HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Hogg, J. C. Articles by Wright, A. C. PubMed PubMed Citation Articles by Hogg, J. C. Articles by Wright, A. C.

Micro–Computed Tomography Measurements of Peripheral Lung Pathology in Chronic Obstructive Pulmonary Disease

¹ UBC iCapture Center, St Paul's Hospital, Vancouver, British Columbia, Canada; and ² University of Pennsylvania, Philadelphia, Pennsylvania

Correspondence and requests for reprints should be addressed to James C. Hogg, M.D., Ph.D., Emeritus Professor of Pathology and Lab Medicine, iCAPTURE Center, St. Paul's Hospital, Vancouver, BC V6Z 1Y6, Canada. E-mail: jhogg{at}mrl.ubc.ca

ABSTRACT

Background: The smaller airways, < 2 mm in diameter, offer little resistance in normal lungs, but become the major site of obstruction in chronic obstructive pulmonary disease (COPD).

Objective: To examine bronchiolar remodeling and alveolar destruction in COPD using micro–computed tomography (micro-CT).

Methods: Micro-CT was used to measure the number and cross-sectional lumen area of terminal bronchioles (TB) and alveolar mean linear intercept (Lm) in 4 lungs removed from patients with very severe (GOLD-4) COPD and 4 unused donor lungs that served as controls. These lungs were inflated with air to a transpulmonary pressure (P_L) of 30 cm H₂O and held at P_L 10 cm H₂O while they were frozen solid in liquid nitrogen vapor. A high resolution CT scan was performed on the frozen specimen prior to cutting it into 2-cm thick transverse slices. Representative core samples of lung tissue 2 cm long and 1 cm in diameter cut from each slice were fixed at –80°C in a 1% solution of gluteraldehyde in pure acetone, post-fixed in osmium, critically point dried, and examined by micro-CT.

Results: A 10-fold reduction in terminal bronchiolar number and a 100-fold reduction in their minimal cross-sectional lumen area were measured in both emphysematous and non-emphysematous regions of the COPD lungs.

Conclusions: The centrilobular emphysematous phenotype of COPD is associated with narrowing and obliteration of the terminal bronchioles that begins prior to the onset of emphysematous destruction.

Key Words: COPD, small airway obstruction • termination bronchioles, reduction of • emphysematous destruction