Siemens and GE buy into CZT producer Imarad

Israeli company developing large-field gamma ray detectors

Imarad Imaging Systems came up a winner June 5 with the simultaneous announcement that Siemens and GE had each bought minority shares in the privately held Israeli CZT detector company.

Siemens’ action furthers a relationship it started with Imarad in 1996 in a joint project to develop a large-field, solid-state CZT-based gamma camera for nuclear medicine imaging. That project officially ended in 1999, but the technical relationship continued, according to Shimon Klier, chairman and CEO of Imarad.

GE acquired early CZT technology when it formed a joint venture called ELGEMS with Israel-based Elscint two years ago. Elscint eventually sold its nuclear medicine interests to GE.

CZT detectors are based on cadmium zinc telluride crystals, which, when combined with semiconductor electronics, convert photons into digital signals without the use of photomultipliers or analog-to-digital converters. Digirad of San Diego received a 510(k) clearance for its 2020 TC Imager using CZT in 1997, but its relatively small detector head limits its ability to do whole-body scans (SCAN 6/11/97). Although brain and cardiac applications in nuclear medicine can use small detectors, a research goal has been to develop a plate that allows coverage of much larger areas.

Both GE and Siemens have had their own R&D projects to develop CZT plates, a technology that could replace sodium iodide plates with their array of photomultiplier tubes.

Imarad has developed a process for growing the CZT crystals and producing modules, while GE and Siemens will bring their knowledge of how to incorporate those modules into nuclear medicine devices.

Siemens estimates the time to bring a CZT detector to market could be as short as one year or as long as five to 10 years, depending on cost and how quickly they can make the product work, according to Barbara Franciose, Siemens group vice president for worldwide nuclear medicine.

“We will provide our knowledge of the product base and the improvements we need and they (Imarad) will provide the process,” she said.

The advent of CZT-based detectors will move nuclear medicine past crystal scintillators and photomultiplier tubes and into a fully digital arena, Franciose said.

Although Beth Klein, global general manager of the nuclear and PET business at GE Medical Systems, denied that her company had been talking with Siemens before the simultaneous announcements, Franciose said there had been some discussions. Siemens was working in Israel with Imarad while GE was collaborating with Elscint.

“We were just trying to put our heads together in terms of the technology,” Franciose said. “Three heads are better than one. We feel we have to get out of old-fashioned boundaries where we thought we had to do it ourselves and kill the competition. We feel this is going to help our customer base, to have an investment in technology from two competitors to perfect something that will help all nuclear medicine imaging.”

Space-based astronomy led NASA engineers to develop the CZT gamma ray detector (SCAN 9/3/97), and the U.S. military has had a long-time interest in CZT as a radiation detector. The federal government reportedly subsidized its development for military applications.

According to Imarad’s Klier, the CZT technology developed and used by his company was started in 1990 at Urigal Technologies, headed by Dr. Uri El-Hanany. Imarad purchased the rights to the technology in 1995, and later acquired all Urigal Technologies’ shares. El-Hanany is the largest Imarad shareholder, Klier said.

“We kept it very, very secret and only announced we were working on detectors a year and a half ago,” Klier said.

While Imarad was working with Siemens on the large-field CZT-based gamma camera, the company developed a working relationship with GE when GE was in Israel for the joint venture with Elscint, Klier said.

“These two projects were totally separate and there was no Siemens-GE-Imarad cooperation at any stage,” he said.

“We, too, have been working with Imarad in developing CZT,” GE’s Klein said. “Imarad approached both companies and asked them to take equity stakes.”

Klier said he was a little surprised that GE and Siemens issued separate press releases rather than a joint one about their Imarad stock purchases.

“It must have been the lawyers’ decision,” he said.

Although Imarad is privately held, Klier said his company is looking at the possibility of going public on the Israeli stock exchange.