# A physiology--based parametric imaging method for FDG--PET data

## TL;DR

This paper introduces a new computational method for parametric imaging of FDG-PET data, capable of estimating kinetic parameters in complex compartmental models, validated with synthetic and real murine data.

## Contribution

It presents a novel, efficient algorithm for parametric imaging applicable to various compartmental models, including two- and three-compartment systems, with proven uniqueness and validation.

## Key findings

- The method accurately estimates kinetic parameters from FDG-PET data.
- It demonstrates robustness against noise and effective segmentation.
- Validated with synthetic and experimental murine data.

## Abstract

Parametric imaging is a compartmental approach that processes nuclear imaging data to estimate the spatial distribution of the kinetic parameters governing tracer flow. The present paper proposes a novel and efficient computational method for parametric imaging which is potentially applicable to several compartmental models of diverse complexity and which is effective in the determination of the parametric maps of all kinetic coefficients. We consider applications to [{18}F]-fluorodeoxyglucose Positron Emission Tomography (FDG-PET) data and analyze the two-compartment catenary model describing the standard FDG metabolization by an homogeneous tissue and the three-compartment non-catenary model representing the renal physiology. We show uniqueness theorems for both models. The proposed imaging method starts from the reconstructed FDG-PET images of tracer concentration and preliminarily applies image processing algorithms for noise reduction and image segmentation. The optimization procedure solves pixelwise the non-linear inverse problem of determining the kinetic parameters from dynamic concentration data through a regularized Gauss-Newton iterative algorithm. The reliability of the method is validated against synthetic data, for the two-compartment system, and experimental real data of murine models, for the renal three-compartment system.