The goal of Lung Tissue Resource Consortium (LTRC) is to improve the management of diffuse lung diseases through a
better understanding of the biology of Chronic Obstructive Pulmonary Disease (COPD) and fibrotic interstitial lung
disease (ILD) including Idiopathic Pulmonary Fibrosis (IPF). Participants are subjected to a battery of tests including
tissue biopsies, physiologic testing, clinical history reporting, and CT scanning of the chest. The LTRC is a repository
from which investigators can request tissue specimens and test results as well as semi-quantitative radiology reports,
pathology reports, and automated quantitative image analysis results from the CT scan data performed by the LTRC core
laboratories. The LTRC Radiology Core Laboratory (RCL), in conjunction with the Biomedical Imaging Resource
(BIR), has developed novel processing methods for comprehensive characterization of pulmonary processes on
volumetric high-resolution CT scans to quantify how these diseases manifest in radiographic images. Specifically, the
RCL has implemented a semi-automated method for segmenting the anatomical regions of the lungs and airways. In
these anatomic regions, automated quantification of pathologic features of disease including emphysema volumes and
tissue classification are performed using both threshold techniques and advanced texture measures to determine the
extent and location of emphysema, ground glass opacities, "honeycombing" (HC) and "irregular linear" or "reticular"
pulmonary infiltrates and normal lung. Wall thickness measurements of the trachea, and its branches to the 3rd and
limited 4th order are also computed. The methods for processing, segmentation and quantification are described. The
results are reviewed and verified by an expert radiologist following processing and stored in the public LTRC database
for use by pulmonary researchers. To date, over 1200 CT scans have been processed by the RCL and the LTRC project
is on target for recruitment of the 2200 patients with 1800 CT scans in the repository for the 5-year effort. Ongoing
analysis of the results in the LTRC database by the LTRC participating institutions and outside investigators are
underway to look at the clinical and physiological significance of the imaging features of these diseases and correlate
these findings with quality of life and other important prognostic indicators of severity. In the future, the quantitative
measures of disease may have greater utility by showing correlation with prognosis, disease severity and other
physiological parameters. These imaging features may provide non-invasive alternative endpoints or surrogate markers
to alleviate the need for tissue biopsy or provide an accurate means to monitor rate of disease progression or response to
therapy.
Diffuse lung diseases, such as idiopathic pulmonary fibrosis (IPF), can be characterized and quantified by analysis
of volumetric high resolution CT scans of the lungs. These data sets typically have dimensions of 512 x 512
x 400. It is too subjective and labor intensive for a radiologist to analyze each slice and quantify regional
abnormalities manually. Thus, computer aided techniques are necessary, particularly texture analysis techniques
which classify various lung tissue types. Second and higher order statistics which relate the spatial variation of
the intensity values are good discriminatory features for various textures. The intensity values in lung CT scans
range between [-1024, 1024]. Calculation of second order statistics on this range is too computationally intensive
so the data is typically binned between 16 or 32 gray levels. There are more effective ways of binning the gray
level range to improve classification. An optimal and very efficient way to nonlinearly bin the histogram is to use
a dynamic programming algorithm. The objective of this paper is to show that nonlinear binning using dynamic
programming is computationally efficient and improves the discriminatory power of the second and higher order
statistics for more accurate quantification of diffuse lung disease.
Idiopathic pulmonary fibrosis (IPF, also known as Idiopathic Usual Interstitial Pneumontis, pathologically) is a progressive diffuse lung disease which has a median survival rate of less than four years with a prevalence of 15-20/100,000 in the United States. Global function changes are measured by pulmonary function tests and the diagnosis and extent of pulmonary structural changes are typically assessed by acquiring two-dimensional high resolution CT (HRCT) images. The acquisition and analysis of volumetric high resolution Multi-Detector CT (MDCT) images with nearly isotropic pixels offers the potential to measure both lung function and structure. This paper presents a new approach to three dimensional lung image analysis and classification of normal and abnormal structures in lungs with IPF.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.