Viewing organs in a heartbeat

New scanner offers better imaging, less exposure

By Russell Rian 

May 2010

UT Southwestern is the first site in North Texas to launch the next generation in CT scanners, which allow doctors to image an entire organ in less than a second or track blood flow through the brain or to a tumor — all with less radiation exposure to patients.

Aquilion One dynamic volume computed tomography (CT) can create a detailed 3-D movie of an organ in real time. That makes it particularly useful for quickly diagnosing strokes and heart attacks, for example, where diagnostic speed can be a critical factor in survival and recovery.

Because the machine’s technology can take continuous or intermittent images,
UT Southwestern radiologists anticipate better visualization in neurology, trauma, whole body, lung, cardiac, vascular and pediatric studies. Other applications include providing distinctive capabilities in orthopaedic and joint studies, diagnosing renal function, and even vocal-cord analysis.

Drs. Phil Evans (left) and Michael Medina, assistant vice president for health system imaging services, are overseeing the installation of the Aquillon One CT scanner.

For patients, the new technology can mean less time in a scanner and less exposure to radiation, said Dr. Phil Evans, associate vice president for clinical imaging services and professor of radiology.

“Dose has been a concern in the medical literature for a long time, and people have been very concerned about it,” said Dr. Evans, who directs the UT Southwestern Center for Breast Care. “One of the great things about this is that you can do a scan with about half the radiation dose and half the contrast media, so the dose is less and the image is better.”

Other scanners piece together strips of images to compile a complete picture, using four-, 16-, 32- or 64-slice machines. Aquilion One, manufactured by Toshiba, exposes patients to less radiation because one strip covers a larger area, therefore requiring fewer swaths overall and less time. The result can be as much as 80 percent less radiation in some cases, according to published research.

Aquilion One uses 320 high-resolution X-ray detectors in each rotation. What takes 12 to 15 seconds for other scanners to complete takes only about one-third of a second for the 320-slice machine. Aquilion One can take images continuously or intermittently, allowing doctors to see the heart pumping or blood or medication working through the vascular system.

“One of the most exciting things about this technology is the real-time ability to image changing anatomy,” said Dr. Phillip Purdy, professor of radiology and neurological surgery. “We have been able to image physiology, such as blood flow in parts of the brain, but now we can image the entire brain faster and more safely.”

Using Aquilion One, UT Southwestern physicians said they will be able to accurately diagnose a stroke or heart attack in about 20 minutes, as well as be able to gauge tissue damage. Currently, doctors often perform a battery of tests to confirm a heart attack — an EKG, CT angiography, nuclear testing and catheterization – which can take hours or even days.

Clinically, the new technology enhances the medical center’s expertise, including:

  • For possible strokes, diagnosis and treatments need to occur within hours. Physicians will be able to clearly see areas of the brain that aren’t getting enough blood and oxygen.
  • In cancer cases, the ability to track blood flow to a tumor can help in determining whether a particular treatment protocol is working and will allow physicians to tailor medication adjustments for the best outcome.
  • For pediatrics, the larger swath and quicker scan can image an entire midsection or vascular system of an infant.
  • In orthopaedics, the faster, larger image can show blood movement or tissue damage as well as reduce the need for additional imaging tests.

Patients who can’t get an MRI due to the presence of a pacemaker may be candidates for the new machine, as well as patients needing vocal-cord analysis capturing a patient phonating. The device provides added flexibility in properly positioning patients with trauma or disabilities and is sturdy enough to accommodate obese patients.

UT Southwestern physicians also anticipate that the Aquilion One device will be valuable in many of the medical center’s unique research projects. For example, the ability to move backward and forward in time through the images may help researchers better visualize the effects of tissue damage or vascular flow.

“This has the potential to impact the daily medicine we currently practice and help us identify future clinical pathways,” Dr. Evans said. “UT Southwestern is fortunate to have clinical experts and forward-looking researchers who will really be the ones to determine its best uses. Technology, even the best technology, still depends on the expertise of those using it.”

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Dr. Evans holds the George and Carol Poston Professorship in Breast Cancer Research.

Dr. Purdy holds the Orien and Jack Woolf, M.D., Distinguished Chair in Neurosurgery and Neuroangiography.