In vivo imaging of MSCT and micro-CT: a comparison.

Purpose: To evaluate the potential of MSCT and a novel AmicroCT 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 F 98-glioma cells. On day 10 after implantation, animals received double-dose contrast-enhanced AmicroCT and MSCT imaging using Iomeprol. MSCT- and AmicroCT-derived tumor volumes were calculated and compared to histology (fluorescence staining) as the gold standard.
Results: There was good correlation between the AmicroCT-derived tumor volume (69 A+ or - 23 mm(3)) and histology (81 A + or - 14 mm(3); p > 0.14). MSCT, however, showed significantly smaller tumor volumes (55 A + or - 25 mm(3)) compared to histology (p < 0.01) but was able to detect the tumors in all animals.
Conclusion: AmicroCT 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, AmicroCT-systems could play an important role for fusion imaging, e. g. to assess experimental brain gliomas with multimodal AmicroCT/PET- or AmicroCT/MRI-fusion images.
(A A Georg Thieme Verlag KG Stuttgart A New York.)