Gliomas are the most common type of intracranial
tumor and have the highest rate of mortality. The aims of this study were to investigate the long-term course and biological behavior of orthotopically implanted C6
gliomas and to dynamically monitor the distribution of superparamagnetic
iron oxide (
SPIO) nanocomposite-labeled C6
glioma cells in rats using 7.0T MRI. We observed that in the MRI of the rats implanted with
SPIO-labeled cells, there were pronounced hypointense signal bands, which faded over time, but remained visible up to day 27 after implantation. We observed that the first
tumors were detected as early as 2 days after implantation, presenting as slightly hyperintense regions with indefinite boundaries in the T1-weighted images (T1WIs). On the 9th day, thick
tumor feeder vessels, ~0.2 mm in diameter, were observed and these increased rapidly over time.
Edema was observed in the labeled and unlabeled groups in the T2WIs. Both the central hypointense signal area and the peripheral cogwheel-shaped hypointense signal band in the
tumor were observed on the post-contrast T1WIs, in accordance with the
necrosis observed in the photomicrographs following
hematoxylin and
eosin (HE) staining. In conclusion, labeling
tumor cells with
SPIO and performing an MRI scan dynamically monitors the development and biological behavior of
glioma at a very early stage.