Development and Evaluation in Rat and Monkey of a Candidate Homochiral Radioligand for PET Studies of Brain Receptor Interacting Protein Kinase 1: [F]()-1-(5-(3-Fluorophenyl)-4,5-dihydro-1-pyrazol-1-yl)-2,2-dimethylpropan-1-one.

Receptor interacting protein kinase 1 (RIPK1) crucially upregulates necroptosis and is a key driver of inflammation. An effective PET radioligand for imaging brain RIPK1 would be useful for further exploring the role of this enzyme in neuroinflammation and for assisting drug discovery. Here, we report our progress on developing a PET radioligand for RIPK1 based on the phenyl-1-dihydropyrazole skeleton of a lead RIPK1 inhibitor, GSK'963.

[F]SF51, a novel F-labeled PET radioligand for translocator protein 18kDa (TSPO) in brain, works well in monkeys but fails in humans.

[F]SF51 is a novel radioligand for imaging translocator protein 18 kDa (TSPO) that previously displayed excellent imaging properties in nonhuman primates. This study assessed its performance in human brain and its dosimetry. Seven healthy participants underwent brain PET imaging to measure TSPO binding using a two-tissue compartment model (2TCM) to calculate total distribution volume ().

[C]PS13 Demonstrates Pharmacologically Selective and Substantial Binding to Cyclooxygenase-1 in the Human Brain.

Our laboratory recently developed [C]PS13 as a PET radioligand to selectively measure cyclooxygenase-1 (COX-1). The cyclooxygenase enzyme family converts arachidonic acid into prostaglandins and thromboxanes, which mediate inflammation. The total brain uptake of [C]PS13, which is composed of both specific binding and background uptake, can be accurately quantified with gold standard methods of compartmental modeling.

Increased TSPO, COX-1, and COX-2 Uptake in Bone Marrow Within a Falx Cerebri Ossification.

Ossification is uncommon, generally asymptomatic, and often incidentally identified in imaging studies. We report on a 54-year-old man who participated as a healthy volunteer in a clinical trial using PET imaging to investigate neuroinflammation. An incidental ossified lesion in the anterior falx cerebri was revealed by MRI.