Imaging of Orthotopic Glioblastoma Xenografts in Mice Using a Clinical CT Scanner: Comparison with Micro-CT and Histology.

ABSTRACT:

Purpose

There is an increasing need for small animal in vivo imaging in murine orthotopic glioma models. Because dedicated small animal scanners are not available ubiquitously, the applicability of a clinical CT scanner for visualization and measurement of intracerebrally growing glioma xenografts in living mice was validated.

Materials and methods

2.5x106 U87MG cells were orthotopically implanted in NOD/SCID/?c-/- mice (n = 9). Mice underwent contrast-enhanced (300 ?l Iomeprol i.v.) imaging using a micro-CT (80 kV, 75 ?As, 360° rotation, 1,000 projections, scan time 33 s, resolution 40 x 40 x 53 ?m) and a clinical CT scanner (4-row multislice detector; 120 kV, 150 mAs, slice thickness 0.5 mm, feed rotation 0.5 mm, resolution 98 x 98 x 500 ?m). Mice were sacrificed and the brain was worked up histologically. In all modalities tumor volume was measured by two independent readers. Contrast-to-noise ratio (CNR) and Signal-to-noise ratio (SNR) were measured from reconstructed CT-scans (0.5 mm slice thickness; n = 18).

Results

Tumor volumes (mean±SD mm3) were similar between both CT-modalities (micro-CT: 19.8±19.0, clinical CT: 19.8±18.8; Wilcoxon signed-rank test p = 0.813). Moreover, between reader analyses for each modality showed excellent agreement as demonstrated by correlation analysis (Spearman-Rho >0.9; p<0.01 for all correlations). Histologically measured tumor volumes (11.0±11.2) were significantly smaller due to shrinkage artifacts (p<0.05). CNR and SNR were 2.1±1.0 and 1.1±0.04 for micro-CT and 23.1±24.0 and 1.9±0.7 for the clinical CTscanner, respectively.

Conclusion

Clinical CT scanners may reliably be used for in vivo imaging and volumetric analysis of brain tumor growth in mice.

SUBMITTER: Kirschner S 

PROVIDER: S-EPMC5102379 | biostudies-literature | 2016

REPOSITORIES: biostudies-literature