title: A noninvasive [99mTc]DTPA SPECT/CT imaging methodology as a measure of lung permeability in a guinea pig model of COPD.
abstract: OBJECTIVE
  The purposes of this study are (1) to develop an efficient aerosol inhalation system for the delivery of [(99m)Tc]DTPA aerosol into guinea pig airways with high uniformity for measuring lung clearance using SPECT/CT imaging, as a measure of lung permeability, and (2) to use [(99m)Tc]DTPA studies in guinea pig model of chronic obstructive pulmonary disease (COPD) to determine its usefulness in studying pathogenesis of COPD.
  
  
  METHODS
  We developed an aerosol delivery system and single-photon emission computed tomography (SPECT) imaging method to measure the pulmonary clearance rate in anesthetized guinea pigs. In this system, an 830-cc rebreather exposure chamber was filled with oxygen immediately before a 5 min [(99m)Tc]DTPA (4-5 mCi/mL) aerosol exposure. The rebreather included a top mounted AeroNeb micro pump nebulizer, a nose-only exposure tube, and rear evacuation port. An 830-cc rebreather exposure chamber was filled with oxygen immediately before 5 min [(99m)Tc]DTPA (4 ∼ 5 mCi/mL) aerosol exposure. One control and one cigarette smoking group were studied.
  
  
  RESULTS
  Images showed high and uniform lung deposition and the mean clearance rate was increased by 37% in smoking group.
  
  
  CONCLUSIONS
  The combined SPECT/CT imaging method developed here can be used for serial evaluation of lung function and its response to drug therapy in guinea pig model of COPD.
authors.affiliation: Molecular Imaging Center of Excellence, R&D, GlaxoSmithKline, King of Prussia, PA 19406, USA. wuyanjun2000@hotmail.com
authors.forename: Yanjun
authors.initials: Y
authors.lastname: Wu
authors.forename: Charles J
authors.initials: CJ
authors.lastname: Kotzer
authors.forename: Sokratis
authors.initials: S
authors.lastname: Makrogiannis
authors.forename: Gregory A
authors.initials: GA
authors.lastname: Logan
authors.forename: Hyking
authors.initials: H
authors.lastname: Haley
authors.forename: Mary S
authors.initials: MS
authors.lastname: Barnette
authors.forename: Susanta K
authors.initials: SK
authors.lastname: Sarkar
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D006168:Guinea Pigs; D008168:Lung / Q000378:metabolism*; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000378:metabolism; D016284:Technetium Tc 99m Pentetate; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D016284:Technetium Tc 99m Pentetate