Surgeons view digital holograms using PACS data

PACS data from MR and CT scans are being used to feed a digital holographic system for the benefit of neuro and orthopedic surgeons. The views created by the Voxel's Digital Holography system recreate anatomy unlike any existing pseudo-three-dimensional techniques, according to the manufacturer.

Digital holography has been used for nearly a year in the surgical suites of Primary Children's Medical Center (PCMC) in Salt Lake City, a regional pediatric referral center for the Intermountain West.

"Our neurosurgeons operate in a filmless environment now," said Darin Day, medical imaging informatics administrator at PCMC. "With our PACS, we're building holograms for neuro and orthopedic surgeons."

Because all of the information coming from the PACS is digital, it can be sent directly into the Voxel system, which consists of a digital interface, laser camera, and holographic light box. Together these components produce a "Voxgram" - which Voxel calls the world's first true 3-D image.

"We make real holograms," said Stephen Hart, Voxel's chief technical officer. "We take the slices from a CT or MR scan and print them one behind another in their relative positions, literally projecting in space."

Users can then navigate 45° left or right, up or down.

"As you move in and out, everything changes correctly," he said. "We're not limiting it to something on the surface. It's transparent so you can see what's on the inside as well. You see the whole volume."

With digital holography, neurosurgeons are able to plot their way to a tumor preoperatively, just as orthopedic surgeons can simulate placement of pedicle screws prior to performing surgeries, saving surgical time and expense.

"Digital holography enables us to plan trajectories, operate on the patient with more confidence and safety, assess complex anatomical relationships, and use the hologram in the OR as a neuronavigational device," said Dr. Patrick J. Kelly, chair of neurosurgery at New York University Medical Center.

The problem with traditional x-rays is that they represent 2-D images of 3-D objects. While MR and CT address this problem by providing cross-sectional slices, each of these is still a 2-D picture of a single body plane, and the physician is left to imagine the integration of the slices into a meaningful 3-D whole.

Navigating these cross-sectional images has become more and more difficult as the quantity of data has increased to hundreds of submillimeter sections. Surgery is performed on 3-D patients, however, not on their 2-D sections. In order to fully visualize 3-D anatomical relationships within the patient, surgeons require a "3-D x-ray view" of the patient. Voxel's proprietary technology provides this.

Voxel will determine in the future whether to market the technology to the general radiology community.