Figure 1.

Grades of tumor necrosis adapted from Hammoud, et al. are demonstrated on magnetic resonance (MR) images. The amount of tumor necrosis, which appears as an area of decreased signal intensity on T1-weighted images, was divided into four grades as follow: Grade 0, no necrosis apparent on the MR images; Grade I, amount of necrosis <25% of the tumor volume; Grade II, amount of necrosis 25-50% of the tumor volume; and Grade III, amount of necrosis >50% of the tumor volume