Sung Shine Shim, Presenter: Nothing to Disclose

Mark L. Schiebler MD, Abstract Co-Author: Shareholder, Cellectar Biosciences, Inc

Ronald L. Sorkness, Abstract Co-Author: Nothing to Disclose

Nizar Jarjour, Abstract Co-Author: Nothing to Disclose

Jeffrey P. Kanne MD, Abstract Co-Author: Research Consultant, Perceptive Informatics, Inc

Sean B. Fain PhD, Abstract Co-Author: Research Grant, General Electric Company Research Consultant, Marvel Medtech, LLC

We sought to determine if asthmatics show differential airway morphologic changes based on the sizes of their respective bronchial generation and degree of collapse at end expiration using post processing of their HRCT images.

VIDATM software was used to analyze 185 severe asthma research program (SARP) patients HRCT scans by their respective bronchial generations. The data was reviewed for airway remodeling in normal volunteers (33), non-severe asthmatics (63) and severe asthmatics (89).  A total of 4501 airways were analyzed at both FRC and TLC. The following generations (total number) were reviewed: 1st (183), 2nd (365), 3rd (542), 4th (1538), 5th (1575) and 6th (298). We analyzed wall area percentage (WA%) and wall thickness percentage (WT%), and deltalumen for each generation between non-severe, severe and normal subjects. The SPSS statistical package was used to determine the significance of variation between these groups at each generation of bronchi.  

We found that greater WT% and WA% was seen in the severe asthma group than in the non-severe asthma group. Quantitatively, WA% and WT% showed a steady increase  through each bronchial generation. In normal subjects, there is a gradual change in airway deltalumen from generation 1st to 6th. However, in asthmatics (non-severe and severe), we found that the deltalumen was greater in the 3rd and 4th generation airways (p value<0.001) than the 5th and 6th. The maximal difference in deltalumen in asthmatics was found at the 4th generation.  

1. Deltalumen at 3rd and 4th generation airways in the SARP cohort was significantly increased when compared to that of control group. 2. WA% and WT% showed a steady increase in values from central to the more distal airways for all groups. 3. Each generation of airway of the asthmatic subjects, compared with those of the normal subjects, behaved differently. In asthmatics, the deltalumen showed an increase for 1-4th generation and then was found to decrease in the more distal airways (5-6th generation). However,  in the normal cohort, there was a steady increase in this parameter.      

These data show that there is a loss of the normal graded collapse of the asthmatic airway at FRC. This change in airway compliance may play a role in the limitation of FEV1 in these individuals and may promote air trapping in the secondary lobule.  

Shim, S, Schiebler, M, Sorkness, R, Jarjour, N, Kanne, J, Fain, S, Post-processing of 3rd and 4th Generation Bronchial Luminal Cross-sectional Area at End-expiration Significantly Differs in Asthmatics: A Newly Discovered Biomechanical Difference Found in Severe Asthma Research Program (SARP) Subjects.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14006611.html