title: Disease progression in usual interstitial pneumonia compared with desquamative interstitial pneumonia. Assessment with serial CT.
abstract: OBJECTIVE
  To determine the outcome of areas of ground-glass attenuation and assess disease progression on serial high-resolution CT (HRCT) scans of patients with biopsy specimen-proved usual interstitial pneumonia (UIP) and desquamative interstitial pneumonia (DIP).
  
  
  METHODS
  Twelve patients with biopsy specimen-proved UIP and 11 patients with biopsy specimen-proved DIP who had initial and follow-up HRCT scans (median interval, 10 months) were reviewed. Eleven patients with UIP and 11 with DIP received treatment between the initial and follow-up CT scans. The scans were evaluated for the presence and extent of ground-glass attenuation, irregular linear opacities and honeycombing, and overall extent of parenchymal involvement.
  
  
  RESULTS
  On initial CT scans, all 12 patients with UIP had areas of ground-glass attenuation (mean +/- SD extent, 30 +/- 16%) and irregular lines (mean +/- SD extent, 17 +/- 7%) and 10 patients had honeycombing (mean +/- SD extent, 10 +/- 6%). All 11 patients with DIP had areas of ground-glass attenuation on initial HRCT scans (mean +/- SD extent, 51 +/- 26%), 5 patients had irregular linear opacities (mean +/- SD extent, 5 +/- 5%), and 1 patient had honeycombing. Nine of the 12 patients with UIP showed increase in the extent of ground-glass attenuation (n = 6) or progression to irregular lines (n = 2) or honeycombing (n = 4) on follow-up as compared with only 2 patients with DIP who showed progression to irregular lines (n = 1) or honeycombing (n = 1) (p < 0.01 chi 2 test).
  
  
  CONCLUSIONS
  In patients with UIP, areas of ground-glass attenuation usually increase in extent or progress to fibrosis despite treatment. Areas of ground-glass attenuation in most patients with DIP remain stable or improve with treatment.
authors.affiliation: Department of Diagnostic Radiology, Mayo Clinic, Rochester, MN 55905, USA.
authors.forename: T E
authors.initials: TE
authors.lastname: Hartman
authors.forename: S L
authors.initials: SL
authors.lastname: Primack
authors.forename: E Y
authors.initials: EY
authors.lastname: Kang
authors.forename: S J
authors.initials: SJ
authors.lastname: Swensen
authors.forename: D M
authors.initials: DM
authors.lastname: Hansell
authors.forename: G
authors.initials: G
authors.lastname: McGuinness
authors.forename: N L
authors.initials: NL
authors.lastname: Müller
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging*; D017563:Lung Diseases, Interstitial / Q000000981:diagnostic imaging* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D014057:Tomography, X-Ray Computed