IMPERIAL COLLEGE SELECTS 3D IMAGING SYSTEM FOR NEW RESEARCH PROJECTS

Contax Ltd - UK

16 September 2004

Imperial College has purchased the phoenix|x-ray v|tome|x computed tomography* system from automation specialist, Contax Ltd, to assist in its study into the characteristics and three dimensional (3D) structure of structural and biomaterials.

The v|tome|x will be used by over a dozen academics to provide new insight into understanding complex 3D interactions of materials systems. This will comprise a number of projects including: characterising rock for improved oil extraction; studying the fatigue behaviour of aerospace materials; studying the characteristics of titanium bio-implants used in dental and orthopaedic work; and studying the growth of tissue on scaffold materials in vitro*.

The purchase of the v|tome|x system was funded by The Science Research Investment Fund (SRIF)*, a joint initiative by the Office of Science and Technology (OST) and the Department for Education and Skills (DfES). In total over £12 million has been spent to refurbish and restock the research and teaching area laboratories within the Department of Materials at Imperial College from various sources.

Explained Dr Peter Lee, Reader in Materials Processing at Imperial College, "We needed to study biomaterials in 3D and investigated the market for a suitable system. Our main criteria was that it offered a capability and could resolve structures at the near micron level in 3D. The v|tome|x system is allowing us to see structures routinely using 3 micron voxels (volume pixels).

"Following our review, we identified the phoenix|x-ray v|tome|x as the only system to meet our specification within our budget. It offered a better resolution than its competitors and was able to provide the 3D facility that we required."

The v|tome|x can produce a detailed three-dimensional radioscopic visualisation of the sample that can be inspected from all angles in tomographic slices and sections. Unlike 2D, CT can display overlapping parts separately. For long objects, the cross-section becomes accessible at any position along the axis. The tomographic images are generated using SIXTOS data acquisition and reconstruction software.

The system uses a, highly stable, X-ray tube with an interchangeable nano and microfocus columns developed by phoenix|x-ray specifically for CT. The microfocus column has a maximum high voltage of 160kV and allows tomographic 3D as well as conventional 2D inspection. The CT tube in combination with the 16-bit high-contrast detector enables image resolution of down to 3 micron voxel (volume pixel). The visualisation software enables a host of complex facilities including colour filters, morphological segmentations, surface modelling and measurements.

One of the research projects at Imperial College lead by Drs Julian Jones and Molly Stevens involves growing tissue scaffolds that could potentially provide replacement bone for osteoporosis sufferers.

Commented Dr Lee, "At present, if a major bone - such as the femur - is fractured, then the joint will be replaced with a titanium rod. However, artificial joints deteriorate and often fail before the end of the patient's life. As the titanium used in the artificial joint is stiffer than the bone it shields some of the bone from applied stress. Without stress, the bone will weaken, exacerbating the problem."

Research carried out by Imperial College will seed osteogenic cells (ideally taken from the patient) on a scaffold, which will stimulate the cells to form new bone in vitro in the shape of the scaffold.

Continued Dr Lee, "The v|tome|x will be used to examine the tissue scaffold construct through the stages of growth. The end goal is to grow new bone outside the body to a sufficient stage where it can be implanted back into the patient's defect site and quickly begin to bear loads. Once in situ, the scaffold should bond to the host bone and resorb at the same rate at which new bone grows. This will then regenerate the host bone, eliminating the need for a hip or other artificial limb replacement. The images provided by the highly resolving CT system are crucial to this research being carried out in the Biomaterials group at Imperial," he added.

Commenting on the service received from Contax, Dr Lee said, "Contax has helped us at every stage. They have been highly responsive and have continually taken on board our suggestions and improved the system to match our requirements. The system was installed and up and running within a week, and we have been very happy with their support."