Identification of Occult Parechymal Disease Such as Emphysema or Airway Disease Using Screening Computed Tomography

• Published in: Chronic obstructive pulmonary disease Vol. 7; no. 2; pp. 117 - 125
• Main Authors: Tsushima, Kenji, Sone, Shusuke, Fujimoto, Keisaku, Kubo, Keishi, Morita, Satoshi, Takegami, Misa, Fukuhara, Shunichi
• Format: Journal Article
• Language: English
• Published: Philadelphia, PA Informa UK Ltd 01.04.2010; Taylor & Francis
• Subjects: Adult; Aged; Biological and medical sciences; Chronic obstructive pulmonary disease; Chronic obstructive pulmonary disease, asthma; Female; Humans; Image Processing, Computer-Assisted; Low attenuation area; Male; Medical sciences; Middle Aged; Non-smoker; Pneumology; Pulmonary Disease, Chronic Obstructive - complications; Pulmonary Disease, Chronic Obstructive - diagnosis; Pulmonary Disease, Chronic Obstructive - diagnostic imaging; Pulmonary Emphysema - complications; Pulmonary Emphysema - diagnosis; Pulmonary Emphysema - diagnostic imaging; Respiratory Function Tests; Severity of Illness Index; Smoker; Smoking - adverse effects; Smoking - physiopathology; Tomography, X-Ray Computed - methods; Visual score; Lung disease; Visual score; Radiodiagnosis; Disease; Respiratory disease; Identification; Medical screening; Non smoker; Low attenuation area; Area; Non-smoker; Low; Smoker; Medical imagery; Bronchus disease; Attenuation; Chronic obstructive pulmonary disease; Computerized axial tomography; Emphysema
• ISSN: 1541-2555; 1541-2563; 1541-2563
• DOI: 10.3109/15412551003631717

ABSTRACT Rationale: Chronic obstructive pulmonary disease (COPD) is a major public health problem. This study was performed to determine whether the low attenuation area (LAA) and visual score provided by low-dose computed tomography (CT) can be used to detect occult parenchymal disease, such as insidious COPD. Methods: Each participant underwent low-dose CT scan and pulmonary function tests. The LAA% of the corresponding lung area was calculated. The cut-off level between the normal lung density area and LAA was defined as -960 HU, and the severity of emphysematous change (visual score) and LAA% were evaluated on three same chest CT slices obtained at full inspiration. Results: Forty-eight of 2,247 individuals including 1058 non-smokers and 1189 smokers were diagnosed with COPD. Chest CT findings in individuals diagnosed with COPD showed centrilobular emphysema (50%), however, 17 of the subjects diagnosed with COPD had normal screening CT findings. Thirty-one subjects diagnosed with COPD showed a positive visual score, and 27 individuals with COPD showed LAA% of more than 30. Nine of 17 subjects with a negative visual score showed LAA% of more than 30. The visual score in smokers was significantly higher than that of non-smokers. The lung function in smokers was lower than that of non-smokers. Smokers also showed higher frequencies of chest CT abnormalities. Conclusion: Low-dose CT scans detected LAA and a positive visual score before COPD associated with an impaired lung function develops. Smokers with normal spirometry had a potential to develop an airflow obstruction accompanied with abnormal CT findings.