In a remarkable feat of scientific innovation, a British company called Kromek has developed a game-changing material that is transforming the world of medical imaging. Cadmium zinc telluride (CZT), a highly specialised semiconductor, is enabling hospitals to produce stunningly detailed, three-dimensional scans of patients’ lungs in a fraction of the time compared to traditional methods.
At the Royal Brompton Hospital in London, the installation of a CZT-powered scanner has cut lung examination times from 45 minutes down to just 15 minutes. “You get beautiful pictures from this scanner,” says Dr Kshama Wechalekar, head of nuclear medicine and PET at the hospital. “It’s an amazing feat of engineering and physics.”
Kromek is one of only a few firms globally capable of manufacturing CZT, a material that is in high demand across a range of industries. Its unique properties allow for precise detection of X-rays and gamma rays, making it invaluable for medical imaging, airport security scanners, and even space telescopes.
The production process for CZT is notoriously complex, involving special furnaces that heat the material to a molten state before slowly solidifying it into a single-crystal structure. “Atom by atom, the crystals are rearranged […] so they become all aligned,” explains Arnab Basu, founding chief executive of Kromek.
This precision is what gives CZT its remarkable capabilities. Unlike previous scanner technologies that relied on a two-step process, CZT-based systems can convert high-energy photons directly into electrical signals, retaining critical information about the timing and energy of the X-rays. This allows for the creation of highly detailed, colour-coded, and spectroscopic images.
The demand for CZT is growing rapidly, with the material being used not only in medical imaging but also in X-ray telescopes, radiation detectors, and airport security scanners. However, Kromek’s Basu acknowledges that the company faces challenges in meeting the diverse needs of its many research partners and customers.
“We support many, many research organisations,” he says. “It’s very difficult for us to do a hundred different things. Each research [project] needs a very particular type of detector structure.”
This scarcity of supply is being felt by scientists like Professor Henric Krawczynski at Washington University in St Louis, who requires thin, 0.8mm pieces of CZT for his X-ray telescope experiments. “It’s really difficult to get these thin ones,” he laments.
Despite these challenges, the impact of CZT technology is undeniable. The upcoming half-billion-pound upgrade of the Diamond Light Source research facility in Oxfordshire will rely on CZT-based detectors to capture the significantly brighter X-rays produced by the upgraded synchrotron.
As the world continues to push the boundaries of scientific discovery, the remarkable capabilities of Kromek’s CZT material are poised to play a pivotal role in revolutionising medical imaging, security, and a wide range of cutting-edge research applications.
