Here we investigated whether magnetic resonance imaging (MRI) combined with a quantum-sensed molecule, parahydrogen-polarised [1-13C] pyruvate, could detect persistent brain metabolic alterations in a murine pseudo-infection model induced by polyinosinic–polycytidylic acid (Poly(I: C)), a Toll-like receptor 3 ligand. This evidence concerns the gene TLR3 and infection.