“The worst thing is to have pain somewhere in your body and have no answer for it,” Potter says. In the 1990s, Potter started using MRI to get a better look at ailing joints only to face a new problem: metal joints, plates, and screws produced magnetic artifacts, which obscured a critical part of the image where the implant meets the tissue. She experimented with magnetic field settings, pushing the MRI machine to its limit. “Every single day I would look at images side by side and scratch my head trying to figure out why Mrs. Jones had knee pain,” Potter says. “But the machine can only go so far before it cries uncle and says ‘Sorry, Hollis, I can’t do any more for you.’”
Dr. Hollis Potter with GE’s Kevin Koch: “I didn’t want an ivory tower physicist being locked up in Waukesha,” says Dr. Potter (right).
As the population ages, the problem could crop up more and more. Recent studies estimated that there are more than 1 million knee and hip replacements surgeries performed in the U.S. and 250,000 in Europe.
In 2008, Potter decided that she needed a physicist to make progress. She gathered her 10 years of patient data and started knocking on industry doors. “I went to MRI manufacturers, went through my data, and showed [them] what we had found,” Potter says. “GE was willing to step up to the plate, roll up their sleeves, and try to solve this problem through imaging.”
Potter’s luck was about to turn. GE Healthcare in Waukesha, Wisconsin, had just hired Kevin Koch, a young physicist with a doctorate from Yale. “It was methods that I developed during my Ph.D. that allowed me to model the magnetic field distortions that the metals were introducing,” Koch says.
Potter was skeptical, at first. “I didn’t want an ivory tower physicist being locked up in Waukesha,” she said. “I asked him to come out and he spent a lot of time going through my data. I had him meet with orthopedic surgeons and understand how frustrated they are. I had him meet with the patients.”
Koch sympathized with the doctor. “She was very patient in the beginning,” he says. “I am sure that she wanted results and I was showing her physics explaining where the image artifacts were coming from.”
Before long, the team got their first break and filed their first patent. Koch wrote software that could predict distortions in the magnetic field and used it to correct the distorted images. But the approached turned out to be a blind alley. “It was not robust enough,” Koch says. “It was a little bit deflating.”
But then, about nine months into their research, Koch hit on another solution. He found a new way to capture the magnetic resonance signal. Rather than building the image from two-dimensional slices, kind of like reassembling a salami, Koch started adding up an arbitrary collection of 3-D blocks, or bins. The method, a set of software instructions that can work on any MRI machine, allowed the team to take the same image at multiple frequencies and fix the distortions. “It really opened up our eyes,” Potter says.
Potter says that the system, which GE calls MAVRIC SL, allows her to see damaged tissue around “MR conditional implants,” but also nerve impingement, the integrity of joints and bones fortified with stainless plates and screws, and other medical issues. “People with a recalled implant can come in and find out if their implant is at risk,” Potter says. “Whether they are symptomatic or not, they are worried about what’s happening inside their body.”
Potter says that her hospital has already imaged 3,000 patients with MAVRIC SL. She said that her work with Koch was “a perfect example of a collaboration between an academic site and an industry.”
“It gives people an answer for their pain,” Potter said. “From an emotional standpoint of dealing with illness, that’s huge.”
Now You See Me: This 65-year old patient developed severe pain lasting several months after a total hip replacement three years earlier. Unlike X-ray and conventional MRI images, MAVRIC SL showed clear evidence of an abnormal response indicative of an adverse tissue reaction. The patient was indicated for a revision surgery. Credit: Courtesy of Hospital for Special Surgery *
*These images were generated using the MAVRIC SL software feature and are representative of the quality of images that users should expect to generate. However, GE Healthcare is not always able to confirm whether the images are of MR Conditional implants or whether scanning was in accordance with the implant's instructions for use. MAVRIC SL should only be used with MR Conditional implants and within the MR conditions specified for those implants.
The reason why you'll have those uprights there is to help
ReplyDeleteforestall excessive aspect to aspect and front to back movements that will
cause your knee pain or instability to sky rocket! generally, once people have
any level of knee pain or instability you'll got to trust the motions that your
knee goes through.
This is health info. though we have a tendency to believe the advantages of knee support, this is often not medical recommendation. it's necessary to talk to your doctor concerning medical recommendation that pertains to your specific state of affairs.
ReplyDelete