title: Decrease in Small Pulmonary Vessels on Chest Computed Tomography in Light Smokers Without COPD: An Early Change, but Correlated with Smoking Index.
abstract: The aim of this study was to evaluate the relationship between the amount of smoking and the cross-sectional area (CSA) of small pulmonary vessels in light smokers without a diagnosis of chronic obstructive pulmonary disease (COPD).
  
  
  
  This retrospective study was approved by our institutional review board, which waived the need for informed consent from patients. The study included 34 current smokers without COPD, who were defined as light smokers based on their smoking history (≤25 pack years). The CSA of small pulmonary vessels (<5 mm2[CSA<5]) was measured on computed tomography (CT) scans, and the percentage of total CSA of the lung (%CSA<5) was calculated. The extent of emphysema was also assessed as the percentage of low attenuation area (%LAA, <-950 Hounsfield units). The correlations of %CSA<5and %LAA with pack years were determined using the Spearman rank correlation.
  
  
  
  There was a significant negative correlation between %CSA<5and pack years, whereas no significant correlation was found between %LAA and pack years. The correlations between pack years and percent predicted forced expiratory volume in 1 s (FEV1) and FEV1/forced vital capacity were not significant.
  
  
  
  The percentage of total CSA of the lung made up of small pulmonary vessels in light smokers without COPD significantly decreases with increasing amount of smoking, in contrast to emphysema measurements. This suggests that small pulmonary vessels might have been injured or might have degenerated because of smoking, and might represent an initial stage in the development of COPD.
authors.affiliation: Department of Radiology, St. Marianna University School of Medicine, 2-16-1 Sugao, Miyamae-ku, Kawasaki, Kanagawa, 216-8511, Japan. buhi_11_22@yahoo.co.jp.
authors.forename: Shinji
authors.initials: S
authors.lastname: Saruya
authors.affiliation: Department of Radiology, St. Marianna University School of Medicine, 2-16-1 Sugao, Miyamae-ku, Kawasaki, Kanagawa, 216-8511, Japan.|Department of Radiology, Graduate School of Medical Science, University of the Ryukyus, 207 Uehara, Nishihara, Okinawa, 903-0215, Japan.
authors.forename: Tsuneo
authors.initials: T
authors.lastname: Yamashiro
authors.affiliation: Department of Radiology, St. Marianna University School of Medicine, 2-16-1 Sugao, Miyamae-ku, Kawasaki, Kanagawa, 216-8511, Japan.
authors.forename: Shin
authors.initials: S
authors.lastname: Matsuoka
authors.affiliation: Department of Radiology, St. Marianna University School of Medicine, 2-16-1 Sugao, Miyamae-ku, Kawasaki, Kanagawa, 216-8511, Japan.
authors.forename: Shoichiro
authors.initials: S
authors.lastname: Matsushita
authors.affiliation: Department of Radiology, St. Marianna University School of Medicine, 2-16-1 Sugao, Miyamae-ku, Kawasaki, Kanagawa, 216-8511, Japan.
authors.forename: Kunihiro
authors.initials: K
authors.lastname: Yagihashi
authors.affiliation: Department of Radiology, St. Marianna University School of Medicine, 2-16-1 Sugao, Miyamae-ku, Kawasaki, Kanagawa, 216-8511, Japan.
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Nakajima
mesh_terms: D000328:Adult; D000368:Aged; D001808:Blood Vessels / Q000000981:diagnostic imaging* / Q000473:pathology; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008168:Lung / Q000098:blood supply* / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D009929:Organ Size; D011656:Pulmonary Emphysema / Q000000981:diagnostic imaging; D012189:Retrospective Studies; D012907:Smoking / Q000009:adverse effects*; D011795:Surveys and Questionnaires; D014057:Tomography, X-Ray Computed; D014797:Vital Capacity
keywords: COPD; Cross-sectional area; Current smokers; Pack years; Pulmonary vessels; Smoking habits