What Is Photon-Counting CT — and How It Could Change the Way You’re Diagnosed

The next wave of diagnostic technology has come to Westchester County, with a new computed tomography (CT) scanner at NewYork-Presbyterian The One, a multispecialty care facility in White Plains, NY. The photon-counting CT scanner—the first in the county—produces significantly more detailed images at a fraction of the radiation required for traditional CT scans.

“There’s a lot of interest in this new technology, both from patients and their referring physicians,” said Stuart Bentley-Hibbert, MD, PhD, associate professor of radiology and vice chair of imaging regional network for the Department of Radiology at Columbia. “It’s a game-changer for our ability to provide fast and accurate diagnoses without exposing patients to high doses of radiation.”

Often the first step in determining the course of a patient’s treatment, a traditional CT scan converts X-rays into images through a two-step process, first converting them into light and then to an electrical signal. This process affects the image resolution. With photon-counting CT, X-ray photons are converted directly into digital electrical signals and then counted without information loss—adding a wealth of new, clinically relevant information to the images.

Shorter Scan Times, Less Radiation

Patients who are undergoing diagnostic exams with photon-counting CT may notice shorter scan times. They will also be exposed to a lower dose of radiation than a traditional CT. “Patients who receive multiple scans are reasonably concerned about their radiation dose,” says Bentley-Hibbert. “This new technology uses significantly less radiation to capture incredible detail in the images.”

Detecting Disease Without Invasive Tests

For Columbia’s cardiac patients, the new technology may lead to fewer invasive tests. Patients with significant coronary artery disease can be challenging to evaluate with traditional CT, says Jay Leb, MD, director of cardiac imaging for the Department of Radiology. Contrast dye is used during a scan to highlight the blood vessels; however, the presence of calcified plaque can interfere with the accurate assessment of the arteries. “Both the contrast dye and the plaque are bright on a CT scan,” says Leb, explaining that patients with calcified plaque may have to undergo more invasive diagnostic procedures, such as cardiac catheterization, for a conclusive diagnosis.

Patients with stents also present challenges due to the stent's density, Leb says, making it hard to see if plaque has built up inside them. “This new technology opens up our ability to image complex patients with coronary artery disease,” says Leb. “We can now offer these patients CT with confidence and evaluate the images accurately.”

A Wealth of New Information About Small Structures

Radiologists who specialize in imaging of the head and neck use CT to evaluate the many tiny bones and vessels around the ear, inner ear, and neck. The large number and small size of these structures present a unique set of diagnostic challenges. “We could use a very high dose of radiation with standard scanners and see these structures clearly,” says neuroradiologist William Gomes, MD, PhD, associate professor of radiology at Columbia University Irving Medical Center, “but we want to limit the radiation dose.” This sometimes leaves uncertainty around structures which may be involved in the diagnosis of hearing loss, vertigo, infections, congenital malformations, and tumors in the head and neck.

“There’s a huge improvement with the photon counting CT technique,” he says. “We are excited to provide more accurate diagnoses to our partners in otolaryngology.”

Photon-counting CT will improve everything from annual lung cancer screenings to the monitoring of cancer treatment, says Bentley-Hibbert, adding that the technology is still not widely available in the New York City area. “We’re excited to be the first to offer this cutting-edge imaging technology to our Westchester patients,” he says.