Touching Lives - March 2009
Crystal clear - research solves the scanning dilemma
From a small filling in a tooth to a large plate inserted to mend a broken bone, millions of us have metal implants of some kind. The bad news is that they get in the way when it comes to using modern scanning techniques, disrupting the X-ray beams and making the normally detailed 3-D images from a CT scanner unclear, subsequently hindering diagnosis. But a breakthrough by a team of researchers in Oxford promises to make scans crystal clear, marking a huge leap forward in ending the problem of blurred scan images.
New software Dr Julian Liu and the team have been working on metal implants and CT scanning for several years thanks to Action Medical Research funding. They have developed new software based on complicated mathematics to dramatically improve CT images involving metal implants – even large plates and screws – anywhere in a patient’s body.
The benefits are potentially enormous and talks are now underway with industry to further develop the technology and ultimately make it available to all hospitals, UK-wide and globally.
Dr Liu, based at the John Radcliffe Hospital, Oxford University, says: “There was previously no way to get a clear image if there was any kind of metal implant in the area to be scanned. Something as small as a single filling in a tooth could cause problems and the presence of metal made it very hard to accurately assess patients after surgery. It could also get in the way when diagnosing conditions such as cancer.
“Metal distorts the images CT scanners produce, causing a characteristic ‘streaking’, and the problem of how to get clearer pictures had been studied worldwide for about 30 years.”
The new software developed by the team eliminates the streaks and ‘dark areas’ caused by metal, even when there are several separate screws and plates in a small area.
An additional and unexpected benefit of the new technique is that as well as better images, it uses X-rays more efficiently and significantly reduces the risk of ionising radiation, protecting patients from the risk of cancer.
Dr Liu says: “It is a breakthrough with enormous potential, but rolling it out across all hospitals can’t happen overnight. It means new protocols for radiographers and other staff, and demands detailed talks with industry about developing the software and making it commercially available. It is hugely exciting; we have a method that eliminates a longstanding problem and which will help surgeons to plan operations more accurately.
“Without the funding we have received from Action Medical Research over the past six years this would have been impossible. The charity’s continued support has been critical in our success.”
Did you know?
A CT (computed tomography) scanner is a special kind of X-ray machine. It uses X-rays, but instead of sending out a single X-ray through the body, several beams are sent from different angles, making CT scans far more detailed. The information from the two-dimensional computer images can be reconstructed to produce three-dimensional images by the most advanced scanners.
Thank you to The Rosetrees Trust, and other trusts who wish to remain anonymous, for supporting this work.