Kinetic modeling of [{sup 99m}Tc]TRODAT-1: A novel compound for imaging the dopamine transporter
- Univ. of Pennsylvania, Philadelphia, PA (United States); and others
The purpose of this study was to characterize the in vivo binding potential and kinetic rate constants in baboons. A series of three SPECT scans were performed in each of two baboons with a mean bolus injection of 717 {+-} 78 Mbq (19.38 {+-} 2.12 mCi). Dynamic images of the brain were acquired over four hours using a triple-headed camera equipped with fan-beam collimators. Arterial and venous blood compartments were frequently sampled using a peristaltic pump throughout the duration of the study. SPECT images were reconstructed and corrected for attenuation. Regions of interest (ROIs) were placed on the corresponding MRI reference scan to which each functional image was coregistered. Arterial and venous blood samples were corrected for metabolism and converted to units of concentration in the reconstruction domain using experimentally measured calibration factors for the camera. Using analytical solutions to the three-compartment model with the Levenberg-Marquardt minimization technique, each study was individually fit to a kinetic parameter vector. Additionally within each subject the three corresponding studies were fit to a single parameter vector by constraining the binding potential, distribution volume, and dissociation rate constant to improve the identifiability of the convergent solutions. A Monte Carlo simulator provided covariance matrix estimates for parameter vectors. The results showed that [{sup 99m}Tc]TRODAT-1 localized in the basal ganglia. SPECT image analysis of the caudate yielded binding potential values of 2.16 and 2.91 in the first baboon and 3.30, 2.70, and 2.89 in the second baboon. The respective binding potential values for these subjects using the simultaneous fitting technique yielded values of 2.30 and 1.95. Similar values were obtained for the putamen.
- OSTI ID:
- 563337
- Report Number(s):
- CONF-970602-; ISSN 0161-5505; TRN: 97:004028-0009
- Journal Information:
- Journal of Nuclear Medicine, Vol. 38, Issue Suppl.5; Conference: 44. annual meeting of the Society of Nuclear Medicine, San Antonio, TX (United States), 2-5 Jun 1997; Other Information: PBD: May 1997
- Country of Publication:
- United States
- Language:
- English
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