Fig. 4.

MR images from a Boston Terrier with a grade III oliogdendroglioma. Two infusion procedures (CED 1,2) achieved 28% and 62% Vd, respectively, within the tumor, resulting in an 88% total reduction in tumor volume 5 months following initial treatment. Decreased tumor volume, decreased mass effect, and presumed necrosis (n) of the tumor is seen on posttreatment MR images. Real-time imaging of the first CED procedure identified poor coverage of the medial aspect of the mass (arrow head). An infusion cannula was specifically targeted to this area in the second procedure resulting in good medial coverage (arrows). Suboptimal placement of this cannula superficially within the tumor eventually resulted in leakage into the internal capsule (double arrow heads). Real-time imaging allowed detection and termination of the infusion to limit potential toxicity. Tr, transverse plane image; Sag, sagittal plane image; Dor, dorsal plane image.