Determination of intracranial tumor volumes in a rodent brain using magnetic resonance imaging, evans blue, and histology: A comparative study

The measurement of tumor volumes is a practical and objective method of assessing the efficacy of a therapeutic agent. However, the relative accuracy of different methods of assessing tumor volume has been unclear. Using Tî weighted, gadoliniumenhanced magnetic resonance Imaging (Ti MRI), Evans Blue infusion and histology we measured intracranial tumor volumes in a rodent brain tumor model (RT2) at days 10,16 and 18 after implantation of cells in the caudate putamen. There is a good correlation between tumor volumes comparing Ti MRI and Evans Blue (r2 = 0.99), Ti MRI and Histology (r2 = 0.98) and histology and Evans Blue (r2 = 0.93). Each of these methods is reliable in estimating tumor volumes in laboratory animals. There was significant uptake of gadolinium and Evans Blue in the tumor suggesting a wide disruption of the bloodbrain barrier.