for Summit Health in Pennsylvania. "Sometimes with 2-D it's hard to tell what you're looking at."

There are other benefits as well, not the least of which is the ability to better see fetal anomalies on 3-D pictures, leaving less chance that hard to distinguish problems are lost amid a blur of images.

Unlike more cumbersome equipment like CT, MRI or PET scanners, ultrasound is relatively sleek, the size of a computer set atop a small cart. New advances include a portable unit with the potential to be used in patient rooms or at community health fairs, and technology that creates four dimensional images that move in real time.

And ultrasound is versatile. Well-known for its use during pregnancy, the test can be used to detect gallstones, blockages in arteries running through the arms or legs, or to examine the uterus or thyroid.

All for a few hundred dollars, a fraction of the cost of other tests.

"Obstetric ultrasound has really done a great service to ultrasound in general," Marinelli says. "(Patients) become real relaxed because it must be safe if they're using it on pregnant women."

Testing time varies depending on what is under examination. A check of the gallbladder may take only five minutes, but scanning arteries in the legs for signs of atherosclerosis could last 45 minutes.

Another benefit of ultrasound comes when physicians are searching for something in the body without much success.

"If I need to biopsy something in a patient, we'll use ultrasound to guide us," he says. "So (using) a portable machine rather than hauling a big monster around can be very beneficial."

Within six months, Marinelli expects to have a 4-D machine - at a price of up to $350,000 - at Diagnostic Imaging Services at Robinwood Medical Center, which already has five machines. There are three ultrasounds at Washington County Hospital, and he hopes to add a portable scanner, costing $25,000, in the future.

In Pennsylvania, Thane says there are two ultrasounds at Waynesboro Hospital; two at Chambersburg Hospital; and five at Summit Health Center in Chambersburg. In the coming months, a 4-D machine will be brought into the health center while two existing machines will be upgraded to create the 4-D images.

At Summit Health, there are 45 to 55 ultrasounds conducted a day, with equal numbers of carotid scans - a picture of the carotid artery in the neck, pregnancy scans of a fetus and gallbladder scans.

"The beauty of ultrasound is, first of all, it's very uninvasive," Thane says. "And secondly it's a non-ionizing test, no radiation at all."

Indeed, this is among the reasons ultrasound is so popular, Marinelli says. Unlike PET or CT scans, no radiation is involved with the test.

Instead, sound waves are transmitted into the body from a transducer - the computer mouse-like object doctors run across the body.

The waves then bounce off organs and return to the transducer, their frequency and speed used to create pictures for doctors to read. The only trick is that the waves don't pass through bone or air, so on a scan those areas are black.

As a result, ultrasound is not a good tool for examining the lungs, which are full of air and encased by the rib cage. Ultrasound is very good, however, at scanning the neck, or organs in the abdominal area.

As with any test, whether CT, MRI or ultrasound, Marinelli cautions against the use of test results in a vacuum. Technology must always be used in tandem with physical examination of patients because while pictures may never lie, they can misrepresent.

"Just because you see something on a picture doesn't mean there's something abnormal," Marinelli says. "Because something normal in one patient is not normal in another. Sometimes it can be a slam dunk but sometimes it can be confusing."

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