Touching Lives - November 2005
X-rayted computer technology
The apparent distance between amazing, ‘out of this world’ medicine — as practised on board the Starship Enterprise — and real world science is gradually getting smaller. Advances in computer technology have taken long-established medical procedures, such as X-rays, forward into the 21st century, allowing us a new perspective and clearer insight into the human body and the conditions that affect it.
A recently completed Action Medical Research project, headed by Oxford-based Steve Watt-Smith, is a perfect example of this. These researchers have found a way to take existing X-ray data and solve a problem that has confounded doctors for the last twenty years.
Building a 3D picture
While a simple X-ray gives a flat representation of its subject, ^CT, or computer tomography, scans help doctors to build a 3D picture of what’s going on inside the body^. A CT scanner is like a giant X-ray doughnut through which the patient passes whilst lying still on a bed. While a standard X-ray passes one single beam through the body to produce an image, CT scanners pass several beams simultaneously from different angles.
The X-rays from the beams are picked up after they have passed through the body and their strength is measured. Tissue that is less dense, such as the lung, shows a strong beam whereas denser bone tissue will only allow a weaker signal.
Computers can analyse the different results and calculate a two-dimensional picture of a cross-sectional ‘slice’ through the body showing tissues and bones. Further scans then provide enough data to build up a 3D picture.
These advances, which have combined clever computer software with existing X-ray science, have been crucial to medical teams pre and post-surgery and in the planning of biopsies.
However, despite this, a simple filling in your tooth could mean that a CT scan of your jaw would prove to be useless to a surgeon.
Not picture perfect
Unfortunately, CT scanners simply do not like metal and for the last twenty years doctors have struggled against the interference caused by metal implanted within the human body.
Fillings, hip replacements, reconstruction plates, pacemakers, even accidental impalements from nails can cause CT scans to characteristically ‘streak’ with lines that prevent an accurate assessment or diagnosis.
It becomes difficult, if not impossible, for doctors to see bone and tissue clearly — which could lead to important signs that would indicate a tumour, bony growth or even a fracture being hidden.
However, the innovative Action Medical Research team from Oxford has found a way around the problem, using complex mathematics to develop a computer programme that is well on its way to providing a solution that could be used in hospitals very soon.
Mr Watt-Smith explains, “We have tested the new software using a joint of meat from the supermarket, that had a nail embedded in it, and the difference in the quality of the images is clear. This is a huge jump forward. The next step is to trial the software on patients in a clinical setting.
“The team is going to build on this successful work with a new project grant, also funded by Action Medical Research, that will allow us to develop our software further. This will mean we can perfect the image enhancement so that its benefits can be shared worldwide in the near future.”
Mr Watt-Smith continues, “At the moment children who have had spinal or corrective surgery, and older people with knee and hip replacements would not be suitable for CT scanning. In the future we believe that any patient, young or old, will be able to have clear CT scans.
“With far greater detail available to them, doctors will be able to accurately assess the healing process and significantly improve treatment. This would be a tremendous advance in the assessment of patients following surgery.”
A grant towards the cost of this research was made by Doris Field Charitable Trust.