The architecture of the lung is discussed with special focus on lung parenchyma. The lung parenchyma is mainly comprised of numerous air-containing passages and intervening fine structures, corresponding to alveolar ductal lumens and alveoli, as well as alveolar septa and small pulmonary vessels occupying 10% of total parenchymal volume. The shapes and relative arrangements of alveolar ducts and alveoli are discussed in detail, which is followed by a brief description of bronchial circulation and pulmonary lymphatics.
From the *Department of Radiology, University of Fukui Faculty of Medical Sciences, Matsuoka-cho, Yoshida-gun, Fukui, Japan; and †Department of Radiology, Beth Israel Deaconess Medical Center, Boston, MA.
Reprints: Hiroto Hatabu MD, PhD, Department of Radiology, Beth Israel Deaconess Medical Center, 330 Brookline Ave., Boston, MA 02215 (e-mail: firstname.lastname@example.org).