Spettroscopia protonica RM di lesioni isolate del tronco encefalico

Seven patients with solitary brain stem lesions (3 brain stem gliomas, 2 capillary telangectasias, 1 neuro-Behcet, 1 acute multiple sclerosis plaque) and 15 healthy volunteers were examined with single voxel proton MR spectroscopy using short TE STEAM or long TE PRESS techniques. The pontine spectrum in the healthy subjects showed a higher choline/creatine ratio than that observed in the normal supratentorial compartment. The three patients with brain stem glioma invariably showed a moderate to severe decrease of the N-acetyl-aspartate/creatine ratio associated with presence of lactate in two patients. The reduction of the N-acetyl aspartate/creatine ratio in the patients with non-neoplastic lesions was mild or absent and it was never associated with the presence of lactate. Even if further investigations are required to confirm these preliminary findings, our study indicates that proton MR spectroscopy may be of assistance in the differential diagnosis of neoplastic and nonneoplastic solitary brain stem lesions.