title: Emphysema in heavy smokers with normal chest radiography. Detection and quantification by HCRT.
abstract: OBJECTIVE
  To determine the severity and extent of emphysema in heavy smokers by high-resolution CT (HRCT) and to correlate the findings with spirometric tests (STs) and symptomatology.
  
  
  METHODS
  Fifty adult smokers with a mean age of 53 years with a smoking history of more than 30 pack years and normal chest radiographs underwent HRCT of the chest and ST (FEV1, FEV1/FVC, PEFR). Among these, 22 had symptoms of pulmonary disease and 28 were asymptomatic. Quantification of emphysema was done using a density mask program and the visual scoring method. The results were correlated with ST and symptomatology.
  
  
  RESULTS
  58% (29 out of 50) of the subjects had significant emphysema on HRCT. Eleven out of 15 with normal ST showed emphysema on HRCT while 2 with airflow obstruction on ST showed normal CT scores. 14% (4 out of 28) asymptomatic subjects had severe emphysema compared to 64% of symptomatic subjects. Emphysematous changes were predominantly seen in upper lung zones in 48% of the patients while in 52% it was distributed equally in both upper and lower zones. The number of pack years of smoking showed a positive correlation with CT scores. The correlation between HRCT scores and ST was statistically significant.
  
  
  CONCLUSIONS
  A significant number of asymptomatic and clinically undiagnosed smokers tend to have significant emphysema. HRCT helps in early detection of disease and thus helps implementation of preventive measures.
authors.affiliation: Department of Radiodiagnosis, Postgraduate Institute of Medical Education and Research, Chandigarh 160012, India.
authors.forename: K
authors.initials: K
authors.lastname: Sashidhar
authors.forename: Madhu
authors.initials: M
authors.lastname: Gulati
authors.forename: D
authors.initials: D
authors.lastname: Gupta
authors.forename: S
authors.initials: S
authors.lastname: Monga
authors.forename: S
authors.initials: S
authors.lastname: Suri
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D011656:Pulmonary Emphysema / Q000000981:diagnostic imaging* / Q000209:etiology / Q000503:physiopathology; D013902:Radiography, Thoracic; D012720:Severity of Illness Index; D012907:Smoking / Q000009:adverse effects* / Q000503:physiopathology; D013147:Spirometry; D014057:Tomography, X-Ray Computed