Advanced MRI Detection Technology for Screening Liquids at Airport Security
Los Alamos National Laboratory scientists have advanced a Magnetic Resonance Imaging (MRI) technology that may provide a breakthrough for screening liquids at airport security. They've added low-power X-ray data to the mix, and as a result have unlocked a new detection technology. The new system is called MagRay. "We've been able to look at a really broad class of explosives, we've been able to look through all kinds of packaging, and we've unlocked a new parameter – proton content – that's not available to either X-ray or MRI alone," says Michelle Espy, LANL physicist and MagRay Project Leader. "We're looking for where a liquid lies in a sort of three-dimensional space of MRI, proton content, and X-ray density," adds MagRay engineer Larry Schultz. "With those measures we find that benign liquids and threat liquids separate real nicely in this space, so we can detect them quickly with a very high level of confidence."
Transcript
00:00:01 Michelle Espy: Right now, because of a lack of any better methods, the public is constrained in how much liquid they can take on board an airplane ... One of the challenges for the screening of liquids in an airport is that the traditional methods that people have used for years to secure airports, X-ray, are not particularly well suited for liquids. A technique like magnetic resonance is very well suited for looking at liquids and gels, it's the premier technology, for example, for looking at soft tissue in a hospital or medical imaging setting. Larry Schultz: Just using the NMR signature, we can tell quite a few threats as distinct from our family of benigns, but there's a certain set of liquids ... home-made explosives, complex mixes, where the NMR signature is not quite enough to tell us, with high confidence,
00:01:03 that this material is a threat or benign. Espy: With the support of DHS we began to investigate bringing this magnetic resonance technology, which is incredibly powerful, together with X-ray ... and we found that the sum of magnetic resonance and X-ray turned out to be greater than just its constituent parts put together because new information is unlocked that's not available to either X-ray or MR alone. Schultz: When we make a scan, we're looking for where does that liquid lie in this sort of three dimensional space of NMR, ah, proton content, sort of the NMR relaxation, which is something of a measurement of how sludgy a liquid is, and then the X-ray density, when we measure those three parameters we find that benign liquids and threat liquids separate
00:01:52 real nicely in this space and we can detect them. James Hunter: Normally an experimental system takes a lot of work, a lot of things don't work right, you eventually get it working, this was very smooth, it worked very well ... just the ease with which we got it working was remarkable. Espy: I am amazed at how good it works, personally, we've been able to look at a really broad class of explosives, we've been able to look through all kinds of packaging, we've unlocked this new parameter that is based not just on the volume or the density or even the MR properties alone but this kind of multidimensional space that includes this phenomenon of actual proton content. Schultz: Our objective was to come up with a system, where without any intervention by
00:02:42 the operator, we could make a decision and say this is a threat liquid, or this is a liquid you can let pass. So, for an end user, what we really want to have is something not much more than red light green light, either this is bad, or you can let this go. Espy: I think the technology has, at least in our minds, in this proof of concept demonstration, has really proven how strong it can be. And so the hope is that we will be able to more seamlessly integrate the X-ray detector and X-ray source, which can be quite small, into the existing footprint of the bottle screener and keep the device small and inexpensive. Hunter: You can buy a smaller X-ray system off the shelf, it's a lot cheaper, there's
00:03:26 really no question there, this sort of gives you a feel for, they really don't have to be that big. Schultz: Put that inside the box, put the X-ray detector inside the box, and there's really not much more that needs to be done than that to have a scanner that could, that could provide this combined X-ray NMR scanning in an airport.