Quantification of iron-labeled cells with positive contrast in mouse brains.
OBJECTIVE
To quantify small amounts of iron-labeled cells in mouse brains with magnetic resonance imaging (MRI).


METHODS
Iron-labeled cells (from 500 to 7,500) were stereotaxically transplanted into the brain of living mice that were subsequently imaged with MRI at 4.7 T. We compared four quantitative methods: (1) T2 relaxometry, (2) T2* relaxometry, (3) the volume of the cloverleaf hypointense artifact generated on T2*-weighted images, and (4) the volume of the cloverleaf hyperintense artifact generated on positive contrast images.


RESULTS
The methods based on relaxometry, whether T2 or T2*, did not correlate with the number of injected cells. By contrast, those based on measurement of cloverleaf artifact volume, whether using negative or positive enhancement, showed a significant linear relationship for the given range of cells (R [0.92-0.95], p < 0.05).


CONCLUSIONS
T2* artifact volume imaging (negative or positive) appears promising for the quantification of magnetically labeled cells following focal injection in the brain.
Brisset
Jean-Christophe
JC
Université de Lyon, Lyon 1, Lyon, France.
Sigovan
Monica
M
Chauveau
Fabien
F
Riou
Adrien
A
Devillard
Emilie
E
Desestret
Virginie
V
Touret
Monique
M
Nataf
Serge
S
Honnorat
J
J
Canet-Soulas
Emmanuelle
E
Nighoghossian
Norbert
N
Berthezene
Yves
Y
Wiart
Marlene
M
D000818:Animals; D016477:Artifacts; D001921:Brain / Q000166:cytology* / Q000378:metabolism*; D003287:Contrast Media / Q000378:metabolism*; D005260:Female; D005290:Ferric Compounds / Q000378:metabolism; D007091:Image Processing, Computer-Assisted; D007501:Iron / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D053758:Nanoparticles / Q000737:chemistry; D013194:Staining and Labeling / Q000379:methods*
D003287:Contrast Media; D005290:Ferric Compounds; C000499:ferric oxide; D007501:Iron