CT scanner offers comfort, clearer images

For Martin "Marty" Bernstein, the latest computed tomography (CT) scanner at UT Southwestern - the only one of its kind in the region - means getting the best treatment for his vascular disease and with less discomfort.

"It's a lot easier and quicker than any other CT scan I've had before," said the 57-year-old Mr. Bernstein, a former wholesale business owner from Dallas who has undergone about a half-dozen such scans.

For doctors, the CT scanner provides images with resolution and definition so clear that it not only pictures coronary artery plaque buildup, but often allows them to identify the composition of the calcium in the plaque.

A CT scanner is a large donut-shaped machine that emits X-rays that go through the body and are recorded by electronic detectors. These detectors transmit the data to a computer for processing as cross-sectional views or "slices."

UT Southwestern's latest device is a 16-slice CT scanner with cardiac gating - timing that synchronizes the views as the heart contracts and relaxes - that aids doctors in assessing coronary artery disease, stroke and other disorders.

With the new General Electric Lightspeed CT scanner at the James W. Aston Ambulatory Care Center, 16 separate slices are produced in one revolution of the camera instead of one scan image at a time. The device performs most routine studies, such as cardiovascular scans and lung analysis, in 15 seconds or less. Traditional single-slice scanners do the same studies in 30 to 40 seconds.

About 30 scans per day are performed with the 16-slice scanner at the Aston radiology clinic.

"Our sensitivity for detection of internal disease processes has been greatly enhanced by our new CT scanner," said Dr. Cecelia Brewington, executive medical director of radiology.

A major use of the cutting-edge technology is as a screening test for determining whether patients are at high risk for coronary artery disease. The 16-slice CT scanner can conduct a computer-generated coronary angiogram that produces a 3-D image of the coronary arteries in 30 seconds as a brief outpatient procedure.

With cardiac gating, the scanner synchronizes the images of the heart with different parts of the cardiac cycle (contracting or relaxing) as an electrocardiogram records the electrical currents that activate the heart muscle and cause it to pump.

This less invasive procedure can screen the need for a standard angiogram that requires an invasive procedure of puncturing an artery and inserting a catheter, said Dr. Brewington. The resolution and definition are so fine that plaque buildup can be visualized similar to a coronary angiogram.

The new scanner also can conduct CT perfusion, a neuroimaging technique that enables the evaluation of blood flow in the organs. For example, stroke can be diagnosed at an early stage through this procedure, which is not possible by conventional CT scanning.

Further, the new technology performs calcium scoring to detect calcium buildup that indicates blockages of heart arteries. It can take full lung scans quickly without requiring patients to hold their breath or position themselves for long periods of time. And by performing a noninvasive continuous scan from the diaphragm to the rectum, doctors can detect polyps and other problems in the colon.

For Mr. Bernstein, the 16-slice CT scanner was a beneficial advance in his continued treatment.

"This new scanner puts less stress on the patient, and that's always important," said Mr. Bernstein. "If anyone needs a CT scan, this definitely is the way to go."