Hydrogen magnetic resonance spectroscopy in the diagnosis of musculoskeletal system tumors

Objective:To investigate the proton magnetic resonance spectroscopy(1H MRS) features of benign and malignant musculoskeletal system tumors in human and to explore its feasibility and application value in the differentiation diagnosis of musculoskeletal system tumors. Methods: 40 cases were included in the study in which there were 12 cases in benign tumor group and 28 cases in malignant tumor group respectively. MRI and in vivo 1H MRS were performed on all cases and in vitro 1H MRS of fresh samples were studied on 26 cases of soft tissue tumors. The 1H MRS features of all 40 cases were analyzed and the correlation study between in vivo 1H MRS findings and that of in vitro 1H MRS was performed. Cho/Cr and Lipid/Cr were calculated on workstation and a statistic test was done. We caculated the cell density of 36 tumors and performed Pearson correlation analysis between the cell density and Cho/Cr value. Results: The Cho/Cr value in the malignant tumor was larger than in the benign tumor, but the Lipid/Cr value was smaller than in the benign tumor. The differences of Cho/Cr value and Lipid/Cr value between malignant and benign soft tissue tumors were statistically significant(P0.01). In contrast to benign tumor group, in vitro 1H MRS revealed increased Cho, Lac and mI peak and decreased Lipid and Glc peak in 18 cases of the malignant tumor, as well as increased Ala, Glu, PC and Gly peak in 12 cases of the malignant tumors. In vivo 1H MRS changes of Cho and Lipid peak in the musculoskeletal system tumors was consistent with in vitro 1H MRS. The average cell density was 150/FOV in the malignant tumor group and 61/FOV in the benign tumor group respectively. The difference of the average cell density between the two groups was statistically significant. The value of the cell density had a significant positive correlation with the Cho/Cr value of tumors(r=0.882, P0.001). Conclusion: The benign and malignant musculoskeletal system tumors in human showed great difference in 1H MRS. In vivo 1H MRS findings demonstrated great consistence with that of in vitro 1H MRS. In vivo 1H MRS has high application value in the differentiation diagnosis of musculoskeletal system tumors.