Chapter 43 - Quantitative Imaging of the Lung

Abstract

This chapter focuses on these non-invasive quantitative measurements of lung structure specifically as they apply to lung structure and the changes involved in chronic obstructive pulmonary disease (COPD). Imaging of the lung has always played a very important role in pulmonary medicine. The advent of quantitative imaging allowed lung researchers to move beyond descriptive studies in the lung and actually apply measurements that could be applied to humans generally and disease conditions specifically. Unfortunately, pathologic techniques have some considerable drawbacks most notably that they require the tissue from either resected or autopsy specimens. The second limitation is that they are histologic examinations and because of their depth of scale require an extensive amount of work to cover a small region of the lung. However, pathology and histology are still considered the gold standard by which all other measuring devices are judged and remain the cornerstone of quantitative analysis. Medical imaging has become so popular and the introduction of the computed tomography (CT) scanner by Hounsfield has changed the way organs are looked at. An examination of CT is provided; since it is the most popular both in terms of market penetration of the CT scanner, and quantitative methodologies. The other major focus of this chapter is hyperpolarized magnetic resonance (MR) imaging since it is a growing field and potentially has some valuable insights. COPD can be divided into two separate sections based on widely accepted phenotypic expressions of the disease, emphysema and small airways disease because the exact pathogenesis of COPD is still unknown and it varies widely between individuals.