Jean Lawrenz wanted to know what was causing her shortness of breath. She worried it was heart disease, which runs in the 71-year-old's family.
Still, she dreaded doing something more invasive like an angiogram, where doctors can view the coronary arteries by pumping dye through a flexible tube guided from the groin area into the heart.
Her cardiologist suggested another option.
Today, technology gives doctors their best view yet of a beating heart without using an invasive procedure. CT coronary angiography allows physicians to quickly view arteries with little discomfort to the patient.
The technology has been around for a few years but is becoming more common in hospitals across the nation. The latest version is the 64-slice CT scanner, although faster and more powerful versions are being tested.
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The equipment produces detailed, three-dimensional images of any organ in an instant. Its value for scanning the heart is that it is so quick that it can grab pictures of a heart between beats - something that hasn't been possible with earlier generations of scanners.
As a result, it holds great promise for diagnosing heart disease without the risks and discomfort of a surgical procedure.
"There are revolutionary things from time-to-time in this field," said Dr. Wallace Radtke, a cardiologist at MeritCare in Fargo. "This is a big one."
Ease of scanning
MeritCare purchased a 64-slice CT and used it for the first time last fall. So far, cardiologists there have tested 50 volunteers and 20 patients.
Innovis in Fargo is currently looking at updating its cardiac CT scanning, said spokeswoman Kris Olson.
Each year, millions of people seek emergency medical care because of chest pain, a common symptom of a heart attack, according to a study published last October in a journal by the American Heart Association. Use of a non-invasive heart scan can help physicians quickly determine who can be discharged and who should be admitted to a hospital.
The ease of the test intrigued Lawrenz. Before the scan, she took medications to slow down her heart beat to about 60 beats per minute. Her blood pressure, oxygen levels and heart beats were monitored. Nurses started an IV for fluids and a contrast dye that would highlight the coronary arteries.
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Lying on a cot, she was moved through the large center hole of a donut-like structure. She drove herself home after the procedure.
"You don't have to involve anyone else and there's no cutting," she said. "That to me is nice."
Unfortunately for Lawrenz, the test proved inconclusive. The first scan showed too much calcium in Lawrenz's arteries to continue the tests. Calcium deposits can skew some of the results, Radtke said.
As a result, not all patients are candidates for the test, he said.
Lawrenz, who lives in Detroit Lakes, Minn., hasn't yet met with her doctor to discuss other options, she said.
The test has worked for most other patients, however, preventing some from having to undergo unnecessary angiograms, Radtke said.
"We look for a narrowing of arteries and if things look normal, you're done," he said.
Preventive tool
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The scan takes multiple pictures, slicing the heart like a loaf of bread. Each slice is about 0.6 millimeters thick or about as wide as a pen line. A computer reassembles the sections, allowing doctors to get two-dimensional or three-dimensional views of the organ.
For a better look, doctors can rotate the pictures or highlight only the blood vessels. They can see bypass grafts and stents placed to prop open a clogged artery. It takes about 15 minutes to gather hundreds of snapshots.
At MeritCare right now, the tool is mostly being used to diagnose coronary heart disease in people who have symptoms. For example, doctors may recommend the test if the patient has an abnormal stress test or has chest pains or breathlessness.
Surgeons also may use it to identify calcium deposits in coronary arteries so they aren't accidentally nicked, which can break off the calcium and cause a stroke, Radtke said.
But in the future, the scan could be used as a preventive tool for heart disease. The test can show the build-up of plaque in arteries before a person shows symptoms. Patients with a family history of heart disease could benefit from such early detection.
"Maybe it would be like a colonoscopy only you'd have a scan to check your arteries every five years or so," Radtke said. "Maybe people would take lifestyle changes more seriously if they saw a lot of plaque."
Readers can reach Forum reporter
Erin Hemme Froslie at (701) 241-5534
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