A noninvasive [99mTc]DTPA SPECT/CT imaging methodology as a measure of lung permeability in a guinea pig model of COPD.
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.
Wu
Yanjun
Y
Molecular Imaging Center of Excellence, R&D, GlaxoSmithKline, King of Prussia, PA 19406, USA. wuyanjun2000@hotmail.com
Kotzer
Charles J
CJ
Makrogiannis
Sokratis
S
Logan
Gregory A
GA
Haley
Hyking
H
Barnette
Mary S
MS
Sarkar
Susanta K
SK
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*
D016284:Technetium Tc 99m Pentetate