Non-specific binding of [18F]FDG to calcifications in atherosclerotic plaques: experimental study of mouse and human arteries.
OBJECTIVE
[(18)F]FDG has been used as an inflammation marker and shown to accumulate in inflammatory atherosclerotic plaques. The aim of this study was to investigate the uptake and location of [(18)F]FDG in atherosclerotic plaque compartments.


METHODS
The biodistribution of intravenously administered [(18)F]FDG was analysed in atherosclerotic LDLR/ApoB48 mice (n=11) and control mice (n=9). Digital autoradiography was used to detect the ex vivo distribution in frozen aortic sections. In vitro binding of [(18)F]FDG in human atherosclerotic arteries was also examined.


RESULTS
The uptake of [(18)F]FDG was significantly higher in the aorta of atherosclerotic mice as compared with the control mice. Autoradiography of excised arteries showed higher [(18)F]FDG uptake in the plaques than in the healthy vessel wall (mean ratio +/-SD 2.7+/-1.1). The uptake of [(18)F]FDG in the necrotic, calcified sites of the advanced atherosclerotic lesions was 6.2+/-3.2 times higher than that in the healthy vessel wall. The in vitro studies of human arterial sections showed marked binding of [(18)F]FDG to the calcifications but not to other structures of the artery wall.


CONCLUSIONS
In agreement with previous studies, we observed [(18)F]FDG uptake in atherosclerotic plaques. However, prominent non-specific binding to calcified structures was found. This finding warrants further studies to clarify the significance of this non-specific binding in human plaques in vivo.
Laitinen
Iina
I
Turku PET Centre, University of Turku, Turku, Finland. iina.laitinen@tyks.fi
Marjamäki
Päivi
P
Haaparanta
Merja
M
Savisto
Nina
N
Laine
V Jukka O
VJ
Soini
Sanna L
SL
Wilson
Ian
I
Leppänen
Pia
P
Ylä-Herttuala
Seppo
S
Roivainen
Anne
A
Knuuti
Juhani
J
D000818:Animals; D001011:Aorta / Q000378:metabolism / Q000473:pathology; D053283:Apolipoprotein B-48 / Q000172:deficiency; D001158:Arteries / Q000378:metabolism* / Q000473:pathology*; D050197:Atherosclerosis / Q000150:complications / Q000378:metabolism* / Q000473:pathology; D001345:Autoradiography; D002114:Calcinosis / Q000150:complications / Q000378:metabolism*; D016893:Carotid Stenosis / Q000150:complications / Q000378:metabolism* / Q000473:pathology; D005263:Femoral Artery / Q000378:metabolism / Q000473:pathology; D019788:Fluorodeoxyglucose F18 / Q000378:metabolism* / Q000493:pharmacokinetics; D006801:Humans; D007249:Inflammation / Q000150:complications / Q000378:metabolism / Q000473:pathology; D051379:Mice; D018345:Mice, Knockout; D011973:Receptors, LDL / Q000172:deficiency; D014018:Tissue Distribution
D053283:Apolipoprotein B-48; D011973:Receptors, LDL; D019788:Fluorodeoxyglucose F18