Low-attenuation areas of the lungs on high-resolution computed tomography in asthma

Fumihiro Mitsunobu, Takashi Mifune, Kozo Ashida, Yasuhiro Hosaki, Hirofumi Tsugeno, Makoto Okamoto, Seishi Harada, Yoshiro Tanizaki

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To investigate the low-attenuation areas of the lungs (LAA) in asthma, we compared the mean lung density (MLD) and the LAA in 22 asthmatics (12 ex-smokers and 10 nonsmokers) and 13 patients with chronic obstructive pulmonary disease (COPD) by high-resolution computed tomography. The MLD and the relative area of the lung with attenuation values lower than -950 Hounsfield Units at full inspiration (inspiratory RA950) were significantly different in nonsmoking asthmatics compared to patients with COPD and asthmatics with a smoking history. The MLD and the RA950 correlated significantly with the FEV1 in all groups and with the DLco in patients with COPD and asthmatics with a smoking history but not in nonsmoking asthmatics. We concluded that the LAA in asthmatics with a smoking history indicates the presence of emphysema, but in nonsmoking asthmatics it reflects hyperinflation and nonemphysematous expiratory airflow limitation rather than emphysematous lesions.

Original languageEnglish
Pages (from-to)413-422
Number of pages10
JournalJournal of Asthma
Issue number5
Publication statusPublished - Aug 29 2001



  • Asthma
  • DL
  • FEV
  • High-resolution computed tomography
  • Low-attenuation area

ASJC Scopus subject areas

  • Pediatrics, Perinatology, and Child Health
  • Immunology and Allergy
  • Pulmonary and Respiratory Medicine

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