Fig 3. A–H, Low-grade astrocytoma (grade II/IV). Top row, left to right.

A, Axial FLAIR image (TR/TE/TI, 9000/110/2500 ms) demonstrates a lesion in the left midbrain with high signal intensity and minor mass effect.

B, Axial T1-weighted postcontrast image (TR/TE, 600/14 ms; 1 excitation) demonstrates no evidence of contrast enhancement, in keeping with a low-grade astrocytoma.

C and D, Gradient-echo (TR/TE, 1000/54 ms) axial DSC MR imaging and SD25 color map suggests low permeability throughout the lesion.

E–G, Bottom row (left to right). rCBV, CBV, and CBF maps demonstrate a few foci of mildly elevated rCBV, CBV, and CBF within the glioma.

H, MTT map demonstrates some prolongation in MTT within the tumor.