title: Comparison of human lung tissue mass measurements from ex vivo lungs and high resolution CT software analysis.
abstract: BACKGROUND
  Quantification of lung tissue via analysis of computed tomography (CT) scans is increasingly common for monitoring disease progression and for planning of therapeutic interventions. The current study evaluates the quantification of human lung tissue mass by software analysis of a CT to physical tissue mass measurements.
  
  
  METHODS
  Twenty-two ex vivo lungs were scanned by CT and analyzed by commercially available software. The lungs were then dissected into lobes and sublobar segments and weighed. Because sublobar boundaries are not visually apparent, a novel technique of defining sublobar segments in ex vivo tissue was developed. The tissue masses were then compared to measurements by the software analysis.
  
  
  RESULTS
  Both emphysematous (n = 14) and non-emphysematous (n = 8) bilateral lungs were evaluated. Masses (Mean ± SD) as measured by dissection were 651 ± 171 g for en bloc lungs, 126 ± 60 g for lobar segments, and 46 ± 23 g for sublobar segments. Masses as measured by software analysis were 598 ± 159 g for en bloc lungs, 120 ± 58 g for lobar segments, and 45 ± 23 g for sublobar segments. Correlations between measurement methods was above 0.9 for each segmentation level. The Bland-Altman analysis found limits of agreement at the lung, lobe and sublobar levels to be -13.11% to -4.22%, -13.59% to 4.24%, and -45.85% to 44.56%.
  
  
  CONCLUSIONS
  The degree of concordance between the software mass quantification to physical mass measurements provides substantial evidence that the software method represents an appropriate non-invasive means to determine lung tissue mass.
authors.affiliation: Uptake Medical®, 1173 Warner Ave, Tustin, CA 92780, USA. ehenne@uptakemedical.com
authors.forename: Erik
authors.initials: E
authors.lastname: Henne
authors.forename: Joseph C
authors.initials: JC
authors.lastname: Anderson
authors.forename: Norma
authors.initials: N
authors.lastname: Lowe
authors.forename: Steven
authors.initials: S
authors.lastname: Kesten
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000465:Algorithms; D005260:Female; D006801:Humans; D008168:Lung / Q000033:anatomy & histology* / Q000000981:diagnostic imaging* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D009929:Organ Size; D011656:Pulmonary Emphysema / Q000000981:diagnostic imaging* / Q000473:pathology*; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods; D015203:Reproducibility of Results; D012984:Software; D012986:Software Validation; D014057:Tomography, X-Ray Computed / Q000379:methods*; D055815:Young Adult