title: Ultrashort echo time MRI biomarkers of asthma.
abstract: To develop and assess ultrashort echo-time (UTE) magnetic resonance imaging (MRI) biomarkers of lung function in asthma patients.
  
  
  
  Thirty participants including 13 healthy volunteers and 17 asthmatics provided written informed consent to UTE and pulmonary function tests in addition to hyperpolarized-noble-gas 3T MRI and computed tomography (CT) for asthmatics only. The difference in MRI signal-intensity (SI) across four lung volumes (full-expiration, functional-residual-capacity [FRC], FRC+1L, and full-inspiration) was determined on a voxel-by-voxel basis to generate dynamic proton-density (DPD) maps. MRI ventilation-defect-percent (VDP), UTE SI, and DPD values as well as CT radiodensity were determined for whole lung and individual lobes.
  
  
  
  Mean SI at full-expiration (P < 0.01), FRC (P < 0.05), and DPD (P < 0.01) were greater in healthy volunteers compared to asthmatics. In asthmatics, UTE SI at full-expiration and DPD were correlated with FEV1/FVC (SI r = 0.73/P = 0.002; DPD r = 0.75/P = 0.003), RV/TLC (SI r = -0.57/P = 0.02), or RV (DPD r = -0.62/P = 0.02), CT radiodensity (SI r = 0.83/P = 0.006; DPD r = 0.71/P = 0.01), and lobar VDP (SI rs= -0.33/P = 0.02; DPD rs= -0.47/P = 0.01).
  
  
  
  In patients with asthma, UTE SI and dynamic proton-density were related to pulmonary function measurements, whole lung and lobar VDP, as well as CT radiodensity. Thus, UTE MRI biomarkers may reflect ventilation heterogeneity and/or gas-trapping in asthmatics using conventional equipment, making this approach potentially amenable for clinical use.
  
  
  
  2 J. Magn. Reson. Imaging 2017;45:1204-1215.
authors.affiliation: Robarts Research Institute, The University of Western Ontario, London, Canada.|Department of Medical Biophysics, The University of Western Ontario, London, Canada.
authors.forename: Khadija
authors.initials: K
authors.lastname: Sheikh
authors.affiliation: Robarts Research Institute, The University of Western Ontario, London, Canada.|Graduate Program in Biomedical Engineering, The University of Western Ontario, London, Canada.
authors.forename: Fumin
authors.initials: F
authors.lastname: Guo
authors.affiliation: Robarts Research Institute, The University of Western Ontario, London, Canada.|Department of Medical Biophysics, The University of Western Ontario, London, Canada.
authors.forename: Dante P I
authors.initials: DP
authors.lastname: Capaldi
authors.affiliation: Robarts Research Institute, The University of Western Ontario, London, Canada.
authors.forename: Alexei
authors.initials: A
authors.lastname: Ouriadov
authors.affiliation: Robarts Research Institute, The University of Western Ontario, London, Canada.|Department of Medical Biophysics, The University of Western Ontario, London, Canada.
authors.forename: Rachel L
authors.initials: RL
authors.lastname: Eddy
authors.affiliation: Robarts Research Institute, The University of Western Ontario, London, Canada.
authors.forename: Sarah
authors.initials: S
authors.lastname: Svenningsen
authors.affiliation: Robarts Research Institute, The University of Western Ontario, London, Canada.|Department of Medical Biophysics, The University of Western Ontario, London, Canada.|Graduate Program in Biomedical Engineering, The University of Western Ontario, London, Canada.
authors.forename: Grace
authors.initials: G
authors.lastname: Parraga
mesh_terms: D000328:Adult; D001249:Asthma / Q000503:physiopathology*; D015415:Biomarkers; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008168:Lung / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012129:Respiratory Function Tests
chemical_list: D015415:Biomarkers
keywords: 1H MRI; asthma; ultrashort echo time