Detection of experimentally induced brain tumors in rats using high resolution computed tomography

Objective: The feasibility of high resolution CT imaging for evaluating experimentally-induced brain tumors in rats was assessed. Methods: The gliosarcoma cell line (9 L/lacZ) was inoculated in 34 male Fischer 344 rats and CT studies were performed prior to and at 4, 7, 9, 12 and 14 days post-tumor cell implantation. Brain imaging pre- and post-contrast was performed and correlated with autopsy findings. Results: Tumors were identified by CT in 19 of the 34 animals after contrast administration and their presence was confirmed at autopsy. Tumors were present at autopsy and not identified by CT scanning in eight additional animals and in the remaining seven animals, the CT scan was normal and no tumors were present at autopsy. The sensitivity and specificity of CT scanning with contrast in detecting tumors in this rat model of gliosarcoma was 70 and 100%, respectively. Conclusion: The improved CT technology currently available can be used to identify and follow tumor burden in a rat model of gliosarcoma, and be a good tool to utilize in determining treatment outcomes experimentally, especially when MR imaging is not available.