title: Visual vs Fully Automatic Histogram-Based Assessment of Idiopathic Pulmonary Fibrosis (IPF) Progression Using Sequential Multidetector Computed Tomography (MDCT).
abstract: OBJECTIVE
  To describe changes over time in extent of idiopathic pulmonary fibrosis (IPF) at multidetector computed tomography (MDCT) assessed by semi-quantitative visual scores (VSs) and fully automatic histogram-based quantitative evaluation and to test the relationship between these two methods of quantification.
  
  
  METHODS
  Forty IPF patients (median age: 70 y, interquartile: 62-75 years; M:F, 33:7) that underwent 2 MDCT at different time points with a median interval of 13 months (interquartile: 10-17 months) were retrospectively evaluated. In-house software YACTA quantified automatically lung density histogram (10th-90th percentile in 5th percentile steps). Longitudinal changes in VSs and in the percentiles of attenuation histogram were obtained in 20 untreated patients and 20 patients treated with pirfenidone. Pearson correlation analysis was used to test the relationship between VSs and selected percentiles.
  
  
  RESULTS
  In follow-up MDCT, visual overall extent of parenchymal abnormalities (OE) increased in median by 5%/year (interquartile: 0%/y; +11%/y). Substantial difference was found between treated and untreated patients in HU changes of the 40th and of the 80th percentiles of density histogram. Correlation analysis between VSs and selected percentiles showed higher correlation between the changes (Δ) in OE and Δ 40th percentile (r=0.69; p<0.001) as compared to Δ 80th percentile (r=0.58; p<0.001); closer correlation was found between Δ ground-glass extent and Δ 40th percentile (r=0.66, p<0.001) as compared to Δ 80th percentile (r=0.47, p=0.002), while the Δ reticulations correlated better with the Δ 80th percentile (r=0.56, p<0.001) in comparison to Δ 40th percentile (r=0.43, p=0.003).
  
  
  CONCLUSIONS
  There is a relevant and fully automatically measurable difference at MDCT in VSs and in histogram analysis at one year follow-up of IPF patients, whether treated or untreated: Δ 40th percentile might reflect the change in overall extent of lung abnormalities, notably of ground-glass pattern; furthermore Δ 80th percentile might reveal the course of reticular opacities.
authors.affiliation: Department of Surgical Sciences, Section of Diagnostic Imaging at University of Parma, Parma, Italy; Translational Lung Research Centre (TLRC), Member of the German Center for Lung Research (DZL), Heidelberg, Germany; Department of Diagnostic and Interventional Radiology, University of Heidelberg, Heidelberg, Germany.
authors.forename: Davide
authors.initials: D
authors.lastname: Colombi
authors.affiliation: Translational Lung Research Centre (TLRC), Member of the German Center for Lung Research (DZL), Heidelberg, Germany; Department of Diagnostic and Interventional Radiology, University of Heidelberg, Heidelberg, Germany; Department of Clinical Radiology, University of Munich, Munich, Germany.
authors.forename: Julien
authors.initials: J
authors.lastname: Dinkel
authors.affiliation: Translational Lung Research Centre (TLRC), Member of the German Center for Lung Research (DZL), Heidelberg, Germany; Department of Diagnostic and Interventional Radiology, University of Heidelberg, Heidelberg, Germany.
authors.forename: Oliver
authors.initials: O
authors.lastname: Weinheimer
authors.affiliation: Department of Diagnostic and Interventional Radiology, University of Heidelberg, Heidelberg, Germany.
authors.forename: Berenike
authors.initials: B
authors.lastname: Obermayer
authors.affiliation: Translational Lung Research Centre (TLRC), Member of the German Center for Lung Research (DZL), Heidelberg, Germany; Department of Diagnostic and Interventional Radiology, University of Heidelberg, Heidelberg, Germany; Department of Pneumology, Iuliu Hatieganu University of Medicine and Pharmacy in Cluj-Napoca, Cluj-Napoca, Romania.
authors.forename: Teodora
authors.initials: T
authors.lastname: Buzan
authors.affiliation: Division of Medical and Biological Informatics (E130), German Cancer Research Center (DFKZ), Heidelberg, Germany.
authors.forename: Diana
authors.initials: D
authors.lastname: Nabers
authors.affiliation: Translational Lung Research Centre (TLRC), Member of the German Center for Lung Research (DZL), Heidelberg, Germany; Department of Pneumology and respiratory critical care medicine, Center for interstitial and rare lung diseases, Thoraxklinik at University of Heidelberg, Heidelberg, Germany.
authors.forename: Claudia
authors.initials: C
authors.lastname: Bauer
authors.affiliation: Translational Lung Research Centre (TLRC), Member of the German Center for Lung Research (DZL), Heidelberg, Germany; Department of Pneumology and respiratory critical care medicine, Center for interstitial and rare lung diseases, Thoraxklinik at University of Heidelberg, Heidelberg, Germany.
authors.forename: Ute
authors.initials: U
authors.lastname: Oltmanns
authors.affiliation: Translational Lung Research Centre (TLRC), Member of the German Center for Lung Research (DZL), Heidelberg, Germany; Department of Pneumology and respiratory critical care medicine, Center for interstitial and rare lung diseases, Thoraxklinik at University of Heidelberg, Heidelberg, Germany.
authors.forename: Karin
authors.initials: K
authors.lastname: Palmowski
authors.affiliation: Translational Lung Research Centre (TLRC), Member of the German Center for Lung Research (DZL), Heidelberg, Germany; Department of Pneumology and respiratory critical care medicine, Center for interstitial and rare lung diseases, Thoraxklinik at University of Heidelberg, Heidelberg, Germany.
authors.forename: Felix
authors.initials: F
authors.lastname: Herth
authors.affiliation: Translational Lung Research Centre (TLRC), Member of the German Center for Lung Research (DZL), Heidelberg, Germany; Department of Diagnostic and Interventional Radiology, University of Heidelberg, Heidelberg, Germany.
authors.forename: Hans Ulrich
authors.initials: HU
authors.lastname: Kauczor
authors.affiliation: Department of Surgical Sciences, Section of Diagnostic Imaging at University of Parma, Parma, Italy.
authors.forename: Nicola
authors.initials: N
authors.lastname: Sverzellati
authors.affiliation: Translational Lung Research Centre (TLRC), Member of the German Center for Lung Research (DZL), Heidelberg, Germany; Department of Pneumology and respiratory critical care medicine, Center for interstitial and rare lung diseases, Thoraxklinik at University of Heidelberg, Heidelberg, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Kreuter
authors.affiliation: Translational Lung Research Centre (TLRC), Member of the German Center for Lung Research (DZL), Heidelberg, Germany; Department of Diagnostic and Interventional Radiology, University of Heidelberg, Heidelberg, Germany.
authors.forename: Claus Peter
authors.initials: CP
authors.lastname: Heussel
mesh_terms: D000368:Aged; D018450:Disease Progression; D005260:Female; D006801:Humans; D054990:Idiopathic Pulmonary Fibrosis / Q000000981:diagnostic imaging* / Q000188:drug therapy; D008168:Lung / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography / Q000379:methods*; D011728:Pyridones / Q000627:therapeutic use; D012189:Retrospective Studies; D016896:Treatment Outcome
chemical_list: D011728:Pyridones; C093844:pirfenidone