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Beyond X-ray

April 01, 2002|BY KEVIN CLAPP

This is the third in a monthly series exploring the diagnostic options open to local patients. Last month: Magnetic resonance imaging (MRI).

kevinc@herald-mail.com

The phrase is common in emergency rooms real and fictional.

On last Thursday's episode of "ER" for instance, characters on the NBC hospital drama were heard uttering versions of it twice.

"Get a full scan just to be safe: head, c-spine, abdomen."

"Head, neck and chest CT."

A descendant of the good old-fashioned X-ray, a computerized tomography (CT) scan uses multiple coils to take several pictures of the body, which can then be used to create a three-dimensional image.

Used to detect cancer, ruptured spleens or hemorrhages, for example, a CT - also called a "cat" scan - test can even be used to detect blood clots in the lungs.

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"You start with a plain X-ray first because that gives you an overview," says Suzanne Buhrman, a certified medical radiographer at Washington County Hospital. "Then you go to a CT scan because it gives a much more in-depth study."

As is the case with other diagnostic apparatus, CT technology is experiencing a renaissance, with patients benefiting from advances.

The first CTs consisted of a single coil taking pictures - usually one centimeter wide - as the body slowly passed through the machine. The trick was keeping patients still so the continuity of the "slices" being taken was not disrupted.

Advances have led to CTs consisting of several more coils. The result is more spirals taking pictures, leading to better image clarity taken in a fraction of the time required in years past.

Fifteen years ago, a head CT might take 20 minutes to complete. Now an image is completed in five. An abdominal CT might last 40 minutes then; it takes six to seven minutes now.

Using a machine with several spirals also provides more information for physicians to analyze, leading to better scans and hopefully a more complete diagnosis.

"You don't have to worry about range of motion so much," says Dr. Paul Marinelli, chief of the radiology department at Washington County Hospital. The drastic differences in scan times can be traced back to improved hardware and software.

"You figure what computer you had on your desk 10 years ago versus now," Marinelli says. "It's just like buying your computer. As soon as you go home, there will be new technology."

In the coming months, Washington County Hospital will have a multi-slice CT scanner at its disposal for patients. Robinwood Diagnostic Imaging Services, at Robinwood Medical Center, also has a multi-slice scanner. Buhrman figures CT usage is split between emergency room patients and others requiring a scan.

The only holdup, according to Marinelli, is the time it takes for information from a scan to be processed. A head CT may take three minutes to complete, but it still takes 10 to 15 minutes for the digitized information to assemble on a computer screen so physicians can analyze it.

Among the challenges for doctors and technicians is setting the record straight for new patients who confuse CTs and MRIs, which use the long, tube-like tunnel to diagnose soft tissue problems.

In comparison, CT machines are like donuts, not cylinders; patients pass through them without having to worry about claustrophobia.

"It is fearful for them, until we explain things to them," Buhrman says. "And then the test is over and most patients say that wasn't as bad as they thought."

For Gail Croft, undergoing CTs are old hat, having experienced them eight times since April 2000.

"The very very first CT scan I had I was scared because I didn't know what to expect," says Croft, who is also a patient advocate in the Washington County Hospital emergency department.

But unlike MRIs, there are few times when patients become claustrophobic, and there is none of the loud sounds typical of an MRI. Another difference between the two is that while a CT scan takes place, no one else is in the room with patients. Radiographers leave the room so that they are not exposed to radition from the machine.

Patients can communicate with technicians in an adjoining room through microphones and speakers in the scanner.

Given two large bottles of contrast to drink, plus an intravenous solution, Croft, a cervical and liver cancer survivor, says her initial CT experience gave her pause.

Sometimes, but not always, a dye is injected into patients. Scans of the feet, ankles, wrists or shoulders, Buhrman says, require no dye. What dye helps detect are aneurysms in the brain or abdomen, blood clots in the lung, or tumors.

Accustomed to the process now, Croft says what she dislikes most is not the scan, but the preparation and waiting on either side of it.

"Because I'm a cancer patient, it might be more nerve-wracking," she says. "Waiting for results, for me, is a little bit disconcerting, and not knowing what they are going to be."

Like other diagnostic specialties, Buhrman must put in significant work to remain current on technology. Re-certification takes place every few years and requires ongoing continuing education.

But the bottom line, she says, is that the procedure provides a measure of comfort and speed for diagnoses needed in a hurry.

"It takes less time to scan the patient," Buhrman says, "than to get them on and off the table."

Next month: Positron Emission Tomography (PET) scans

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