title: Evaluation of lung inflammation induced by intratracheal administration of LPS in mice: comparison between MRI and histology.
abstract: OBJECTIVE
  To study the in vivo effect of intratracheal administration of lipopolysaccharide (LPS) in mice by magnetic resonance imaging (MRI) and to investigate the correlation with ex vivo histological evaluation of lung inflammation and oedema.
  
  
  METHODS
  LPS (or phosphate buffered saline) was administered intratracheally to thirty male Balb/C mice at a concentration of 0.3 mg/ml in a total volume of 100 microl. Animals were divided into fifteen LPS-treated and fifteen control mice. MR images were acquired 24 h after challenge in freely breathing animals with standard ECG-gated Gradient-Echo (GRE) sequences and, in a limited number of animals, with ECG-gated Ultrashort-echo time (UTE) sequences. After MRI, animals were sacrificed, and lungs were fixed and processed for histological analysis of the total volume of healthy lung tissue.
  
  
  RESULTS
  GRE images revealed the presence of high intensity signal in lungs of LPS-treated mice that was attributable to oedema caused by alveolar inflammation. In histological slices, regions of alterations in the normal alveolar microstructure were observed that could account for MRI findings. A good correlation was observed between the volumes of lesioned tissue measured by MRI and by histology. The volume of the lesion detected by GRE sequences was lower than the volume detected by UTE sequences.
  
  
  CONCLUSIONS
  The effect of intratracheal administration of LPS in mice was investigated by MRI and histology. A good correlation was observed between GRE-MRI and histological findings. MR images obtained with UTE sequences appear to be more sensitive to the presence of lesions than those obtained by standard GRE acquisitions.
authors.affiliation: Department of Morphological and Biomedical Sciences, University of Verona, Strada Le Grazie 8, Verona, Italy. giamaica@univr.it
authors.forename: Giamaica
authors.initials: G
authors.lastname: Conti
authors.forename: Stefano
authors.initials: S
authors.lastname: Tambalo
authors.forename: Gino
authors.initials: G
authors.lastname: Villetti
authors.forename: Silvia
authors.initials: S
authors.lastname: Catinella
authors.forename: Chiara
authors.initials: C
authors.lastname: Carnini
authors.forename: Franco
authors.initials: F
authors.lastname: Bassani
authors.forename: Nicolò
authors.initials: N
authors.lastname: Sonato
authors.forename: Andrea
authors.initials: A
authors.lastname: Sbarbati
authors.forename: Pasquina
authors.initials: P
authors.lastname: Marzola
mesh_terms: D000818:Animals; D001706:Biopsy / Q000379:methods; D008070:Lipopolysaccharides; D008168:Lung / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D011014:Pneumonia / Q000139:chemically induced* / Q000175:diagnosis*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014132:Trachea / Q000187:drug effects / Q000473:pathology
chemical_list: D008070:Lipopolysaccharides
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