title: T1 Relaxation Time in Lungs of Asymptomatic Smokers.
abstract: OBJECTIVE
  Interest in using T1 as a potential MRI biomarker of chronic obstructive pulmonary disease (COPD) has recently increased. Since tobacco smoking is the major risk factor for development of COPD, the aim for this study was to examine whether tobacco smoking, pack-years (PY), influenced T1 of the lung parenchyma in asymptomatic current smokers.
  
  
  METHODS
  Lung T1 measurements from 35 subjects, 23 never smokers and 12 current smokers were retrospectively analyzed from an institutional review board approved study. All 35 subjects underwent pulmonary function test (PFT) measurements and lung T1, with similar T1 measurement protocols. A backward linear model of T1 as a function of FEV1, FVC, weight, height, age and PY was tested.
  
  
  RESULTS
  A significant correlation between lung T1 and PY was found with a negative slope of -3.2 ms/year (95% confidence interval [CI] [-5.8, -0.6], p = 0.02), when adjusted for age and height. Lung T1 shortens with ageing among all subjects, -4.0 ms/year (95%CI [-6.3, -1.7], p = 0.001), and among the never smokers, -3.7 ms/year (95%CI [-6.0, -1.3], p = 0.003).
  
  
  CONCLUSIONS
  A correlation between lung T1 and PY when adjusted for both age and height was found, and T1 of the lung shortens with ageing. Accordingly, PY and age can be significant confounding factors when T1 is used as a biomarker in lung MRI studies that must be taken into account to detect underlying patterns of disease.
authors.affiliation: Department of Radiation Physics, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
authors.forename: Daniel F
authors.initials: DF
authors.lastname: Alamidi
authors.affiliation: Department of Medical Physics, Lund University, Translational Sciences, Malmö, Sweden.
authors.forename: Simon S I
authors.initials: SS
authors.lastname: Kindvall
authors.affiliation: Centre for Imaging Sciences and Biomedical Imaging Institute, Manchester Academic Health Sciences Centre, University of Manchester, Manchester, United Kingdom.
authors.forename: Penny L
authors.initials: PL
authors.lastname: Hubbard Cristinacce
authors.affiliation: Centre for Imaging Sciences and Biomedical Imaging Institute, Manchester Academic Health Sciences Centre, University of Manchester, Manchester, United Kingdom.
authors.forename: Deirdre M
authors.initials: DM
authors.lastname: McGrath
authors.affiliation: AstraZeneca R&D, Alderley Park, United Kingdom.
authors.forename: Simon S
authors.initials: SS
authors.lastname: Young
authors.affiliation: Centre for Imaging Sciences and Biomedical Imaging Institute, Manchester Academic Health Sciences Centre, University of Manchester, Manchester, United Kingdom.
authors.forename: Josephine H
authors.initials: JH
authors.lastname: Naish
authors.affiliation: Centre for Imaging Sciences and Biomedical Imaging Institute, Manchester Academic Health Sciences Centre, University of Manchester, Manchester, United Kingdom.
authors.forename: John C
authors.initials: JC
authors.lastname: Waterton
authors.affiliation: Department of Translational Medicine, Lund University, Malmö, Sweden.
authors.forename: Per
authors.initials: P
authors.lastname: Wollmer
authors.affiliation: Department of Translational Medicine, Lund University, Malmö, Sweden.
authors.forename: Sandra
authors.initials: S
authors.lastname: Diaz
authors.affiliation: AstraZeneca R&D, Mölndal, Sweden.
authors.forename: Marita
authors.initials: M
authors.lastname: Olsson
authors.affiliation: Medtech West, Chalmers University of Technology, Gothenburg, Sweden.|Antaros Medical, BioVenture Hub, Mölndal, Sweden.
authors.forename: Paul D
authors.initials: PD
authors.lastname: Hockings
authors.affiliation: Department of Radiation Physics, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
authors.forename: Kerstin M
authors.initials: KM
authors.lastname: Lagerstrand
authors.affiliation: Centre for Imaging Sciences and Biomedical Imaging Institute, Manchester Academic Health Sciences Centre, University of Manchester, Manchester, United Kingdom.|Bioxydyn Ltd, Manchester, United Kingdom.
authors.forename: Geoffrey J M
authors.initials: GJ
authors.lastname: Parker
authors.affiliation: Department of Medical Physics, Lund University, Translational Sciences, Malmö, Sweden.
authors.forename: Lars E
authors.initials: LE
authors.lastname: Olsson
mesh_terms: D000328:Adult; D000375:Aging / Q000502:physiology; D003710:Demography; D005260:Female; D006801:Humans; D008168:Lung / Q000473:pathology / Q000503:physiopathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D012129:Respiratory Function Tests; D012907:Smoking / Q000009:adverse effects*; D013997:Time Factors; D055815:Young Adult