ABSTRACT

The term interstitial lung disease (ILD) refers to more than 200 chronic lung disorders that are characterized by scarring (i.e., fibrosis) and/or inflammation of the interstitium, the tissue between the air sacs of the lungs (alveoli). However, many of the disorders classified as ILD also involve other lung compartments so the more general term diffuse parenchymal lung disease (DPLD) is often used. Although ILD is a heterogeneous group of histologically different diseases, most of them have rather similar clinical presentations. ILDs usually cause lung tissue to permanently lose the ability to breathe and carry oxygen into the bloodstream. The most common symptoms are exertional dyspnea, persistent nonproductive cough, dry squeaks, crackles, finger clubbing, wheezing, loss of appetite, and fatigue. These symptoms may refer to different ILDs and even resemble other lung conditions or medical problems. ILD accounts for 15% of all cases seen by pulmonologists [1] and can be caused by (1) long-term exposure to hazardous materials (e.g., asbestos, fumes, and gases), (2) certain drugs or medications, (3) infections, (4) genetic abnormalities, and (5) autoimmune diseases, such as rheumatoid arthritis. In most cases, however, the causes remain unknown and the lung manifestations are described as idiopathic interstitial pneumonia (IIP). In 2002, an international multidisciplinary consensus, including the American Thoracic Society and the European Respiratory Society, proposed a classification for IIPs [2]

CONTENTS

6.1 Introduction ........................................................................................................................ 175 6.2 CAD for ILDs ...................................................................................................................... 178

6.2.1 Lung Segmentation in Presence of ILD .............................................................. 179 6.2.1.1 Lung Field Segmentation ....................................................................... 180 6.2.1.2 Bronchovascular Segmentation ............................................................ 183

6.2.2 ILD Pattern Quantification ................................................................................... 186 6.2.3 Differential Diagnosis ........................................................................................... 194

6.3 Discussion ........................................................................................................................... 195 6.4 Conclusion .......................................................................................................................... 196 References ..................................................................................................................................... 197

in order to establish a uniform set of definitions and criteria for their diagnosis. Figure 6.1 depicts the aforementioned classification as reproduced and modified by Wells et al. [3].