Video Shows How First "Total Body Scanner" Tracks Movement of Drugs in Body
On Monday, scientists revealed the first images of a human inside the world’s newest total body scanner, called EXPLORER. The name is fitting because this scanner really leaves absolutely nothing to the imagination, tracking the way drugs and disease progress through every nook and cranny in the body.
Designed by biomedical engineering professor Simon Cherry, Ph.D., and biophysicist Ramsey Badawi, Ph.D. at University of California, Davis, this scanner produces images that look like a hybrid between a PET scan (which is often used to find tumors) and an X-ray, all in ghostly black and white. But what’s interesting about EXPLORER, which will be officially unveiled at the Radiological Society of North America meeting on November 24th, isn’t that it produces detailed images of tissues or bones. Cherry tells Inverse that it can also create 3D movies showing where certain drugs may end up in the body.
We see this in the video at the top of this article, showing the scanner’s first images, taken at Zhongshan Hospital in Shanghai. In the video, which Cherry calls “a dynamic movie,” the subject receives an leg injection of F-18 fluorodeoxyglucose. It’s just sugar tagged with a fluorescent marker, which allows EXPLORER to trace it as it’s transported from the leg veins to the heart and far beyond.
“You can see the [glucose] entering through a vein in the leg, traveling to the heart where it is then pumped to the lungs which show up after a few seconds,” Cherry says. “It then goes back to the heart and is distributed through the arteries reaching all the tissues in the body.”
Around five seconds into the video, you can see the fluorodeoxyglucose’s tiny white light enter the heart and then explode outwards — powered by the heart’s pumping action — into the brain, lungs and variety of tissues. Over time, Cherry adds, the glucose accumulates in tissues like the brain, liver and kidneys. The scanner let us see what those tissues do with the substance once it’s there — that’s the process we know as metabolism. It also reveals more intimate details of human existence, like kidneys emptying into the bladder, around 16 seconds in.
At the end, Cherry adds, the scanner can produce a 3D map of the whole body in 20 to 30 seconds.
“Thus at the end of the video you are seeing a distribution which shows glucose metabolism in the body, and you can see high metabolism in the brain, heart and some in the liver,” he adds.
This scanner can help surmount one of the major challenges of drug delivery. When you put a substance into the human body, it ends up in a variety of places, some of which are unintended. This scanner can help drug delivery researchers make more targeted drugs that take fewer detours en route to their final destination.
The team is planning to bring one of these scanners to Sacramento, where they hope it will be operational by 2019. Since it’s very expensive to operate, says Cherry, the cost will have to come way down before its use becomes widespread. But being an unprecedented tool giving us never-before-seen glimpses into the human body, it could have numerous uses we haven’t even thought of yet.
“This is the first in the world,” Cherry says. “It may also well be the case that new research on this scanner that becomes possible because it can view the whole body at once, will eventually lead to new clinical applications,” he says.