Washington University. The Washington University site, headed by Mario Castro, MD, MPH, leads an ancillary study to the SARP sites. The overall goal of this project is to better understand whether an imaging modality using multidetector-row CT (MDCT) chest can provide a noninvasive measure of airway remodeling in asthma. This Imaging component of SARP includes an Imaging Core (University of Iowa), Morphology Core (Washington University & University of Pittsburgh), and a Biostatistical Core (Washington University). In this project, patients with severe and mild asthma and normal subjects undergo MDCT chest then bronchoscopy with guided imaging to direct where endobronchial biopsies can be obtained for the optimal sampling of a remodeled airway. We propose that validating this technology in SARPII will provide a valuable, clinically useful, noninvasive measure of airway remodeling.