The scanner, known as the Explorer, is a combination of a positron emission tomography (PET) and X-ray computed tomography (CT). It is able to image the entire body using both scanning methods and can produce the image in as little as one second. Over time, Explorer can make videos that can track specially tagged drugs as they move through the body.
UC Davis scientists Simon Cherry and Ramsey Badawi developed the scanner and suggest that the technology could be used in a number of applications that include improving diagnostics, tracking disease progression and researching new drug therapies. Explorer was developed in a partnership with Shanghai-based United Imaging Healthcare and will manufacture the devices for a broader healthcare market.
“While I had imagined what the images would look like for years, nothing prepared me for the incredible detail we could see on that first scan,” Cherry, a professor in the UC Device Department of Biomedical Engineering, said in a press release. “While there is still a lot of careful analysis to do, I think we already know that Explorer is delivering roughly what we had promised.”
Images from the Explorer scanner were collected in a collaboration with United Imaging Healthcare and the Department of Nuclear Medicine at Zhongshan Hospital in Shanghai, China.
“The level of detail was astonishing, especially once we got the reconstruction method a bit more optimized,” Badawi said. “We could see features that you just don’t see on regular PET scans. And the dynamic sequence showing the radio tracer moving around the body in three dimensions over time was, frankly mind-blowing. There is no other device that can obtain data like this in humans, so this is truly novel.”
The UC Davis scientists thought of the total-body scanner 13 years ago. They kickstarted the idea in 2011 with a $1.5 million grant from the National Cancer Institute that allowed them to gather a consortium of researchers and other collaborators. The team received a $15.5 million grant from the National Institutes of Health in 2015 that allowed the team to team up with a commercial partner and to build the first Explorer scanner.
Cherry and the other researchers suggest that the Explorer scanner will have an impact on clinical research and patient care because of its higher-quality diagnostic PET scans. Explorer is able to scan up to 40 times faster than current PET scans and can produce a diagnostic scan of the whole body in 20 to 30 seconds.
With all of the imaging capabilities, Explorer is still able to scan with a radiation dose up to 40 times less than a current PET scan.
“The tradeoff between image quality, acquisition time and injected radiation dose will vary for different applications, but in all cases, we can scan better, faster or with less radiation dose, or some combination of these,” Cherry said.
The Explorer scanner would be able to evaluate what is going on in all the organs and tissues in the body at the same time, according to the researchers. Blood flow could be quantitatively measured and the scans could show how the body takes up glucose. The researchers suggest that the scanner could be used to study cancer that has spread beyond a single tumor site, inflammation, infection, immunological or metabolic disorders and many other diseases.
“I don’t think it will be long before we see at a number of Explorer systems around the world,” Cherry said. “But that depends on demonstrating the benefits of the system, both clinically and for research. Now, our focus turns to planning the studies that will demonstrate how Explorer will benefit our patients and contribute to our knowledge of the whole human body in health and disease.”
The researchers are currently working with UIH to get the first system delivered and installed in a leased space in Sacramento. The researchers hope to begin a research project and image patients using the Explorer scanner as early as June 2019.