Fig 2.

Images obtained in a 50-year-old man with surgically proven pyogenic brain abscess in the right basal ganglion.

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

B, Axial T2-weighted image (4000/100). The 2 × 2 × 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-shaped cystic lesion and surrounding edema.

D, Axial diffusion-weighted (10,000/93; b = 1000 s/mm²) image shows marked hyperintensity in the abscess cavity and slight iso- to hypointensity surrounding the edema.

E, ADC map reveals hypointensity 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 resonances representing acetate (Ac), alanine (Ala), lactate (Lac), and amino acids (AA). At a TE of 135 (G), the phase reversal resonances are well depicted at 1.5, 1.3, and 0.9 ppm, which confirms the assignment to alanine, lactate, and amino acids, respectively.