title: Echo time dependence of observed T1 in the human lung.
abstract: BACKGROUND
  This work is intended to demonstrate that T1 measured in the lungs depends on the echo time (TE) used. Measuring lung T1 can be used to gain quantitative morphological and functional information. It is also shown that this dependence is particularly visible when using an ultra-short TE (UTE) sequence with TE well below 1 ms for T1 quantification in lung tissue, rather than techniques with TE on the order of 1-2 ms.
  
  
  METHODS
  The lungs of 12 healthy volunteers (aged 22 to 33 years) were examined at 1.5 Tesla. A segmented inversion recovery Look-Locker multi-echo sequence based on two-dimensional UTE was used for independent T1 quantification at five TEs between TE1  = 70 μs and TE5  = 2.3 ms.
  
  
  RESULTS
  The measured T1 was found to increase gradually with TE from 1060 ± 40 ms at TE1 to 1389 ± 53 ms at TE5 (P < 0.001).
  
  
  CONCLUSIONS
  Measuring T1 at ultra-short echo times reveals a significant dependence of observed T1 on the echo time. Thus, any comparison of T1 values should also consider the TEs used. However, this dependence on TE could also be exploited to gain additional diagnostic information on the tissue compartments in the lung.
authors.affiliation: Research Centre Magnetic Resonance Bavaria e.V.(MRB), Würzburg, Germany.|Translational Lung Research Centre, member of the German Centre for Lung Research (DZL), Gieβen, Germany.|Department of Diagnostic and Interventional Radiology, University of Heidelberg, Heidelberg, Germany.
authors.forename: Simon M F
authors.initials: SM
authors.lastname: Triphan
authors.affiliation: Translational Lung Research Centre, member of the German Centre for Lung Research (DZL), Gieβen, Germany.|Department of Diagnostic and Interventional Radiology, University of Heidelberg, Heidelberg, Germany.
authors.forename: Bertram J
authors.initials: BJ
authors.lastname: Jobst
authors.affiliation: Research Centre Magnetic Resonance Bavaria e.V.(MRB), Würzburg, Germany.
authors.forename: Felix A
authors.initials: FA
authors.lastname: Breuer
authors.affiliation: Translational Lung Research Centre, member of the German Centre for Lung Research (DZL), Gieβen, Germany.|Department of Diagnostic and Interventional Radiology, University of Heidelberg, Heidelberg, Germany.
authors.forename: Mark O
authors.initials: MO
authors.lastname: Wielpütz
authors.affiliation: Translational Lung Research Centre, member of the German Centre for Lung Research (DZL), Gieβen, Germany.|Department of Diagnostic and Interventional Radiology, University of Heidelberg, Heidelberg, Germany.
authors.forename: Hans-Ulrich
authors.initials: HU
authors.lastname: Kauczor
authors.affiliation: Translational Lung Research Centre, member of the German Centre for Lung Research (DZL), Gieβen, Germany.|Department of Diagnostic and Interventional Radiology, University of Heidelberg, Heidelberg, Germany.|Radiologie Darmstadt, Darmstadt, Germany.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Biederer
authors.affiliation: Research Centre Magnetic Resonance Bavaria e.V.(MRB), Würzburg, Germany.|Department of Experimental Physics 5, University of Würzburg, Würzburg, Germany.
authors.forename: Peter M
authors.initials: PM
authors.lastname: Jakob
mesh_terms: D000328:Adult; D003287:Contrast Media / Q000737:chemistry; D064368:Healthy Volunteers; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008168:Lung / Q000473:pathology* / Q000502:physiology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D015233:Models, Statistical; D019047:Phantoms, Imaging; D059629:Signal-To-Noise Ratio; D013997:Time Factors; D055815:Young Adult
chemical_list: D003287:Contrast Media
keywords: T1 mapping; lung imaging; pulmonary; two compartment