Chest ACCP Member Benefits
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Guest Access | Sign In via User Name/Password
This Article
Right arrow Full Text Free
Right arrow Full Text (PDF) Free
Right arrow Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Article Archive
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via ISI Web of Science (4)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Amirav, I.
Right arrow Articles by Grunstein, M. M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Amirav, I.
Right arrow Articles by Grunstein, M. M.
(Chest. 2001;119:1878-1885.)
© 2001 American College of Chest Physicians

Methacholine-Induced Temporal Changes in Airway Geometry and Lung Density by CT*

Israel Amirav, MD{dagger}; Sandra S. Kramer, MD and Michael M. Grunstein, MD, PhD

* From the Division of Pulmonary Medicine (Drs. Amirav and Grunstein) and Department of Radiology (Dr. Kramer), The Children’s Hospital of Philadelphia, Philadelphia, PA. {dagger} Currently at the Division of Pediatrics Pulmonology, Sieff Government Hospital, Safed, Israel.

Correspondence to: Israel Amirav, MD, Hanarkis 41 Rosh Pina, 12000 Israel; e-mail: amirav{at}012.net.il

Purpose: Electron-beam CT (EBCT) was utilized to assess the time course of changes in airways cross-sectional area (CSA) and lung density during methacholine-induced bronchoconstriction.

Materials and methods: EBCT scans (200 ms, 3-mm thickness, 2 mm increments) were obtained before (baseline) and 30 s, 2 min, and 4 min after bolus IV injection of methacholine to pigs receiving mechanical ventilation. A total of seven experiments were analyzed using custom-made image analysis software. With each challenge, five different airways and 50 lung regions of interest were studied.

Results: The time course of lung density changes paralleled the time course for CSA changes. The maximal response to methacholine, measured in terms of both CSA and lung density changes, occurred 30 s after injection. Lung density changes were unaffected by reconstruction algorithm, normal (standard) or sharp (high resolution). Overall, there was increased air content in the lung during bronchoconstriction. This effect was significantly greater at the dependent lung regions.

Conclusions: EBCT is an effective tool to assess temporal and regional changes in the lung during bronchoconstriction. Measurements of lung density during bronchoconstriction allow for assessment of peripheral changes that are beyond the CT spatial resolution of airways anatomy.

Key Words: bronchoconstriction • CT • electron beam CT • image processing • lung density • methacholine






HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 2001 by the American College of Chest Physicians.