Multimodality OEMs eye digital x-ray as Philips and Picker gain FDA nods

Siemens is on deck for its table and chest systems

As expected, the market for flat-panel digital x-ray systems is getting crowded, with multimodality OEMs jostling to claim their share of the pie. The two most recent OEMs to join the fray are Picker International of Cleveland and Philips Medical Systems of Shelton, CT, both of which received 510(k) clearances for x-ray systems based on amorphous silicon flat-panel technology. One other major vendor that is reportedly also close to market is Siemens Medical Systems of Iselin, NJ.

Philips and Picker were the recipients of fortuitous timing in getting their clearances: The Food and Drug Administration passed judgment on the digital systems in November, just prior to last year’s RSNA meeting in Chicago. Although the units from both companies are based on amorphous silicon flat panels, each has a different application and technological lineage.

Picker’s Live-X digital detector is part of the company’s Venue FACTS (fluoro-assisted CT) interventional CT suite, in which a digital C-arm is attached to the side of a CT gantry. The use of a flat-panel detector is crucial in this application. A standard image intensifier tube is too bulky and would require the interventional radiologist to stand farther away from the patient than is practical. Live-X enables the interventionalist to stand just behind the detector and within easy reach of the patient.

FACTS uses an 8 x 10-inch detector that operates at a fluoro rate of 15 frames per second and can store up to 100 seconds of fluoro loops. The detectors have image-quality advantages over image intensifier tubes in that they have edge-to-edge uniform resolution, according to Richard Silver, sales and marketing manager for Picker’s x-ray division.

As Picker pointed out at the RSNA meeting, Live-X’s clearance is the first for a flat-panel digital fluoroscopy application. Live-X is based on the VIP-9 detector developed by Varian Associates of Palo Alto, CA. Varian early on targeted fluoro applications for its technology, even though digitizing dynamic studies is a greater engineering challenge than static x-ray.

In addition to its use with Venue FACTS, Picker plans to use the Live-X detectors in conventional x-ray systems in its product line. The company unveiled a new radiography table, called RadView, that will be upgradable to the digital detectors, according to Silver. It also showed a workstation displaying static x-ray images.

But fluoroscopy remains the company’s primary focus. That’s because the use of flat-panel detectors in fluoroscopy systems will enable vendors to radically redesign R/F units by eliminating bulky and heavy image intensifier tubes. Flat-panel radiographic detectors, on the other hand, do not differ much in size and weight from screen-film cassettes.

“We see tremendous benefit to flat-panel fluoro,” Silver said. “Efficiency is going to improve with radiographic flat panels. There is no question about it. But in fluoro, flat panels are going to change the whole look and feel of interventional, R/F, and surgical systems, with lighter weight imaging chains.”

Philips, on the other hand, highlighted radiography applications possible with Digital Diagnost, a new bucky-style x-ray system that uses an amorphous silicon flat-panel detector. Like Live-X, Digital Diagnost received 510(k) clearance in the weeks prior to the RSNA meeting.

Digital Diagnost is based on the company’s conventional Bucky TH x-ray system, but employs a Pixium 4600 detector manufactured by Trixell, the French digital x-ray joint venture between Siemens, Philips, and Thomson Tubes. The 43 x 43-cm detector has a pixel size of 143 microns. The first Digital Diagnost unit has been installed at the University of Bremen in Germany. Philips is using it to demonstrate the system’s image quality and impact on radiology department work flow, according to Hans Kleine Schaars, international marketing manager. Philips estimates that commercial shipments will begin this summer.

Unlike most companies that have concentrated their digital development efforts on chest imaging, Philips targeted a bucky-style unit as its first application for digital. This is because the company already has a digital chest system in its arsenal, the selenium-based ThoraVision. That product has advantages over many of the digital units coming to market due to its 19-inch field-of-view, which is several inches larger than existing digital systems and is a major advantage for chest imaging, Schaars said.

Like Picker, Philips is examining fluoroscopy applications for the detectors but is on a slower development timeline. A Philips flat-panel fluoroscopy system has been installed at Leeds Infirmary in London for over a year, but Philips executives estimate that it will be up to three years before the company is in full production on a commercial unit.

In the Siemens booth at the RSNA meeting, the vendor displayed the Trixell detectors integrated with a table system, called Multix FD, and a chest unit, named Thorax FD. Although the company did not have FDA clearance for the units, it has filed 510(k) applications and expects to receive them shortly. Commercial shipments should begin in the second half of the year, according to Kurt Reiff, product manager for radiographic tables.