Automated Total-Body Perfusion Imaging with ¹⁵O-Water PET Using Basis Functions and Organ-Specific Model Selection.

Area of Science:

• Nuclear Medicine
• Radiopharmacology
• Medical Imaging Physics

Background:

• Long-axial-field-of-view PET enables simultaneous whole-body perfusion measurement using ¹⁵O-water.
• Accurate quantification of perfusion and distribution volumes is crucial for understanding physiological processes.

Purpose of the Study:

• To develop and validate an automated method for computing total-body parametric perfusion and distribution volume (V_T) images using only PET data.
• To compare the results of the automated method with established gold-standard nonlinear regression analysis.

Main Methods:

• Dynamic PET/CT scans with ¹⁵O-water bolus administration in 10 subjects.
• Automated computation of total-body parametric perfusion images using single-tissue-compartment models and cluster analysis for organ identification.
• Delay correction applied to voxel time-activity curves for model linearization.

Main Results:

• High correlation (R²=0.99) and agreement between automated parametric imaging and nonlinear regression for both perfusion and V_T.
• Slopes of 0.98 for perfusion and 1.01 for V_T indicate excellent concordance.
• Automated method demonstrated robust performance across different organs with varying blood supply.

Conclusions:

• Automated total-body parametric analysis provides accurate perfusion and V_T values comparable to nonlinear regression.
• This method offers a validated, efficient approach for whole-body physiological assessment using PET.
• The findings support the utility of automated parametric imaging for comprehensive physiological studies.