title: Morphological and quantitative evaluation of emphysema in chronic obstructive pulmonary disease patients: A comparative study of MRI with CT.
abstract: To further validate the ability of ultrashort echo-time (UTE) magnetic resonance imaging (MRI) in quantifying lung density in patients diagnosed with chronic obstructive pulmonary disease (COPD) and to develop an MRI-based emphysema index (EI).
  
  
  
  Ten subjects clinically diagnosed with COPD (5M/5F, age 62.6 ± 8.5 years) and ten healthy subjects (2M/8F, age 48.9 ± 19.2 years) were imaged via UTE MRI at 3T (4 mm slices, 1.39 × 1.39 mm2pixels). Chest computed tomography (CT) images (generally 5 mm slices, ≈0.55 × 0.55 mm2pixels), acquired retrospectively, were compared to UTE MRI. CT lung densities, MR lung-signal density, and EI were quantified from both CT and UTE MR images via a quantitative automated analysis and compared to the percent predicted forced expiratory volume in 1 second (FEV1% predicted).
  
  
  
  EI quantified in controls via CT and UTE MRI was 0.23 ± 0.78% and 2.40 ± 1.50%, respectively; in COPD subjects it was 13.3 ± 14.9% (P = 0.021) and 12.0 ± 9.8% (P = 0.013), respectively. Bland-Altman determined the mean differences and 95% limits of agreement for COPD subjects and healthy controls were 0.06 (12.50 to -12.38). Strong correlation (R2= 0.79, P < 0.0001) existed between EIs quantified from both CT and UTE MRI. There was a slightly higher correlation between FEV1% predicted and the UTE MRI EI (R2= 0.65, P < 0.0001) compared to CT EI (R2= 0.49, P < 0.0001).
  
  
  
  Our results demonstrate a significant positive correlation between lung density and EI assessed with CT and MRI. Furthermore, UTE MRI exhibits its potential as a diagnostic alternative to CT for assessing the extent and the severity of emphysema, particularly for longitudinal studies. J. Magn. Reson. Imaging 2016;44:1656-1663.
authors.affiliation: Center for Pulmonary Imaging Research, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA.|Pulmonary Medicine, Cincinnati Children's Hospital, Cincinnati, Ohio, USA.
authors.forename: David J
authors.initials: DJ
authors.lastname: Roach
authors.affiliation: Centre de Résonance Magnétique des Systèmes Biologiques, Centre National de la Recherche Scientifique, Université de Bordeaux, Bordeaux, France.
authors.forename: Yannick
authors.initials: Y
authors.lastname: Crémillieux
authors.affiliation: Radiology Department Cincinnati Children's Hospital, Cincinnati, Ohio, USA.
authors.forename: Suraj D
authors.initials: SD
authors.lastname: Serai
authors.affiliation: Center for Pulmonary Imaging Research, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA.|Department of Physics, Washington University in St. Louis, St. Louis, Missouri, USA.
authors.forename: Robert P
authors.initials: RP
authors.lastname: Thomen
authors.affiliation: Philips Healthcare, Cleveland, Ohio, USA.
authors.forename: Hui
authors.initials: H
authors.lastname: Wang
authors.affiliation: Biostatistics and Epidemiology, Cincinnati Children's Hospital, Cincinnati, Ohio, USA.
authors.forename: Yuanshu
authors.initials: Y
authors.lastname: Zou
authors.affiliation: Pulmonary Medicine, Cincinnati Children's Hospital, Cincinnati, Ohio, USA.|Biostatistics and Epidemiology, Cincinnati Children's Hospital, Cincinnati, Ohio, USA.
authors.forename: Rhonda D
authors.initials: RD
authors.lastname: Szczesniak
authors.affiliation: University of Cincinnati College of Medicine, Cincinnati, Ohio, USA.
authors.forename: Sadia
authors.initials: S
authors.lastname: Benzaquen
authors.affiliation: Center for Pulmonary Imaging Research, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA.|Pulmonary Medicine, Cincinnati Children's Hospital, Cincinnati, Ohio, USA.|Radiology Department Cincinnati Children's Hospital, Cincinnati, Ohio, USA.
authors.forename: Jason C
authors.initials: JC
authors.lastname: Woods
mesh_terms: D000368:Aged; D003720:Densitometry / Q000379:methods*; D004646:Emphysema / Q000000981:diagnostic imaging / Q000473:pathology* / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D029424:Pulmonary Disease, Chronic Obstructive / Q000000981:diagnostic imaging / Q000473:pathology* / Q000503:physiopathology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*
keywords: COPD; emphysema; pulmonary imaging; ultrashort echo-time MRI