Measurement of three-dimensional lung tree structures using
computed tomography.
Wood, Susan A., Elias A. Zerhouni, John D. Hoford, Eric A. Hoffman,
Wayne Mitzner.
Departments of Radiology and Environmental Health Sciences, The
Johns Hopkins Medical Institutions, Baltimore, MD 21205, Hospital of
the University of Pennsylvania, Philadelphia, PA, Department of
Radiology, The University of Iowa Hospitals and Clinics, Iowa City,
IA
APStracts 2:0361A, 1995.
A method was devised to computationally segment and measure three
-dimensional pulmonary trees in situ . Bronchi and pulmonary vessels
were computationally extracted from volumetric computed tomography
(CT) data based on radio-opacity differences between airway wall and
airway lumen, and between blood and parenchyma, respectively. The
tree was reduced to a central axis to facilitate measurement of
branch segment length and angle. Cross sectional area was measured on
a reconstructed CT slice perpendicular to this central axis. The
method was validated by scanning two Plexiglas phantoms and an intact
lung. Reconstructed diameters in the phantoms were accurate for
branches greater than 2mm. In the lung airway branches between 1-2mm
in diameter were often unresolved when their angle of orientation
with respect to the axis of the scanner was greater than 45 degrees .
However, if a branch was resolved, its reconstructed diameter was
little affected by orientation. This method represents a significant
improvement in the analysis of complex pulmonary structures in three
dimensions.
Received 27 January 1995; accepted in final form 3 August 1995.
APS Manuscript Number A108-5.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 24 August 1995.