title: Imaging of pulmonary emphysema: a pictorial review.
abstract: The term 'emphysema' is generally used in a morphological sense, and therefore imaging modalities have an important role in diagnosing this disease. In particular, high resolution computed tomography (HRCT) is a reliable tool for demonstrating the pathology of emphysema, even in subtle changes within secondary pulmonary lobules. Generally, pulmonary emphysema is classified into three types related to the lobular anatomy: centrilobular emphysema, panlobular emphysema, and paraseptal emphysema. In this pictorial review, we discuss the radiological--pathological correlation in each type of pulmonary emphysema. HRCT of early centrilobular emphysema shows an evenly distributed centrilobular tiny areas of low attenuation with ill-defined borders. With enlargement of the dilated airspace, the surrounding lung parenchyma is compressed, which enables observation of a clear border between the emphysematous area and the normal lung. Because the disease progresses from the centrilobular portion, normal lung parenchyma in the perilobular portion tends to be preserved, even in a case of far-advanced pulmonary emphysema. In panlobular emphysema, HRCT shows either panlobular low attenuation or ill-defined diffuse low attenuation of the lung. Paraseptal emphysema is characterized by subpleural well-defined cystic spaces. Recent topics related to imaging of pulmonary emphysema will also be discussed, including morphometry of the airway in cases of chronic obstructive pulmonary disease, combined pulmonary fibrosis and pulmonary emphysema, and bronchogenic carcinoma associated with bullous lung disease.
authors.affiliation: Department of Radiology, Shiga University of Medical Science, Seta-Tsukinowa, Otsu, Shiga 520-2192, Japan. masashi@belle.shiga-med.ac.jp
authors.forename: Masashi
authors.initials: M
authors.lastname: Takahashi
authors.forename: Junya
authors.initials: J
authors.lastname: Fukuoka
authors.forename: Norihisa
authors.initials: N
authors.lastname: Nitta
authors.forename: Ryutaro
authors.initials: R
authors.lastname: Takazakura
authors.forename: Yukihiro
authors.initials: Y
authors.lastname: Nagatani
authors.forename: Yoko
authors.initials: Y
authors.lastname: Murakami
authors.forename: Hideji
authors.initials: H
authors.lastname: Otani
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Murata
mesh_terms: D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging*; D011656:Pulmonary Emphysema / Q000145:classification / Q000000981:diagnostic imaging*; D015203:Reproducibility of Results; D014057:Tomography, X-Ray Computed / Q000379:methods*