Quantifying Airway Dilatation in the Lungs from Computed Tomography

Non CF bronchiectasis and idiopathic pulmonary fibrosis (IPF) are pulmonary diseases characterised by the abnormal and permanent dilatation of the airways. Computed tomography (CT) is used in clinical practice to diagnose and monitor patients with the disease. Currently, analysis of the scans is performed by manual inspection and there is no established computerised method to quantify the enlargement of airways. I developed a pipeline to quantify the cross-sectional area for a given airway track. Using an airway segmentation, my proposed algorithm measures the area at contiguous intervals along the airway arclength from the Carina to the most distal point visible on CT. I showed the use of the data generated from the pipeline in two applications. First, I proposed a novel tapering measure as the gradient of a linear regression between a logarithmic area against the arclength. The measurement was applied to airways affected by bronchiectasis. Second, I used Bayesian Changepoint Detection (BCD) with the area measurements to locate the progression of IPF along the airway track. The proposed pipeline was applied to a set of clinically acquired scans. I show a statistical difference (p = 3.4×10−4 ) in the tapering measurement between bronchiectatic (n = 53) and controlled (n = 39) airways. In addition, I report a statistical difference (p = 7.2×10−3 ) in the change in measurement between airways remaining healthy (n = 14) and airways that have become bronchiectatic (n = 5). I show the tapering measurement is reproducible independent to voxel size, CT reconstruction, and radiation dose. Using BCD, I show on simulated data (n = 14) my proposed method can detect the progression of IPF within 2.5mm. Finally, using results from BCD, I present a novel measure of IPF progression as the percentage volume change in the diseased region of the airways

Airway tapering: an objective image biomarker for bronchiectasis

Purpose: To estimate airway tapering in control subjects and to assess the usability of tapering as a bronchiectasis biomarker in paediatric populations. Methods: Airway tapering values were semi-automatically quantified in 156 children with control CTs collected in the Normal Chest CT Study Group. Airway tapering as a biomarker for bronchiectasis was assessed on spirometer-guided inspiratory CTs from 12 patients with bronchiectasis and 12 age- and sex-matched controls. Semi-automatic image analysis software was used to quantify intra-branch tapering (reduction in airway diameter along the branch), inter-branch tapering (reduction in airway diameter before and after bifurcation) and airway-artery ratios on chest CTs. Biomarkers were further stratified in small, medium and large airways based on three equal groups of the accompanying vessel size. Results: Control subjects showed intra-branch tapering of 1% and inter-branch tapering of 24–39%. Subjects with bronchiectasis showed significantly reduced intra-branch of 0.8% and inter-branch tapering of 19–32% and increased airway–artery ratios compared with controls (p < 0.01). Tapering measurements were significantly different between diseased and controls across all airway sizes. Difference in airway–artery ratio was only significant in small airways. Conclusion: Paediatric normal values for airway tapering were established in control subjects. Tapering showed to be a promising biomarker for bronchiectasis as subjects with bronchiectasis show significantly less airway tapering across all airway sizes compared with controls. Detecting les

Tapering Analysis of Airways with Bronchiectasis

Bronchiectasis is the permanent dilation of airways. Patients with the disease can suffer recurrent exacerbations, reducing their quality of life. The gold standard to diagnose and monitor bronchiectasis is accomplished by inspection of chest computed tomography (CT) scans. A clinician examines the broncho-arterial ratio to determine if an airway is brochiectatic. The visual analysis assumes the blood vessel diameter remains constant, although this assumption is disputed in the literature. We propose a simple measurement of tapering along the airways to diagnose and monitor bronchiectasis. To this end, we constructed a pipeline to measure the cross-sectional area along the airways at contiguous intervals, starting from the carina to the most distal point observable. Using a phantom with calibrated 3D printed structures, the precision and accuracy of our algorithm extends to the sub voxel level. The tapering measurement is robust to bifurcations along the airway and was applied to chest CT images acquired in clinical practice. The result is a statistical difference in tapering rate between airways with bronchiectasis and controls

Diseases of the Chest, Breast, Heart and Vessels 2019-2022

This open access book focuses on diagnostic and interventional imaging of the chest, breast, heart, and vessels. It consists of a remarkable collection of contributions authored by internationally respected experts, featuring the most recent diagnostic developments and technological advances with a highly didactical approach. The chapters are disease-oriented and cover all the relevant imaging modalities, including standard radiography, CT, nuclear medicine with PET, ultrasound and magnetic resonance imaging, as well as imaging-guided interventions. As such, it presents a comprehensive review of current knowledge on imaging of the heart and chest, as well as thoracic interventions and a selection of "hot topics". The book is intended for radiologists, however, it is also of interest to clinicians in oncology, cardiology, and pulmonology

Diseases of the Chest, Breast, Heart and Vessels 2019-2022

This open access book focuses on diagnostic and interventional imaging of the chest, breast, heart, and vessels. It consists of a remarkable collection of contributions authored by internationally respected experts, featuring the most recent diagnostic developments and technological advances with a highly didactical approach. The chapters are disease-oriented and cover all the relevant imaging modalities, including standard radiography, CT, nuclear medicine with PET, ultrasound and magnetic resonance imaging, as well as imaging-guided interventions. As such, it presents a comprehensive review of current knowledge on imaging of the heart and chest, as well as thoracic interventions and a selection of "hot topics". The book is intended for radiologists, however, it is also of interest to clinicians in oncology, cardiology, and pulmonology