AirQuant - Quantification of airway tapering, analysis of chest X-ray CT

The goal of this project is to come up with a more objective method to measure the severity of structural lung diseases such as cystic fibrosis and idiopathic pulmonary fibrosis. In these diseases, the airways dilate and worsen with disease progression (bronchiectasis). Currently, the standard for measuring lung diseases that affect the airway structure are by breath function tests which are insensitive. This means that large cohorts of patients are necessary to measure the effects of new drugs. This in turn drives up the price of new drugs. In August 2019 NHS Scotland couldn’t afford new Cystic Fibrosis drugs that came with a high price tag. It is therefore necessary to establish a more precise measure to reduce drug development costs.

An automated pipeline based on Quan et. al. 2018* to measure the tapering rate of all airways given an airway segmentation and CT has been produced. The pipeline considers the cross-sectional area at successive intervals from the carina to peripheral end along the airway, identifying false measurements due to bifurcations. An exponential curve is then fit to the remaining area measurements, computing a tapering rate. Measuring not just the inner airway taper rate but also the airway wall taper rate. As the airway lumen is often plugged in Cystic Fibrosis, the measurement of an inner taper rate is not feasible. This gives us a direct objective measure of the geometry of the airway and could help to precisely ascertain disease severity in structural airway diseases.