Classification of emphysema in candidates for lung volume reduction surgery: A new objective and surgically oriented model for describing CT severity and heterogeneity

Kerstin Cederlund, Ulf Tylen, Lennart Jorfeldt, Peter Aspelin

Research output: Contribution to journalArticle

26 Scopus citations


Objective: To elaborate a surgically oriented and objective model for classification of emphysema heterogeneity. Patients and interventions: CT examinations of 66 candidates for lung volume reduction surgery. Design: Emphysema severity was calculated by computer as the emphysema index (EI), a commonly used computer-based quantification that accurately assesses the extent of emphysema of a CT image. The distribution of the EI in different parts of each lung was illustrated in a diagram with the position in the lung (from cranial to caudal) on the x-axis and the EI on the y-axis. The slope of the fitted line was calculated. As a measure of the variation of the EI within each lung, the EI difference was calculated. Results: A diagram was constructed with the absolute value of slope, k, on the x-axis and EI difference on the y-axis. This resulted in a diagram differentiating markedly heterogeneous, intermediately heterogeneous, and homogeneous emphysema. Nineteen patients fulfilled the criteria of bilateral markedly heterogeneous emphysema, 3 patients filled the criteria of bilateral intermediately heterogeneous emphysema, and 18 patients filled the criteria of bilateral homogeneous emphysema. Twenty-six patients had different types of emphysema in the right and left lung. Conclusion: We present a method for classification of emphysema heterogeneity that is (1) objective, (2) surgically oriented, and (3) classifies both lungs separately.

Original languageEnglish (US)
Pages (from-to)590-596
Number of pages7
Issue number2
StatePublished - 2002
Externally publishedYes



  • CT
  • Emphysema
  • Lung volume reduction surgery

ASJC Scopus subject areas

  • Pulmonary and Respiratory Medicine

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