Small crystals - big impact

The small things that contributed to changing the world of diagnostic imaging measure 3.2 by 3.2 by 20 millimeters. They reflect the light, and as you turn them around, they sparkle like diamonds. Mark Andreaco is holding one of these little wonders between the thumb and forefinger of his right hand. They are called scintillator crystal pixels. 

"At Rockford we have three facilities where we perform detector R&D, detector operations, and the growth of crystal material," Mark explains as he guides guests through those plants. As vice president of the Siemens Healthineers Molecular Imaging Detector Center he is responsible for the plants. In addition, he is a member of the Siemens Molecular Imaging Executive Team. The patents that he holds and the innovations that he launched together with his teams over two decades were considerations for his being awarded Siemens "Inventor of the Year 2021" in the category Lifetime Achievement.

"The detectors manufactured from the Rockford plants are significant components that contribute to the technology offered by the Siemens Healthineers Biograph Vision systems. The Biograph Vision systems opened up whole new worlds of precision in diagnostic imaging: Whole-body scans can be conducted with a stunning level of sensitivity. "The detail that one can see, the sensitivity and the size of the tumors – it's just a greatly enhanced device, which provides Siemens an advantage in the market," Mark says. 

The story of Mark's professional life is one of overcoming obstacles, dealing with disruptive increases in the world market price for raw materials and inventing technologies because there were no commercial solutions in the market. "When you are developing technology, you run into problems that you have no experience with," Mark answers when asked about the main drivers in his professional life. For him, innovation happens between like-minded people and – in his case – with a strong company that believes in their ideas. "We have always had very creative and diverse teams, and we were enabled by corporate will. So, we solved such problems. We were driven by a sense of ownership and the challenge of overcoming obstacles outside our experience realm." 

Problem-solving was needed when the world market price for the lutetium oxide raw material was so high that it was not commercially viable. "The problem lay with the availability of the raw material," Mark explains. "Lutetium Oxide is one of 15 lanthanides rare earth elements. It's the last and rarest of the rare earths. At the time of the discovery of LSO:Ce by Charles Melcher there was only 100 kilograms of Lutetium Oxide commercially available worldwide. For perspective, BGO scanners at that time used 75 kilograms of scintillator. So, under the best of circumstances, considering yield losses, we could not have constructed a single machine from the world's supply of lutetium. The reason was: There was no demand in any of the industries worldwide.”

But at Rockford, there was a demand. Because the LSO:Ce scintillator crystal pixels are at the core of the power of the Biograph Vision systems. “The scintillator crystals convert the radiation from the injected PET tracer emanating from the body of a patient into light of a certain wavelength. That light is detected by an optical sensor and converted to an electrical signal that is subsequently processed into a reconstructed image”, Mark explains. The Cerium doped Lutetium Oxyorthosilicate scintillation crystals are grown in high temperature furnaces at a temperature around 2150 degrees Celsius . 

To enhance the supply of lutetium oxide, Mark continues to explain, “one would have to increase the quantity of the preceding 14 rare earths elements through enrichment as a byproduct of the enrichment process of lutetium oxide.  In doing so, you increase the inventory of those 14 rare earths. And someone has to pay for that increased inventory." At the time, the price ranged between$4,000 and $15,000 per kilogram. At those prices, it was not commercially viable. One of the founders of CTI – the company that Mark worked for at the time and that has been acquired by Siemens Healthineers – made a trip to China. He brought back 10 tons of two percent enriched rare earth oxides and said to Mark, "Refine this, find out how to enrich this." Mark was given the task of learning how to enrich the purity of lutetium oxide and make it available for use. “We learned the technology through the development of a lab scale pilot plant. We leveraged that knowledge to enter into a long-term supply agreement with a commercial refinery that met our price and quantity requirements.” 

Problem-solving is also what happened when Mark initiated a business plan to grow scintillator crystals in-house in Rockford. According to Mark, lutetium-based scintillators were not available in the medical marketplace before establishing the Rockford plant. "What distinguishes Siemens in my view," Mark says, "is its corporate will: To do what is necessary to understand disruptive technologies and the market potential. The corporate will was to develop a business plan, acquire the patent rights, provide financing, engineering and equipment resources to build the plants, and staff with diverse, talented teams empowered by a sense of creative ownership.”

None of them had any experience building a high-temperature crystal growth plant or creating an assembly operation for building massive numbers of scintillators and detectors. Significant increases in the volume of the scintillators were made without additional capital expense, and they were based on just innovative ideas. "As I reflect upon my career, there isn't a single innovation that I have had that was not the result of trying to solve a problem that had no commercial solution," Mark reflects on his lifetime achievement. " Many times, problem-solving turned out as a new business opportunity."