Chief of CT Lincoln Berland, M.D., has been actively involved with CT scanning for more than 30 of the 40 years it has been in existence.

Chief of CT Lincoln Berland stands with the new GE Healthcare CT 750 HD computed tomography scanner recently installed in The Kirklin Clinic.

“This really is one of the most exciting breakthroughs in CT technology in the past 20 years,” Berland says. “This is a scanner that can do what’s known as iterative reconstruction and dual-energy scanning, and it can do those while reducing radiation exposure to patients and still delivering high-definition images. This technology puts us on the cutting edge of this breakthrough.”

The high-definition, low-dose CT scanner was installed in The Kirklin Clinic in October and is the first of its type in the Southeast. It offers considerable benefits to patients concerned about radiation exposure, particularly those with conditions requiring multiple scans.

The scanner uses a conventional computer reconstruction method to create an image before repeating the reconstruction process — a process known as iterative reconstruction. This enables the scanner to produce a higher-quality image from a much lower radiation dose.

“What this does is create an image that has very similar characteristics in diagnostic quality to the conventional image, but it can be done with 50 to 60 percent of the radiation exposure you would ordinarily use,” Berland says. “We’re not really improving the quality of image, but we’re markedly reducing the dose, which is a big advantage to the patient.”

Dual-energy scanning
The CT scanner also contains a dual-energy scanning component, which makes UAB one of only a few sites in the country with the production version of this technology. The difference between dual-energy scanning and conventional CT is significant.

A conventional CT scan has an X-ray tube that generates a beam that goes through the patient as the tube rotates around the patient. The amount of the X-rays that are not absorbed in the patient is recorded when it hits the detector on the opposite side. With dual-energy scanning, an X-ray tube rapidly moves back and forth between two energies in milliseconds. The result is information with two different energies at almost the exact same time.

“That enables you to calculate the composition of tissues in the body based on the type of material in the body,” Berland says. “In other words, you can create images that highlight the iodine in the image, because all of the dye agents are iodine based for CT.”

Physicians have used the scanner to discover the differing composition of kidney stones, which can affect how they are managed. Berland says physicians also are looking at the extent to which the technology can improve the ability to identify subtle tumors in the liver and pancreas that may not always have been visible before.

“Now that we can focus on the iodine, we can create an image that’s weighted for iodine, so we can see tumors that pick up small amounts of iodine that we could not see with the older technique,” Berland says. “A physician might be able to catch something sooner and be able to affect management that way.”

Physicians also may be able to diagnose special conditions — like a deposition of iron or excessive scar tissue within organs — that they normally wouldn’t be able to identify. The dual-energy scan also can subtract metal when scanning patients with prosthetics or other metal in their body from an orthopedic surgical procedure. Previous scanners could not do that, leaving many images with star-like streaks that obscured the tissue and complicated diagnoses.

“That’s very important in patients who have had prior surgery,” Berland says. “They might have had orthopedic surgery and they’re trying to figure out if the prosthesis has loosened. Or they might have large surgical clips, and the place that a tumor is most likely to recur is where you operated on it. You can’t see it with a conventional test, and now potentially you can see that area.”

The scanner has been used on patients with pancreatic cancer and those who are at a higher risk for developing cancer, including patients with cirrhosis of the liver. Other patients who have a metastatic disease also are scanned on the machine, as are those with uncommon tumor types.

The scanner also can accommodate cardiac patients.

Lower dose aids patients
There is a disagreement among many experts on the level of radiation to be considered harmful.

Advanced technology enabling faster, easier CT exams, improved health care facilitated by data from CT exams, self-referrals and repeated examinations are some of the reasons Americans’ radiation exposure has risen six-fold in the past 29 years, according to a recent National Council on Radiation Protection and Measurement report.

Radiology endorses the “As Low As Reasonably Achievable” concept and an “Image Gently” campaign has been organized for pediatric imaging to help apply this concept. It encourages providers to use only the amount of radiation necessary to obtain optimal images.

“Two or three CT scans probably do not increase your risk of cancer, but we have lots of patients with certain kinds of conditions who get numerous CT scans,” Berland says. “Patients with cancer, those who have experienced trauma, or patients who have certain inflammatory conditions like Crohn’s disease or kidney stones may receive numerous scans. For patients who get many scans it’s going to be an advantage to use a scanner that gives a lower dose.”

Contact Berland for more information at lberland@uabmc.edu or 934-7978.