The Australian National University is leading a new study that has the potential to revolutionise 3D medical imaging as well as make screening for early signs of disease much cheaper and safer.
According to a recent report, the research team, which involved the European Synchrotron Radiation Facility and Monash University, discovered a promising way to significantly lower doses of X-rays.
The team built upon an unconventional imaging approach known as “ghost imaging” to take 3D X-ray images of an object’s interior that is opaque to visible light.
The study, according to the lead researcher, was the first to achieve 3D X-ray imaging using the ghost imaging approach.
This can potentially make 3D medical imaging much cheaper, safer and more accessible.
The advantage of using the ghost imaging technique for 3D imaging is that most of the X-ray dose is not even directed towards the object that needs to be captured.
Too much radiation from medical x-ray imaging can increase cancer risk.
This limits how often patients can be tested with CT systems, 3D mammography for breast cancer screening and other 3D X-ray approaches.
Instead of using an X-ray camera, the approach utilises a sensor. Thus, this makes the 3D medical imaging setup much cheaper.
The proof-of-concept approach took a 3D ghost image of a simple object of 5.6mm diameter at a relatively low resolution of about 0.1mm.
A new ghost imaging measurement system was devised by the team. It used a series of X-ray beams with patterns.
Each beam was then split into two identical beams. The pattern was recorded in the primary beam, which acted as a reference since it never passed through the object that the researchers were imaging.
The secondary beam passed through the object, with only the total X-ray transmission measured by a single sensor.
A computer was then used to create a 2D X-ray projection image of the object from these measurements.
This process was repeated with the object at different orientations to construct a 3D image.
The most important innovation was to extend this 2D concept to achieve 3D imaging of the interior of objects that are opaque to visible light.
3D X-ray ghost imaging, or ghost tomography, is a completely new field, so there is an opportunity for the scientific community and industry to work together to explore and develop this exciting innovation.
A co-researcher from Monash University likened the team’s achievement to the early day of electron microscopes. Back then, it could only achieve a magnification of 14 times.
This result was not as good as could be obtained with even the crudest of glass lenses using visible light.
However, the microscope using electrons rather than light had the potential, which was realised only after decades of subsequent development, to see individual atoms, which are much tinier than an ordinary microscope, using visible light, can see.