Ch. Bush et al., EVALUATION OF AN ULTRASMALL SUPERPARAMAGNETIC IRON-OXIDE IN MRI IN A BONE-TUMOR MODEL IN RABBITS, Journal of magnetic resonance imaging, 7(3), 1997, pp. 579-584
Ultrasmall superparamagnetic iron oxides (USPIOs) are a class of MRI c
ontrast agents having moderately selective affinity for the reticuloen
dothelial cells of lymph nodes and bone marrow, This study evaluated a
USPIO preparation, Combidex (Code 7227), in MRI of a rabbit bone tumo
r model, VX2 carcinoma implanted into the tibial marrow of nine subjec
t rabbits was studied. After tumor growth, the subjects underwent MRI
of their lesions both before and after intravenous administration of C
ode 7227. Code 7227 was judged subjectively to conspicuously reduce th
e signal intensity of normal marrow on some pulse sequences. A hypoint
ense zone outlined the tumor margins on postcontrast imaging, which al
lowed improved visualization of the soft tissue component of the large
r lesions. Accumulation of the contrast agent in a zone of inflammatio
n outside the tumor margin was demonstrated on histologic sections of
the lesions. Code 7227 deserves additional study as a potential contra
st agent for MRI of bone tumors.