Scoring CT/HRCT findings among asbestos-exposed workers: effects of patient's age, body mass index and common laboratory test results

Our plain-English summary of Scoring CT/HRCT findings among asbestos-exposed workers: effects of patient's age, body mass index and common laboratory test results, by T. Vehmas, L. Kivisaari, M.S. Huuskonen, et al (European Radiology, 2005).

The study

• Authors: T. Vehmas, L. Kivisaari, M.S. Huuskonen, M.S. Jaakkola
• Journal: European Radiology
• Published: 2005;15(2):213-9
• Cited by: 19 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

We studied the effects of age, body mass index (BMI) and some common laboratory test results on several pulmonary CT/HRCT signs. Five hundred twenty-eight construction workers (age 38-80, mean 63 years) were imaged with spiral and high resolution CT. Images were scored by three radiologists for solitary pulmonary nodules, signs indicative of fibrosis and emphysema, ground glass opacities, bronchial wall thickness and bronchiectasis. Multivariate statistical analyses were adjusted for smoking and asbestos exposure. Increasing age, blood haemoglobin value and erythrocyte sedimentation rate correlated positively with several HRCT signs. Increasing BMI was associated with a decrease in several signs, especially parenchymal bands, honeycombing, all kinds of emphysema and bronchiectasis. The latter finding might be due to the suboptimal image quality in obese individuals, which may cause suspicious findings to be overlooked. Background data, including patient's age and body constitution, should be considered when CT/HRCT images are interpreted.

In plain English

This cross-sectional study examined whether age, body mass index (BMI) and three common blood tests (haemoglobin, C-reactive protein and erythrocyte sedimentation rate, ESR) were related to findings on chest CT and high resolution CT scans. The 528 construction workers (518 men, 10 women, aged 38 to 80) included 106 with an asbestosis diagnosis and 422 with bilateral pleural plaques and over 10 years of smoking. Three radiologists scored the scans independently, and analyses were adjusted for smoking and asbestos exposure. Older age was linked to more of most abnormal signs, including having lung nodules (odds ratio 1.046 per year, 95% confidence interval 1.010 to 1.084) and the fibrosis score. Higher BMI was linked to lower scores, significantly for parenchymal bands, honeycombing, all kinds of emphysema and bronchiectasis. Higher haemoglobin and ESR were significantly linked to several signs; C-reactive protein was not significantly associated with any sign. The authors suggested the BMI finding might reflect poorer image quality in heavier people, which they did not analyze in relation to BMI. They concluded that age and body constitution should be considered when reading these scans.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Cross-sectional study of CT/HRCT scores in relation to age, body mass index and blood test results
• Who was studied: 528 construction workers (518 men, 10 women, age 38 to 80, mean 63), drawn from 602 workers screened for lung cancer and evaluated for asbestos-related lung disease. The group included 106 workers with an asbestosis diagnosis and 422 workers with bilateral pleural plaques and a smoking history of more than 10 years.
• Exposure: Asbestos exposure, with no fiber types named. It was measured as duration of exposure (2 to 48 years, mean 26) and occupation (engineer, electrician, carpenter, plumber, insulator, other), used as a proxy for intensity. These were adjustment factors. The factors of interest were age, BMI, blood haemoglobin, C-reactive protein and ESR.
• Main results:
  • Across all 528 workers, advancing age was related to an increase in most abnormal CT/HRCT signs, independently of smoking and asbestos exposure. This applied especially to solitary nodules, fibrosis score, septal lines, parenchymal bands, ground glass opacities and bronchial wall thickness.
  • For solitary nodules (one or more nodules present), the odds ratio per one-year increase in age was 1.046 (95% confidence limits 1.010 to 1.084, P 0.013).
  • Increasing BMI was generally associated with a decrease in abnormal signs. This was statistically significant for parenchymal bands, honeycombing, all kinds of emphysema and bronchiectasis.
  • Higher blood haemoglobin was significantly associated with higher fibrosis score, subpleural septal lines and ground glass opacities.
  • C-reactive protein was not significantly associated with any CT/HRCT sign.
  • ESR was positively and significantly associated with the fibrosis score, subpleural septal lines, parenchymal bands, honeycombing, paraseptal emphysema, bronchial wall thickness and bronchiectasis.
  • Agreement between the radiologists varied from 0.20 (subpleural nodules) to 0.61 (subpleural curvilinear opacities).
• The authors' conclusion: The authors concluded that patient characteristics, especially age and body constitution, should be taken into account when CT/HRCT images are interpreted. They also concluded that signs of lung pathology increase with age even when smoking and asbestos exposure are controlled.
• Limitations the authors state:
  • Only ten workers were female, so the authors stated the findings should mainly be generalized to males.
  • Scoring of CT/HRCT signs was subjective, and there are no generally accepted criteria for such reading.
  • The authors described image quality as generally good but did not analyze it in relation to BMI. They suggested that the lower scores in heavier people may come from findings being overlooked in poorer-quality images.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Asbestosis.

Medical terms in this study, explained in our Lexicon: High-Resolution CT (HRCT), Fibrosis, Emphysema, Asbestos Exposure, Honeycombing.

Related studies

• The effects of secondhand smoke exposure on HRCT findings among asbestos-exposed workers — T. Vierikko, R. Järvenpää, et al. (2008)
• Increased body mass index is related to apparent circumscribed pleural thickening on plain chest radiographs — Y.C. Lee, C.K. Runnion, et al. (2001)
• Impact of body mass index on the detection of radiographic localized pleural thickening — T.C. Larson, A. Franzblau, et al. (2014)
• Chest HRCT signs predict deaths in long-term follow-up among asbestos exposed workers — T. Vehmas, P. Oksa (2014)
• Findings from high resolution computed tomography of the lung and pleura of symptom free workers exposed to amosite who had normal chest radiographs and pulmonary function tests — S. Neri, A. Antonelli, et al. (1994)
• Emphysema findings associated with heavy asbestos-exposure in high resolution computed tomography of finnish construction workers — O. Huuskonen, L. Kivisaari, et al. (2004)

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