Back in 2017, HealthCare Business News spoke to Ramsey Badawi and Simon Cherry about the total body PET scanner they were developing at UC Davis. As we described it at the time, it was a “research project that could one day revolutionize molecular imaging.”

With the annual SNMMI meeting right around the corner, we decided to check back in with them to see what the last few years have been like, and what’s on the horizon.

HCB News: A lot has happened since we first spoke to both of you in 2017 about your total body PET scanning project. For one thing, the scanner is FDA cleared and is being manufactured by United Imaging. What has that journey been like on a personal level?
Ramsey Badawi and Simon Cherry: It’s been incredibly busy! 2018 and the first part of 2019 were spent designing and planning for the new EXPLORER Molecular Imaging Center (EMIC), which now houses the scanner. And since June 2019, when we started scanning, we have had a huge amount of work to do in setting up both the clinical and research services that EMIC provides. Some of the high points were when we saw the very first human subject scan from the first prototype, and then again when we saw the images from the first human subject acquired at UC Davis. These were career-defining moments.

HCB News: Can you tell us about some of the research being done with the scanner that you're most excited about?
RB & SC: There is some very exciting work being done on imaging CD8 positive T-cells in COVID-19 patients. We have also seen some game-changing results when using Zr89 immunoPET to image HIV distribution with our collaborators at UCSF. While it is still early days on this project, the images are so dramatically superior to what is possible on conventional PET that we can’t help but feel that the power of these kinds of studies will be significantly improved.

We also have a program using TB-PET to image systemic disease burden in arthritis. We can get fantastic high-resolution images of inflammatory activity in joints and tendons throughout the body, and with much lower doses to the subjects.

We also have a lot of methodological research underway using deep-learning method — for example, to detect and correct for motion during a scan and to improve image quality at low doses.

HCB News: Have any indications or diagnostic use cases emerged where the whole body scanner is particularly useful?
RB & SC:Pediatric imaging is an obvious area. If the patient can’t lie still for the time normally needed for a conventional PET scan, we can still get great images. For adults, our radiologists tell us that, particularly in the liver, the increased image quality gives them much more confidence in the findings, which can reduce the need for further imaging studies with MR. Due to the improved spatial resolution and signal collection efficiency, it is also much easier to assess small lung nodules.

HCB News: In the past we talked about peers questioning the clinical value of such a heavy duty scanner, has that changed?
RB & SC: There are, of course, legitimate concerns about cost for such a scanner, and these concerns are amplified for centers that don’t have a research portfolio. In parts of the world where there is significant unmet need, a high-throughput scanner like EXPLORER can justify itself quite easily. In places where clinical demand is lower, the argument revolves around the value that very high-quality imaging brings to patient care, and we are still collecting data to answer that question. But the groundbreaking value of this scanner is really in doing things that could not be done before, such as total-body systems imaging, total-body parametric imaging, and high-quality immunoPET.

HCB News: Has anything about the uExplorer surprised you? Does it have capabilities you hadn't foreseen in the development stages?
RB & SC: Perhaps the most remarkable capability is the ability to perform total-body dynamic imaging with 100 ms frame-rate. We have now seen radiotracer being mixed in the chambers of the heart with each individual heartbeat, and pumped around the vascular tree in three dimensions. We never imagined that we would be able to do this when we conceived of this scanner.

HCB News: As researchers pushing the boundaries of what's possible in medical imaging, what do you think might be possible in another 10 or 15 years?
RB & SC: Scientists in our lab and in other labs around the world are busy developing PET detectors that are 20 times faster than the ones used in the EXPLORER scanner. Once such technology can be scaled up, this is going to result in total-body PET that is at least an order of magnitude more powerful than the EXPLORER scanner. Given that we have yet to fully determine what the current scanner can do, the possibilities for the future are wildly exciting!

HCB News: What do you see as critical healthcare challenges (globally or within the U.S.) that require more urgent attention?
RB & SC: One could argue that key healthcare challenges of our time relate to obesity and its related metabolic, cardiac, vascular, musculoskeletal and oncogenic consequences. There is a critically important role for total-body PET in understanding the systemic interactions that underpin these consequences and in finding ways to improve the underlying health of the population. Both the low-dose capabilities and the total-body imaging capabilities of the technology are critically important in this effort.

HCB News: Do you have any new projects in the pipeline?
RB & SC: Many! In terms of scanner building, though, our key effort is another collaboration with United Imaging Healthcare, this time led by Yale University — we seek to build the next-generation, ultrahigh-performance brain PET scanner: the NX, or Neuro-eXplorer. This was recently funded by the NIH BRAIN initiative. We’re also bringing online new radiotracers, with one focus being the development of methods to quantify perfusion and blood volume throughout the entire body. We also have plans to expand into areas where PET has not been widely used, for example, in studies of nutrition and meditation.