Abstract / Description of output
Background: Total-body Positron Emission Tomography (PET), already well-established in the
pre-clinical setting, makes it possible to study multi-parameters in biological systems as a whole, rather than focusing on single tissues analysis. Simultaneous kinetic analysis of multiple organs poses some daunting new challenges. Purpose: To explore quantifying the pharmacokinetics of Na[18 F]F in multiple dissimilar murine organs simultaneously in vivo with total-body PET imaging using different compartmental models for each organ and a shared cardiovascular system. Methods: Six mice underwent a 60-min total-body PET following intravenous bolus injection of Na[18F]F. Compartmental models were constructed for each organ (heart, lungs, liver, kidneys and bone) using an image derived input function. Non-linear least squares fitting of a model that connects the five organs to a shared cardiovascular system was used to analyse both the first 3 minutes of data and the full hour. Analysis was repeated 5000 times using different initial parameter values for each duration, permitting analysis of correlations between parameters. Results: The models give a good
qualitative account of the activity curves irrespective of the duration of the data; however, the
quality of the fits to 3 minutes of data (average χν2 is 2.72) was generally better. Comparison of perfusion values to literature values was possible for the liver and lungs with the former (liver, 0.540±0.177 ml/ml/min) being well-above expectations and the latter (lungs, 0.184±0.413
ml/ml/min) in rough agreement. Correlations between microparameter values (especially affecting k2) caused very noticeable problems for data modelling from both the kidneys and the femur. Conclusions: The present study demonstrates an approach to performing kinetic modelling for multiple organs simultaneously with Na[18 F]F. The observed correlations between microparameter values remain a challenge. Nonetheless, many microparameters can be estimated reliably with a quantitative analysis of perfusion being possible for some organs.
pre-clinical setting, makes it possible to study multi-parameters in biological systems as a whole, rather than focusing on single tissues analysis. Simultaneous kinetic analysis of multiple organs poses some daunting new challenges. Purpose: To explore quantifying the pharmacokinetics of Na[18 F]F in multiple dissimilar murine organs simultaneously in vivo with total-body PET imaging using different compartmental models for each organ and a shared cardiovascular system. Methods: Six mice underwent a 60-min total-body PET following intravenous bolus injection of Na[18F]F. Compartmental models were constructed for each organ (heart, lungs, liver, kidneys and bone) using an image derived input function. Non-linear least squares fitting of a model that connects the five organs to a shared cardiovascular system was used to analyse both the first 3 minutes of data and the full hour. Analysis was repeated 5000 times using different initial parameter values for each duration, permitting analysis of correlations between parameters. Results: The models give a good
qualitative account of the activity curves irrespective of the duration of the data; however, the
quality of the fits to 3 minutes of data (average χν2 is 2.72) was generally better. Comparison of perfusion values to literature values was possible for the liver and lungs with the former (liver, 0.540±0.177 ml/ml/min) being well-above expectations and the latter (lungs, 0.184±0.413
ml/ml/min) in rough agreement. Correlations between microparameter values (especially affecting k2) caused very noticeable problems for data modelling from both the kidneys and the femur. Conclusions: The present study demonstrates an approach to performing kinetic modelling for multiple organs simultaneously with Na[18 F]F. The observed correlations between microparameter values remain a challenge. Nonetheless, many microparameters can be estimated reliably with a quantitative analysis of perfusion being possible for some organs.
| Original language | English |
|---|---|
| Journal | Medical physics |
| Publication status | Accepted/In press - 12 Oct 2024 |
Keywords / Materials (for Non-textual outputs)
- Na[18 44 F]F, total-body PET
- kinetic modelling
- calcification
- perfusion