Anatomy.—The lobule is the smallest unit of lung surrounded by connective-tissue septa, as defined by Miller (78) and Heitzman et al (40). The lobule is also referred to as the secondary pulmonary lobule; it contains a variable number of acini, is irregularly polyhedral in shape, and varies in size from 1.0 to 2.5 cm in diameter. The centrilobular structures, or core structures, include bronchioles and their accompanying pulmonary arterioles and lymphatic vessels. The connective-tissue septa surrounding the pulmonary lobule—the interlobular septa, which contain veins and lymphatic vessels—are best developed in the periphery in the anterior, lateral, and juxtamediastinal regions of the upper and middle lobes. CT scans.—On thin-section CT scans, the three basic components of the lobule—the interlobular septa and septal structures, the central lobular region (centrilobular structures), and the lobular parenchyma—can be identified, particularly in disease states. Peripheral lobules are more uniform in appearance and pyramidal in shape than are central lobules (4) (Fig 35). [Fleischner Society]

http://www.radlex.org/RID/RID1361

Anatomy.—The lobule is the smallest unit of lung surrounded by connective-tissue septa, as defined by Miller (78) and Heitzman et al (40). The lobule is also referred to as the secondary pulmonary lobule; it contains a variable number of acini, is irregularly polyhedral in shape, and varies in size from 1.0 to 2.5 cm in diameter. The centrilobular structures, or core structures, include bronchioles and their accompanying pulmonary arterioles and lymphatic vessels. The connective-tissue septa surrounding the pulmonary lobule—the interlobular septa, which contain veins and lymphatic vessels—are best developed in the periphery in the anterior, lateral, and juxtamediastinal regions of the upper and middle lobes. CT scans.—On thin-section CT scans, the three basic components of the lobule—the interlobular septa and septal structures, the central lobular region (centrilobular structures), and the lobular parenchyma—can be identified, particularly in disease states. Peripheral lobules are more uniform in appearance and pyramidal in shape than are central lobules (4) (Fig 35). [Fleischner Society]

RID1361

http://www.radlex.org/RID/RID1301

secondary pulmonary lobule

RID1:RID1361

secondary pulmonary lobule

Fleischner Society

http://www.radlex.org/RID/RID1360

http://www.radlex.org/RID/RID43265