Automated and interactive image analysis workstation for the extraction of imaging biomarkers related to chronic obstructive pulmonary disease from thoracic computed tomography scans

B.C. Lassen, M. Schmidt, E.M. van Rikxoort, B. van Ginneken, C. Jacobs, J. Kuhnigk and M. Prokop

in: Annual Meeting of the Radiological Society of North America, 2012

Abstract

BACKGROUND Chronic obstructive pulmonary disease (COPD) is a leading and rising cause of morbidity and mortality worldwide, with 12 million people in the United States currently diagnosed. An increasing number of paired inspiratory and expiratory computed tomography (CT) scans are taken of patients with COPD but clinically available workstations do not provide the tools needed for interpretation of these scans. To gain insight into the underlying pathways of COPD and monitor progression, methods to extract imaging biomarkers and visualize COPD from chest CT scans are of crucial importance. We have developed a workstation that allows visualization of inspiratory and expiratory CT simultaneously, extracts quantifiable features from both the inspiration and expiration CT related to parenchyma and airway morphology, displays the results in the scans, allows for interactive correction, and produces structured reports. The software is currently available as a research prototype and is used for the analysis of scans made for pharmaceutical trials. It is not yet commercially available and open-source licenses to not apply. METHODOLOGY/APPLICATION The workstation has the following features and workflow: When a study is sent to the workstation two preprocessing steps are performed. An elastic registration between the inspiration and expiration scans is performed to allow for linking of spatial locations between the inspiration and expiration scans. The lungs, lobes, airways, fissures, and segments are automatically segmented [1] allowing regional analysis. The preprocessing is performed offline and preloaded in the background such that a user of the workstation has the results readily available when viewing the scan. Once the preprocessing is finished the study is available for analysis in the workstation. On opening a study, the user can scroll through the inspiratory and expiratory CT simultaneously in any direction to visually inspect the scans. The results of the automatic segmentations of anatomical structures can be overlayed on the scans. In case the user is not satisfied with the segmentation results of the lungs or lung lobes the observer can correct the segmentation in a short time with an intuitive interactive correction method [2]. Once the segmentations have been approved, a range of quantifiable features can be visualized in the workstation: parenchyma features, airway features [3], and fissure completeness [4]. All relevant measurements are reported for both inspiration and expiration for the whole lung as well as per lobe and segment to allow for regional analysis. In addition, the changes between inspiration and expiration are reported. After workup of a study of a COPD patient, a structured report is produced that contains screenshots, renderings, and all requested measurements. The reports are created in HTML and PDF format, allowing them to be viewed in the workstation as well as in other environments. DEMONSTRATION STRATEGY For the exhibit an informational poster will be present that highlights the key aspects of the here proposed workstation and workflow. The underlying algorithms will be explained and the use of the analysis showcased with example scans. Attendees will be able to gain hands-on experience with the workstation, inspect the results of automatic processing, interact with the methods, and obtain structured reports of the findings.