Visualization of inflammation using 19F‐magnetic resonance imaging and perfluorocarbons

Visualisation of abscess formation with ¹⁹F magnetic resonance imaging (¹⁹F‐MRI) in a murine thigh infection model with Staphylococcus aureus. A bacterial suspension was inoculated into the left thigh muscle in mice. Two days later a perfluorocarbon (PFC) emulsion was injected intravenously and ¹⁹F/¹H‐MRI performed on day 3 after infection (24 h after injection of the PFC emulsion). (a) The T₂ map reveals an area with long T₂ times (hyperintense) indicating infected muscle tissue in the lower part of the figure. The T₂ map is presented in the pseudo color ‘hot’. (b) The corresponding ¹⁹F‐MRI shows signal accumulation (¹⁹F signal: pseudo color blue) at the outer rim of the abscess area reflecting recruitment of granulocytes and macrophages.27 (Reprinted with permission from Ref 27. Copyright 2011 University of Würzburg)

Multicolor ¹⁹F magnetic resonance imaging(¹⁹F MRI) of occlusive thrombus formation in cerebral photothrombosis (PT). PT lesion in the brain of a mouse which received two chemically shifted perfluorocarbon (PFC) compounds sequentially. PFC_A with a multi‐resonant perfluorooctlybromid was administered immediately after the end of illumination to induce PT while single‐resonant PFC_B with a peak at 90 ppm was injected with 2 h delay (a, b). Representative coronal slides of the mouse brain 3 and 8 days after induction of the PT infarction are shown (c). Administration of the first emulsion (PFC_A, blue) directly after induction of PT led to a fluorine signal throughout the cortical infarction (C2) while the second ¹⁹F marker (PFC_B, red) that was applied 2 h later accumulated only at the outer margins sparing the center of the infarcted zone (C3). Combined overlay of the ¹H turbo spin echo (TSE) data with data from both PFC compounds allowed visualization of the distinct marker distribution in a single 3D in vivo measurement (C4). The fluorine signals are due to intravascular trapping of the PFC emulsions during thrombus formation which begins in the center of the lesion as revealed by histological analysis (not shown).37 An additional ¹⁹F signal of both compounds can be observed at the site of the skin incision at the skull on the left side. (Reprinted with permission from Ref 37. Copyright 2011 University of Würzburg)

in vivo ¹⁹F magnetic resonance imaging(¹⁹F‐MRI) of neuroinflammation after lysolecithin‐induced demyelination of the left sciatic nerve.31 The rat is lying in a supine position. (a–c) show coronal (a), sagittal (b), and axial (c) ¹H MR slices through the hind quarters of a rat 5 days after nerve injury providing anatomical orientation. (d–f) represent superimposed ¹⁹F/¹H images: Note the distinct fluorine signal representing macrophage infiltration into areas of nerve injury on the left side and the absence of signal in the contralateral intact sciatic nerve.