After over a decade of development, the world's first full-body medical scanner has produced its first images. The groundbreaking imaging device is almost 40 times faster than current PET scans and can capture a 3D picture of the entire human body in one instant scan.
Called EXPLORER, the full-body scanner combines positron emission tomography (PET) and X-ray computed tomography (CT). Following years of research, a prototype, primate-sized scanner was revealed in 2016. After expansive testing, the first human-sized device was fabricated in early 2018.
Developed in a collaboration between scientists from UC Davis and engineers from Shanghai-based United Imaging Healthcare, the very first human images from the scanner have finally been revealed. The results are being described as nothing short of incredible and the research team suggests EXPLORER could revolutionize both clinical research and patient care.
"The level of detail was astonishing, especially once we got the reconstruction method a bit more optimized," says Ramsey Badawi, chief of Nuclear Medicine at UC Davis Health. "We could see features that you just don't see on regular PET scans. And the dynamic sequence showing the radiotracer 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 new EXPLORER scanner offers remarkable improvements over current imaging systems. As well as offering faster scans, producing a whole-body image in as little as 20 to 30 seconds, the device is effectively up to 40 times more sensitive than current commercial scanning systems.
This means the scanner can produce detailed images using significantly lower doses of radiation tracers than are currently needed. The higher sensitivity also allows clinicians to image certain molecular targets that are beyond the limits of current scanning systems.
"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," says Simon Cherry, from the UC Davis Department of Biomedical Engineering.
Perhaps the most exciting and novel application of this new scanning system is its ability to capture entire body images in single momentary scans. Current PET systems are fundamentally slow and inefficient due to the necessity of having to scan single slivers of the body at one time. Over a long stretch of 30 or 40 minutes all these smaller images are aggregated into a larger 3D image, however this significantly limits the ability of clinicians to measure the effects of something moving across the entire body in real time.
The EXPLORER promises an entirely new kind of diagnostic imaging that could, for example, measure blood flow or the way a person takes up glucose, in real time across the entirety of the body. The new imaging system still has some testing and verification ahead before it moves into commercial production but Cherry is optimistic it shouldn't be too long before it is available to hospitals and research bodies worldwide.
"I don't think it will be long before we see at a number of EXPLORER systems around the world," says Cherry. "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."