title: Ultra-short echo time (UTE) MR imaging of the lung: comparison between normal and emphysematous lungs in mutant mice.
abstract: OBJECTIVE
  To investigate the utility of ultra-short echo time (UTE) sequence as pulmonary MRI to detect non-uniform disruption of lung architecture that is typical of emphysema.
  
  
  METHODS
  MRI of the lungs was conducted with a three-dimensional UTE sequence in transgenic mice with severe emphysema and their wild-type littermates in a 3 Tesla clinical MR system. Measurements of the signal intensity (SI) and transverse relaxation time (T2*) of the lung parenchyma were performed with various echo times (TEs) ranging from 100 micros to 2 ms.
  
  
  RESULTS
  Much higher SI of the lung parenchyma was observed at an UTE of 100 micros compared with longer TEs. The emphysematous lungs had reduced SIs and T2* than the controls, in particular at end-expiratory phase. The results suggested that both SI and T2* in lung parenchyma measured with the method represent fractional volume of lung tissue.
  
  
  CONCLUSIONS
  The UTE imaging provided MR signal from the lung parenchyma. Moreover, the UTE sequence was sensitive to emphysematous changes and may provide a direct assessment of lung parenchyma. UTE imaging has the potential to assist detection of localized pathological destruction of lung tissue architecture in emphysema.
authors.affiliation: Advanced Imaging Research Center, UT Southwestern Medical Center, 2201 Inwood Rd, Dallas, Texas 75390-8542, USA. masaya.takahashi@utsouthwestern.edu
authors.forename: Masaya
authors.initials: M
authors.lastname: Takahashi
authors.forename: Osamu
authors.initials: O
authors.lastname: Togao
authors.forename: Makoto
authors.initials: M
authors.lastname: Obara
authors.forename: Marc
authors.initials: M
authors.lastname: van Cauteren
authors.forename: Yoshiharu
authors.initials: Y
authors.lastname: Ohno
authors.forename: Shigehiro
authors.initials: S
authors.lastname: Doi
authors.forename: Makoto
authors.initials: M
authors.lastname: Kuro-o
authors.forename: Craig
authors.initials: C
authors.lastname: Malloy
authors.forename: Connie C
authors.initials: CC
authors.lastname: Hsia
authors.forename: Ivan
authors.initials: I
authors.lastname: Dimitrov
mesh_terms: D000818:Animals; D016477:Artifacts; D003952:Diagnostic Imaging / Q000379:methods; D006720:Homozygote; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008168:Lung / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D051379:Mice; D009038:Motion; D009154:Mutation; D010641:Phenotype; D011656:Pulmonary Emphysema / Q000473:pathology*