FIG 4. Images obtained in a 67-year-old man with a pathologically proven right cerebellar metastasis from primary lung adenocarcinoma.

A, Axial T1-weighted image (500/30) before administration of contrast material.

B, Axial T2-weighted image (4000/100). The 2 x 2 x 2 cm voxel (box) in the center of the lesion represents the ¹H-MRS volume of interest.

C, Axial contrast-enhanced T1-weighted (500/30) MR image shows a ring-enhanced lesion in the right cerebellum.

D, Axial diffusion-weighted (10,000/93; b = 1000 s/mm²) image shows markedly low signal intensity in the necrotic part of the tumor.

E, ADC map reveals high signal intensity in the necrotic part of the tumor that is similar to that of CSF, reflecting marked diffusion.

F and G, In vivo ¹H spectra (2000/270 and 135) from the necrotic center of the tumor show a lactate (Lac) peak at 1.3 ppm that is inverted at a TE of 135.