Kinetic modeling of teboroxime using dynamic SPECT imaging of a canine model.
The tomographic utility of 99mTc-labeled teboroxime has been limited because of its fast washout from the heart, which requires rapid data acquisitions that have not been feasible until the recent development of multidetector SPECT systems.


METHODS
Using a three-detector SPECT system to acquire dynamic tomographic data every 10.2 sec, we investigated the potential of modeling the kinetics of teboroxime to develop a sensitive and quantitative measure of cardiac perfusion. Seven studies were performed on four dogs; in three of the studies the LAD artery was occluded. The three-dimensional activity distributions were reconstructed and were corrected for attenuation using a transmission scan. Time-activity curves from the blood and tissue were fit to a two-compartment model with two-way exchange.


RESULTS
Performing attenuation correction during the reconstruction process affected the washin parameter k21 significantly (p < 0.0001). The washin parameter k21 also decreased significantly (p < 0.002) when the LAD was occluded.


CONCLUSIONS
The results indicate that the washin of teboroxime in myocardial tissue (k21) measured using dynamic SPECT imaging and kinetic modeling is an indicator of myocardial blood flow.
Smith
A M
AM
Department of Radiology, University of Utah, Salt Lake City 84132.
Gullberg
G T
GT
Christian
P E
PE
Datz
F L
FL
D000465:Algorithms; D000818:Animals; D003326:Coronary Circulation / Q000502:physiology*; D004285:Dogs; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging*; D007091:Image Processing, Computer-Assisted; D008297:Male; D017202:Myocardial Ischemia / Q000000981:diagnostic imaging*; D015609:Organotechnetium Compounds / Q000493:pharmacokinetics; D010091:Oximes / Q000493:pharmacokinetics; D014055:Tomography, Emission-Computed; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*
D015609:Organotechnetium Compounds; D010091:Oximes; C060156:technetium Tc 99m teboroxime