The role of MRS in the differentiation of benign and malignant soft tissue and bone tumors

SUMMARYTHE ROLE OF MRS IN THE DIFFERENTIATION OF BENIGN AND MALIGNANTSOFT TISSUE AND BONE TUMORSIn this proton magnetic resonance spectroscopy (1H MRS) study, the value ofcholine in the discrimination of benign and malignant soft tissue and bone tumorswas investigated.The study group was consisted of thirty subjects with bone or soft tissuetumors larger than 1.5 cm in diameter. The experiments were performed in a 1.5Tesla MR scanner. Coils were selected according to specific locations. Single voxelMRS was performed for three different TE (31, 136, 272 msecs). The volume ofinterest was positioned on to the brightest enhancement. The presence of cholinpeak on at least 2 of these spectra was considered as the marker of malignancy. Thesensitivity, specifity and accuracy of the MRS in the detection of malignancydiagnosis of malignant lesions were calculated. The reproducibility of MRS andhistopathological results were tested with kappa statistics.Histopathologically, 18 (%60) of these lesions were malignant whereas 12(%40) of them were benign. With MRS, 15 (%50) of these lesions were malignantand 15 (%50) were benign. Two patients that were found to be spectroscopicallymalignant had benign histopathology. Five patients with an MRS of benign type weremalignant in histopathological examinations. MRS had a sensitivity of 72.2%, aspecificity of 83.3%, and an accuracy of 76.6% in detecting malignant bone and softtissue tumors. Interrater reliability of both techniques had a Kappa value of 0.533. Inconclusion, MRS may help in the differential diagnosis of benign and malignant softtissue and bone tumors.