In vitro brain tumors: initial study using high resolution magic angle spinning ~1H MR spectroscopy

Objective To detect specimens of brain tumors with high resolution magic angle spinning 1-Hydrogen MR spectroscopy (HRMAS- 1H MRS), to analyze their soluble metabolites, and discuss its clinical value. Methods There were 30 brain tumors confirmed by pathology, including Ⅰ-Ⅱ graded astrocytomas (n=6), Ⅲ graded astrocytomas (n=7), glioblastomas (n=10), meningiomas (n=7). All data were obtained with 600 MHz spectrometer and analyzed on jMRUI software. Results ① HRMAS- 1H MRS could resolve lots of metabolites, such as NAA, PCr /Cr, GPC+PCho+Cho, Glu/Gln, Gly, Tau, Ala, Lac, mI, etc. All samples had Lac peak. 6 samples showed unknown peak at 3.72 ppm or 3.90 ppm. ② The ratio of Cho/Cr to Ⅰ-Ⅱ astrocytomas was (2.42±1.01), compared with glioblastomas (5.40±1.23), P=0.003. The ratio of Cho/Cr to Ⅲ astrocytomas was (3.48±0.59), compared with glioblastomas, P=0.01. From Ⅰ-Ⅱ astrocytomas to glioblastoma, the detected opportunities of Gly, Tau, mI and Ala were more and more. The values of Ala/Cr, Tau/Cr and Gly/Cr were elevated. The ratio of Ala/Cr to gliomas was (0.31±0.13). ③ In meningiomas, 4 cases showed no NAA, 3 cases presented NAA. The ratio of Ala/Cr was (0.53±0.28), compared with gliomas, P=0.006. Conclusion HRMAS- 1H MRS can show more detail spectrum, resolve ingredients of the Cho compound and graded degree of gliomas. With the malignancy of gliomas rising, Cho, mI, Ala, Tau and Gly may elevate. HRMAS- 1H MRS is the only method which is able of acquiring isotropic spectroscopy of solid samples.