Health Talk


Electron beam tomography (EBT), a scanning procedure that produces three-dimensional images of organs and arteries, is now being used as a screening tool to detect early signs of cardiovascular disease. Dr. Bekir Melek, assistant professor of medicine at Tulane University Health Sciences Center, discusses the technology with Kandace Power Graves.

Q: How exactly does EBT scanning work?

A: It's like a regular CT scan, but the technique is just a little different. It takes about 10 minutes and there is no discomfort. There is no pain involved. X-ray is used, and multiple slices of images are taken of the area of interest. That allows for a three-dimensional quality (that allows an area to be viewed from every angle). We have a reading room where we do the interpretation. Patients can get the results right away.

Q: I've read that EBT has a potential for detecting early signs of cardiovascular disease, lung cancer, tumors and disorders of the liver and kidney. What does Tulane use it for?

A: It can be used for other purposes, but we've limited it here to coronary issues.

Q: What can it tell you?

A: Whether or not there are calcium deposits in the artery. These are not normally seen in normal vessels but are in arteriosclerotic vessels. A negative scan on EBT makes arteriosclerosis very unlikely, and that would indicate a low risk of coronary artery disease for the next five years.

Q: So the scan helps to detect risk?

A: There are separate risk factors for coronary artery disease. This ... gives us another modality to detect. It has a promising role, but (just how useful it can be long term) has not been firmly established. There is now a multi-ethnic study of arteriosclerosis, which is set up to evaluate the EBT as an indicator of coronary artery disease by detecting calcium. There's a lot of promising data, but standards are formed after major trials. We need to have some time to follow up on these people. We're expecting the major trial results to show it as a major way of screening for coronary artery disease.

Q: What about now?

A: It's being used currently to screen asymptomatic individuals to assess whether they are at risk for developing coronary artery disease and prone to coronary events in the future. A target population would be elderly individuals who are asymptomatic, however who have traditional cardiovascular risk factors. Using the EBT calcium score might have an incremental value for risk stratification for these patients. Also (EBT) might ... show the progression or regression in response to treatment. It has value as to how aggressively a patient should be treated.

Q: Statistically, when it comes to health conditions, heart disease is the No. 1 killer in the United States. What kind of impact could EBT have?

A: Pending the multi-center study that I mentioned, the current utility of the calcium score in predicting who is at risk for coronary artery disease has a major impact on how these people should be treated before coronary artery disease has developed. It has a preventative value.

Q: Is it the hope of the medical profession that EBT will become as common a preventative screening as a mammogram or prostate cancer test?

A: Exactly. That's being evaluated right now. Until the study is completed, the data is insufficient to recommend EBT for general population screening or general clinical use. In a few years, there probably will be a recommendation that the EBT be used for certain populations to screen for coronary artery disease.

Q: What is the cost and does insurance cover it?

A: It's officially not reimbursed right now. Nonetheless, patients can come by independently and get the test done and take it to their physician. It costs around $500.

Q: What makes EBT better than other scanning procedures?

A: The radiation exposure is about a tenth of the regular CT scan. Compared to traditional methods of stress testing, stress electrocardiogram, etc., it's the most sensitive method for detecting angiographic coronary disease. It's very sensitive. There may be some false-positive results. On the other hand, there are almost no false negatives. So if the screen is clean, (patients) can rest assured they will not be at risk for cardiovascular events.


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