FIG 3. Images obtained 35 days after the start of initial antibiotic treatment in a 45-year-old man with multiple pyogenic brain abscesses.

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) represents ¹H-MRS volume of interest.

C, Axial contrast-enhanced T1-weighted (500/30) MR image shows two ring-shaped enhanced lesions in the right basal ganglion and left frontal lobe.

D, Axial diffusion-weighted (10,000/93; b = 1000 s/mm²) image shows markedly high signal intensity in the abscess cavity and slightly iso- to hypointense surrounding edema.

E, ADC map reveals low signal intensity in the abscess cavity, representing restricted diffusion, and hyperintense areas surrounding the edema.

F and G, In vivo ¹H spectra (2000/270 and 135) from the abscess cavity show a lactate (Lac) peak (1.3 ppm) that is inverted at a TE of 135 and a lipid (Lip) peak (0.8–1.2 ppm). Note the similarity of this spectral pattern to that of a necrotic brain tumor.