Magnetic resonance spectroscopic imaging in differential diagnosis for cerebral mass lesions

ABSTRACTMAGNETIC RESONANCE SPECTROSCOPIC IMAGING INDIFFERENTIAL DIAGNOSIS FOR CEREBRAL MASS LESIONSIn the case of cerebral mass lesions, for the optimal clinical management accuratediagnosis must be done. Conventional MRI is a high resolution technique for morphologicalevaluation. However in some conditions it may be insufficient and new modalities givinginformation about histological biochemicals have been discovered.The aim of the study was to evaluate the role of MR spectroscopy in cerebral masslesions with sensitivity, specificity of neoplastic-nonneoplastic lesion differential diagnosis.In the study, for total 55 cases whose diagnosis were definite with pathological orclinical and radiological follow-up, 37 cases single and remaining 18 cases multivoxelimaging have been performed.In PRESS localization method Probe-P pulse sequence were studied with intermediateTE (TE=144). Twenty of cases were diagnosed as tumor and 35 were not. In cerebral lesionsfor tumor detection MRS was 100% sensitive and 91.7% specific. Positive predictive valuewas 86.4% and negative predictive value was 100%. In this study in the neoplastic-nonneoplastic lesion differential diagnosis NAA/Cho, NAA/Cr, Cho/Cr and Cho/NAA ratioswere evaluated and most useful was found to be Cho/NAA ratio and Cho/Cr ratio was foundto be sensitive also.It is concluded that MR Spectroscopy is a reliable imaging technique for thedifferential diagnosis in cerebral mass lesions whether it is neoplastic or nonneoplastic lesion.The spectral data?s from the study have indicated that the most sensitive parameter for tumordiagnosis is the ratio of Cho/NAA as increase in choline indicates tumor lesion.Key Words: MR Spectroscopy, brain neoplasms, diagnosis