In Vivo Imaging of MSCT and Micro-CT: a Comparison

Purpose: To evaluate the potential of MSCT and a novel mu CT system to assess the volume of malignant brain tumors in rats compared to histology. Materials and Methods: Fourteen rats underwent stereotactic implantation of GFP-marked F98-glioma cells. On day 10 after implantation, animals received double-dose contrast-enhanced mu CT and MSCT imaging using Iomeprol. MSCT-and mu CT-derived tumor volumes were calculated and compared to histology (fluorescence staining) as the gold standard. Results: There was good correlation between the mu CT-derived tumor volume (69 +/- 23 mm(3)) and histology (81 +/- 14 mm(3); p > 0.14). MSCT, however, showed significantly smaller tumor volumes (55 +/- 25 mm(3)) compared to histology (p < 0.01) but was able to detect the tumors in all animals. Conclusion: mu CT allows in vivo imaging of the contrast-enhancing parts of experimental gliomas with high correlation to histology. Although MSCT is less suitable for assessing exact tumor volume, this method reliably detects tumors in rats. Due to the high spatial resolution, mu CT-systems could play an important role for fusion imaging, e. g. to assess experimental brain gliomas with multimodal mu CT/PET- or mu CT/MRI-fusion images.