Brain abscess - MR spectroscopy


This case shows typical brain abscess with characteristic conventional MRI and MR spectroscopy criteria. 

The main differential diagnosis of a brain abscess is cystic glioma (GBM) and cystic metastasis.

Although restricted diffusion is highly suggestive of brain abscess, cystic metastasis of squamous cell carcinoma and post-irradiation necrosis can show restricted diffusion. 

The main MRS findings in brain tumors are :

  • Decreased NAA and decreased Cr as well as decreased NAA / Cr ratio. The degree of the neuronal markers as well as the Myo-inositol reduction correlates with the high grade of the brain tumor. 
  • Increased choline (Cho).
  • Increased lipid/lactate is noted in both tumors and abscess. BUT only abscess spectrum shows amino acids, acetate, aspartate, and succinate peaks.