In vivo monitoring of inflammation after cardiac and cerebral ischemia by fluorine magnetic resonance imaging.
BACKGROUND
In this study, we developed and validated a new approach for in vivo visualization of inflammatory processes by magnetic resonance imaging using biochemically inert nanoemulsions of perfluorocarbons (PFCs).


RESULTS
Local inflammation was provoked in 2 separate murine models of acute cardiac and cerebral ischemia, followed by intravenous injection of PFCs. Simultaneous acquisition of morphologically matching proton ((1)H) and fluorine ((19)F) images enabled an exact anatomic localization of PFCs after application. Repetitive (1)H/(19)F magnetic resonance imaging at 9.4 T revealed a time-dependent infiltration of injected PFCs into the border zone of infarcted areas in both injury models, and histology demonstrated a colocalization of PFCs with cells of the monocyte/macrophage system. We regularly found the accumulation of PFCs in lymph nodes. Using rhodamine-labeled PFCs, we identified circulating monocytes/macrophages as the main cell fraction taking up injected nanoparticles.


CONCLUSIONS
PFCs can serve as a "positive" contrast agent for the detection of inflammation by magnetic resonance imaging, permitting a spatial resolution close to the anatomic (1)H image and an excellent degree of specificity resulting from the lack of any (19)F background. Because PFCs are nontoxic, this approach may have a broad application in the imaging and diagnosis of numerous inflammatory disease states.
Flögel
Ulrich
U
Institut für Herz- und Kreislaufphysiologie, Heinrich-Heine-Universität, Postfach 101007, 40001 Düsseldorf, Germany. floegel@uni-duesseldorf.de
Ding
Zhaoping
Z
Hardung
Hendrik
H
Jander
Sebastian
S
Reichmann
Gaby
G
Jacoby
Christoph
C
Schubert
Rolf
R
Schrader
Jürgen
J
D000818:Animals; D002545:Brain Ischemia / Q000473:pathology*; D004655:Emulsions; D005466:Fluorocarbons; D007249:Inflammation / Q000175:diagnosis* / Q000209:etiology; D008198:Lymph Nodes; D008264:Macrophages; D008279:Magnetic Resonance Imaging / Q000379:methods*; D051379:Mice; D009000:Monocytes; D017202:Myocardial Ischemia / Q000473:pathology*
D004655:Emulsions; D005466:Fluorocarbons