Healthful Advice . Dr. Kenneth Adams
Having grown up in the "Star Trek" era, I remember the doctor on the Starship Enterprise making most of his diagnoses by moving a cursor over the patient's body. "Bones," as the doctor was affectionately called, would then turn to Captain James Kirk and give him a full report. This was the ultimate non-invasive test. Although we are many years from making diagnoses that way, we may have moved a few steps closer with the advent of cardiac CT scans.
For centuries, doctors have tried to assess internal organs by examining from the outside. In the case of the heart, one early method was to simply put your ear to the patient's chest and listen to the heart rhythm. This became more sophisticated with the use of a pipe and then a stethoscope.
Coronary artery disease, or blockages in the arteries feeding the heart muscle, is the leading cause of death in the United States. One of the challenges has been to obtain detailed and accurate information about the coronary arteries without doing an invasive procedure. Our "gold standard" for detailed and accurate information about coronary arteries has been cardiac catheterization. This is an invasive procedure that involves inserting a small tube or catheter into an artery at the top of the leg, threading this tube up to the heart, pointing the catheter into the coronary arteries, injecting contrast and taking an X -ray moving picture of the arteries.
Is there a way to obtain good pictures of the coronary arteries without doing an invasive procedure? The newer generation of CT scans offers a lot of promise, allowing us to perform angiograms using CT technology. CTA stands for computed tomographic angiography. CTA has been used for imaging many arteries including the aorta, kidney arteries and carotid arteries.
One of the difficulties in obtaining accurate Cardiac CTA relates to the heart being a structure with a lot of movement. In order to take accurate pictures of a moving object the pictures must be taken in a very short time frame. CT scans with a high number of detectors or "slices" can take pictures in a very short period of time. Right now, a 64-detector CT scan is being used for cardiac CTA. After timing measurements are made to determine when the contrast will reach the heart, contrast or dye is administered through an IV. The scanner is positioned over the heart. Pictures of the heart can be taken in five to ten seconds.
This is a very exciting technology, but it has its limitations and does not apply to every patient. Let me give you one example of a patient who would be a good candidate for cardiac CTA. I recently saw a 45 year-old patient in my office who was sent to me for evaluation of chest pain. The chest pain had some features that suggested the possibility of coronary artery disease, but I had my doubts. The patient did have some risk factors for heart disease, including high cholesterol and family members with coronary artery disease. This patient's stress test was inconclusive. I really wanted to know whether this patient had any blockages in her coronary arteries but I did not think an invasive procedure was warranted. I knew cardiac CTA might give me the information I was looking for.
Cardiac CTA has generated a lot of enthusiasm in the medical community. Articles about cardiac CTA have been in Newsweek and Time magazines, and there was even a segment on “Oprah.” Many cardiologists and radiologists have taken special training to learn how to read cardiac CT scans. Medical providers have to make sure they select the right type of patients for cardiac CTA.
Cardiac CTA is available in our community so that we may (to paraphrase from "Star Trek") boldly go forward, seeking new information for our patient.
Dr. Kenneth Adams is the senior Cardiologist at Pentucket Medical Associates and is certified in Cardiac CTA. Dr. Adams can be reached at 978-521-3288 for additional information about this procedure.