Single voxel magnetic resonance spectroscopy in distinguishing focal neoplastic from non-neoplatic brain lesions

Abstract

Objective: Assess diagnostic utility of combined magnetic resonance imaging and magnetic resonance spectroscopy (MRI, MRS) in differentiating focal neoplastic lesions from focal non- neoplastic (infective or degenerative) brain lesions. Design: Descriptive, analytical - prospective study. Setting: The Aga Khan University MRI department. Subject: Seventy four consecutive patients. Main outcome measures: Kappa measurement of agreement was used to determine the agreement between MRI and MRI, MRS with the final diagnosis. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy of the two tests were calculated. The difference between the number of indeterminate lesions in the two tests was determined. Logistic regression demonstrated the role of confounding factors in the diagnostic use of MRS. Results: MRI, MRS had a higher agreement with the final diagnosis than MRI in isolation. The sensitivity of MRI, MRS was 4.82 times greater than that of MRI. MRI, MRS had a 1.7% increase in accuracy. MRI, MRS reduced the indeterminate MRI lesions by 5.4%. Logistic regression showed that for lesions which were enhancing, MRS yield was more helpful if the voxel position included the enhancing part. Conclusion: MRI,MRS is better than MRI alone in characterisation of neoplastic from non- neoplastic focal brain lesions.