18 Mar 21. Featured Paper

Kinetic modeling & parameter estimation of TSPO PET imaging in the human brain.

Link to paper on European Journal of Nuclear Medicine & Molecular Imaging

Authors

Catriona Wimberley, Sonia Lavisse, Ansel Hillmer, Rainer Hinz, Federico Turkheimer & Paolo Zanotti-Fregonara

Abstract

Purpose: Translocator protein 18-kDa (TSPO) imaging with positron emission tomography (PET) is widely used in research studies of brain diseases that have a neuro-immune component.

Quantification of TSPO PET images, however, is associated with several challenges, such as the lack of a reference region, a genetic polymorphism affecting the affinity of the ligand for TSPO, & a strong TSPO signal in the endothelium of the brain vessels.

These challenges have created an ongoing debate in the field about which type of quantification is most useful & whether there is an appropriate simplified model.

Methods: This review focuses on the quantification of TSPO radioligands in the human brain.

The various methods of quantification are summarized, including the gold standard of compartmental modeling with metabolite-corrected input function as well as various alternative models & non-invasive approaches.

Their advantages & drawbacks are critically assessed.

Results & conclusions: Researchers employing quantification methods for TSPO should understand the advantages & limitations associated with each method.

Suggestions are given to help researchers choose between these viable alternative methods.

Keywords

• Inflammation

• Kinetic modeling

• Positron emission tomography (PET)

• Translocator protein 18 kDa (TSPO)