Cambridge University scientists have developed a new method for identifying bones at risk of fracture and for monitoring the effectiveness of bone-strengthening drugs and techniques.
The method, developed by Dr Graham Treece of the Department of Engineering and Dr Ken Poole of the Department of Medicine, uses CT imaging to measure the thickness of the cortical bone, the hard outer layer of compact bone that surrounds the trabecular bone. Cortical bone thickness is an indicator of the risk of fracture.
According to Cambridge University, the work is expected to lead to advances in the treatment and management of osteoporosis, which affects one in two women and one in five men over the age of 50 in the UK.
Osteoporosis results in a decline in bone strength and thinning of the cortical bone, so that often the remaining bone is exceptionally thin by the time an individual is in their 80s. At certain key points, this thinning can lead to bones so weak that a stumble, trip or fall can lead to a fracture.
Currently, the key technology used to assess a patient’s risk of fracture is a bone mineral density test, which uses dual-energy X-ray absorptiometry (DXA) to estimate mineral levels contained in bone.
An alternative is multi-detector computed tomography (MDCT), which provides more comprehensive 3D imaging of bone structure, but not at sufficient resolution to provide accurate sub-millimetre measurement.
The method developed by Treece and Poole is claimed to increase the accuracy of cortical bone measurements to the extent that clinicians can map changes in thickness over time and produce measurements of thicknesses as low as 0.3mm.
Utilising data from a CT scan and a mathematical model of the scanning process, thousands of cortical bone measurements are obtained. This produces a 3D thickness map, which allows the identification of areas that are dangerously thin.
Successive imaging allows maps to be produced depicting changes in the cortical bone over time in all areas of the skeleton so that the progress of osteoporosis treatments can be monitored.
‘This exciting technology has the potential to improve the treatment of patients suffering from osteoporosis, as well as to support the development of new drugs,’ said Dr Andrew Walsh of Cambridge Enterprise, the university’s commercialisation group.
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