A new 3D gamma radiation imaging system could improve the diagnosis of lung disease and aid research into its effect on the body.
A team of doctors, scientists and engineers at Southampton University has developed the system, which produces 3D computer images of the lungs, and has now begun using it to study different conditions.
The system combines a model of the lungs created using X-ray computed tomography (CAT scanning), with a 3D map of how a radioactive aerosol spreads through the lungs once it is inhaled, which is built using two gamma radiation detectors.
The aerosol is made from an isotope of technetium, a common material used in medical imaging, which acts as a marker or label inside the lungs, said research leader Prof Joy Conway of Southampton’s Faculty of Health Sciences.
‘We can then watch to see where it is deposited and if parts of the lung are not receiving any of the aerosol at all,’ she told The Engineer. ‘We could also watch to see if the particle moves up the lung and is cleared from the lung in the right way.’
This will enable doctors to identify and study diseases such as cystic fibrosis, where mucus blocks the lungs and so prevents the spread of the technetium marker, and primary ciliary dyskinesia (PCD), which is sometimes misdiagnosed as repeated chest infections.
The researchers have already begun a study of patients with chronic obstructive pulmonary disease (COPD), a combination of chronic bronchitis and emphysema experienced by smokers, where the lungs take longer than normal to clear secretions.
A team led by Prof John Fleming and Dr Michael Bennett built the imaging system using two off-the-shelf gamma radiation detectors positioned on a circular gantry that enables them to move around the patient’s body.
Existing gamma imaging systems only produce two-dimensional pictures, which do not provide as much detail. ‘The big challenge is in handling three-dimensional data,’ said Conway.
‘Even though we have high-resolution computed tomography, we don’t have a very detailed description of the smaller airways, which we need to understand how disease progresses and whether a therapy works or not.’
The project is part of Southampton’s Respiratory Biomedical Research Unit, which was set up this year with £7.5m of funding from the National Institute for Health Research (NIHR), which co-ordinates research for the NHS.