title: Quantitative assessment of lung stiffness in patients with interstitial lung disease using MR elastography.
abstract: To investigate the use of magnetic resonance elastography (MRE) in the quantitative assessment of pulmonary fibrosis by comparing quantitative shear stiffness measurements of lung parenchyma in patients diagnosed with fibrotic interstitial lung disease (ILD) and healthy controls.
  
  
  
  A 1.5T spin-echo, echo planar imaging MRE (SE-EPI MRE) pulse sequence was utilized to assess absolute lung shear stiffness in 15 patients with diagnosed ILD and in 11 healthy controls. Data were collected at residual volume (RV) and total lung capacity (TLC). Spirometry data were obtained immediately prior to scanning. To test for statistical significance between RV and TLC shear stiffness estimates a two-sample t-test was performed. To assess variability within individual subject shear stiffness estimates, the intraclass correlation coefficient (ICC) and Krippendorff's alpha were calculated.
  
  
  
  Patients with ILD exhibited an average (±1 standard deviation) shear stiffness of 2.74 (±0.896) kPa at TLC and 1.32 (±0.300) kPa at RV. The corresponding values for healthy individuals were 1.33 (±0.195) kPa and 0.849 (±0.250) kPa, respectively. The difference in shear stiffness between RV and TLC was statistically significant (P < 0.001). At TLC, the ICC and alpha values were 0.909 and 0.887, respectively. At RV, the ICC and alpha values were 0.852 and 0.862, respectively.
  
  
  
  In subjects with known fibrotic interstitial lung disease, parenchymal shear stiffness is increased when compared to normal controls at both RV and TLC, with TLC demonstrating the most significant difference. MRE-derived parenchymal shear stiffness is a promising new noninvasive imaging-based biomarker of interstitial lung disease.
  
  
  
  1 Technical Efficacy: Stage 2 J. MAGN. RESON. IMAGING 2017;46:365-374.
authors.affiliation: Mayo Medical School, Mayo Clinic, Rochester, Minnesota, USA.
authors.forename: John P
authors.initials: JP
authors.lastname: Marinelli
authors.affiliation: Department of Radiology, Mayo Clinic, Rochester, Minnesota, USA.
authors.forename: David L
authors.initials: DL
authors.lastname: Levin
authors.affiliation: Department of Pulmonary and Critical Care Medicine, Mayo Clinic, Rochester, Minnesota, USA.|Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota, USA.
authors.forename: Robert
authors.initials: R
authors.lastname: Vassallo
authors.affiliation: Department of Health Sciences Research, Mayo Clinic, Rochester, Minnesota, USA.
authors.forename: Rickey E
authors.initials: RE
authors.lastname: Carter
authors.affiliation: Department of Pulmonary and Critical Care Medicine, Mayo Clinic, Rochester, Minnesota, USA.
authors.forename: Rolf D
authors.initials: RD
authors.lastname: Hubmayr
authors.affiliation: Department of Radiology, Mayo Clinic, Rochester, Minnesota, USA.|Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota, USA.
authors.forename: Richard L
authors.initials: RL
authors.lastname: Ehman
authors.affiliation: Department of Radiology, Mayo Clinic, Rochester, Minnesota, USA.
authors.forename: Kiaran P
authors.initials: KP
authors.lastname: McGee
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D017352:Echo-Planar Imaging; D054459:Elasticity Imaging Techniques; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008168:Lung / Q000000981:diagnostic imaging / Q000503:physiopathology; D017563:Lung Diseases, Interstitial / Q000000981:diagnostic imaging* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D011237:Predictive Value of Tests; D012115:Residual Volume; D033081:Shear Strength; D013147:Spirometry; D014057:Tomography, X-Ray Computed; D014109:Total Lung Capacity
keywords: MR elastography; biomarkers; interstitial lung disease; lung; pulmonary fibrosis; shear stiffness