On MR spectroscopy of a brain mass, the presence of elevated choline, decreased NAA, and presence of a large lipid/lactate peak with absent normal metabolites is most consistent with:
- A Brain abscess ✓
- B Low-grade glioma
- C GBM (glioblastoma)
- D Demyelinating plaque
Correct answer: A. Brain abscess
Explanation
Brain abscess on MR spectroscopy shows multiple amino acids (valine, leucine, isoleucine), succinate, acetate, and lactate peaks with complete absence of normal brain metabolites (NAA, choline, creatine) — this 'fingerprint' pattern reflects anaerobic bacterial metabolism within pus. GBM shows markedly elevated choline, reduced NAA, and a lipid-lactate peak, but retains some choline signal. Low-grade gliomas show mildly elevated choline and reduced NAA. Demyelinating plaques show elevated choline acutely with recovered NAA in remission.
Reference: Grainger & Allison's Diagnostic Radiology, 7th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.