'Novel method to help assess lung function'
Researchers have developed a new method of analysing X ray images of lungs, which could help in the diagnosis and assessment of Chronic Obstructive Pulmonary Disease, and other lung diseases.
The team at the University of Southampton in the UK devised the method for numerically describing the complicated three dimensional structure of the lung using topology a part of mathematics designed specifically for the study of complex shapes.
Utilizing a combination of computed tomography (CT) scans, high performance computing and algorithms, the researchers computed numerical characteristics, in three dimensions, of the entire bronchial trees of 64 patients categorised in four different groups.
The groups were: healthy non-smokers, healthy smokers, patients with moderate COPD and patients with mild COPD.
COPD is a complex lung condition that involves, to various degrees, the airways (bronchi) and the lung tissue (alveoli). It results in a progressive loss of lung function. The condition affects more than 200 million people worldwide. It is the fourth leading cause of death worldwide, researchers said.
In the study, published in the journal Scientific Reports, the team analysed such features as the structure and size of the bronchial tree, the length and direction of its branches and the comparative changes in shape during deep inhalation and full exhalation.
They found that, typically, a larger more complex tree indicates better lung function and a smaller distorted tree, poorer lung function.
The researchers found that their novel method was able to accurately distinguish between the different groups of patients, the characteristics of their lung function and the different stages of their condition. It was able to identify characteristics not detectable to the naked eye.
They hope that repeating this method across a much larger database of images and combining it with other data could lead to the real world development of a valuable clinical tool for the early diagnosis of conditions like COPD and asthma. This provides a more accurate way of identifying the severity of an individual patient's condition, researchers said.
Until now, the severity of lung conditions has been assessed by using a spirometer which is a device which measures the force and amount of air a patient can exhale. Two dimensional CT images, assessed by expert specialists, who have extensive experience of examining and interpreting CT imagery, and relatively simple measures of lung density and bronchial wall thickness are also used.
Our study shows that this new method, employing topological data analysis, can complement and expand on established techniques to give a valuable, accurate range of information about the lung function of individuals," said Jacek Brodzki, a professor at the University of Southampton.
This method is a major advance in our ability to study the structural abnormalities of COPD, a complex disease that affects so many people and, sadly, results in significant morbidity and mortality," said Ratko Djukanovic, a professor at the University of Southampton.