Prospective evaluation of in vivo proton MR spectroscopy in differentiation of similar appearing intracranial cystic lesions

Proton MR spectroscopy (PMRS) has been found to be useful in differentiatin g various cystic intracranial lesions. The purpose of the present study was to prospectively evaluate the spectral pattern of various cystic lesions o f brain with similar imaging appearances and to determine the accuracy of t his technique in the differential diagnosis of these lesions. Fifty-one pat ients with intracranial cystic lesions (21 abscesses, 20 gliomas, 3 hydatid cysts, 3 arachnoid cysts, 1 case each of glioependymal cyst, xanthogranulo ma, infarction and acoustic neuroma) were evaluated with conventional MR im aging and in vivo PMRS. Ex vivo PMRS of the cystic contents aspirated at su rgery in 31 cases was also done to confirm the in-vivo results. Preoperativ e diagnosis of the lesions was based on the results of in vive PMRS. In viv o PMRS accurately predicted the pathology in 92% of the cases. We conclude that in-vivo PMRS complements imaging in better characterization of cystic intracranial mass lesions. (C) 2001 Elsevier Science Inc. All rights reserv ed.