The Absolute Quantification Of Metabolite Concentrations In Supretentorial Gliomas With Mulit-voxel Proton Magnetic Resonance Spectroscopy

Part IFusion of MR Spectroscopic image with neuronavigation for precise guide stereotactic biopsyObjective:To achieve stereotactic biopsy based on the accurate puncture target position of magnetic resonance spectroscopic metabolic information by fuse magnetic resonance spectroscopic image and the routine three dimension neuronavigation magnetic resonance sequence.Methods:Matlab software and the Statistical Parametric Mapping (SPM) Kit program medical image fusion software Biopsy_NAV on the Apple Mac OS X image post-processing work platform. Extract and fuse spectral raw data and conventional navigation sequence information on the voxel spatial position coordinates by image fusion software Biopsy_NAV. Highlighted module mark puncture targets consistent with the size of the magnetic resonance spectroscopy voxel volume. Import the Stealth Station TRIA i7neural navigation system to identify.Results:Spectroscopic data and navigation data are generated and integrated in the same coordinate system. The precise fusion medical image, which spatial positioning is coincide, can be identified by neuronavigation system.Conclusion:The structural-metabolic MRSI navigation image which containing the marked targets highlighted module can precise guide puncture targets. The correlation between absolute metabolite concentrations of2D-1H-MRS and histopathology based on stereotactic biopsies-clinical value for margin delineation of supretentorial gliomasObjective:To evaluate the relationship between absolute metabolite concentrations of tCho, tNAA and tCr acquired from2D-1H-MRS and the histiopathological features in the same biopsy sites, so an optimal value of absolute concentration of metabolite distinguishing tumor from nontumor was calculated which can be used to define the extent of gliomas.Methods:Specimens from tumor core and peritumoral region of glioma were obtained by frameless stereotactic biopsy with the aid of the structural-metabolic MRSI navigation image. The absolute metabolite concentrations of tCho, tNAA, tCr using the tissue water as internal reference was calculated through a commercial software Linear combination model (LCModel), that normalized to spectral date obtained from a reference basis set of known metabolite concentrations after input of the raw data from biopsy targets. Hematoxylin and eosin (H&E) and immunohistochemical staining with p53、CD34、MIB-1、IDH-1、GFAP antibodies were performed in all samples. The correlation of those multiparamets from biopsy sites with the histopathologic finding (cell density, microvessel density, and MIB-1labelling index) are examined by the Pearson correlation analysis and Logstic multiparameter regression analysis.Results:The absolute metabolite concentrations of tCho showed a strong positive correlate with cell density, microvessel density, and MIB-1labelling index (P<0.05). The absolute metabolite concentrations of tNAA showed a strong negative correlate with cell density, microvessel density, and MIB-1labelling index (P<0.05). All specimens using Logstic multiparamets regression analysis, which found that the probability of the voxel being a tumor became19.666times if the absolute metabolite concentrations of tCho increased one unit, the probability of the voxel being a tumor decreased53%if the absolute metabolite concentrations of tNAA reduced one unit. The absolute metabolite concentrations of tCr did not influenced the pathological results. Further, Multivariant Logistic regression function with samples of low grade astrocyoma and gliosis, normal brain tissue, which found that the the probability of the voxel being a tumor decreased52.3%if the absolute metabolite concentrations of tNAA reduced one unit. The absolute metabolite concentrations of tCho and tCr did not influenced the pathological results.Conclusions:The absolute metabolite concentrations of tCho, tNAA significantly correlated with the histiopathological features. The probability of the voxel infiltrated by glioma can be calculated by absolute quantification of metabolites, especially based on the concentrations of tNAA, can be applied in glioma surgery for detecting the glioma infiltrated extent. Absolute metabolite concentrations of2D-1H-MRS in the grading supretentorial gliomas and assessment of superior parametersObjective:To investigate the absolute metabolite concentration changes in tumoral and peritumoral regions of various grades of gliomas for the assessment the usefulness of2D-1H-MRS in grading supretentorial gliomas and superior parameters for diagnostic accuracy.Methods:2D-1H-MRS examination was preoperatively performed in42patients with pathologically proved gliomas:12low-grade gliomas (WHO Ⅱ);30high-grade gliomas included13anaplastic gliomas (WHO Ⅲ) and17gliomas multiform (WHOⅣ).The sub-group of12low-grade gliomas included9astrocytomas,2oligdendroastrocytomas, and1oligdendroglioma. The sub-group13anaplastic gliomas included9anaplastic astrocytomas, and4anaplastic oligdendrogliomas. Raw data of spectra were processed on a commercial software Linear combination model (LCModel) normalized to spectral date obtained from a reference basis set of known metabolite concentrations. The absolute metabolite concentrations of tCho, tCr, and NAA were measured from the tumor parenchyma, peritumoral region, and contralateral normal brain regions. The differences in absolute metabolite concentrations of these three parameters between tumor parenchyma, peritumoral region, and contralateral normal brain regions in same grade of astrocytomas were compared separately. The differences in absolute metabolite concentrations of these three parameters between various grades of astrocytomas in tumor parenchyma, peritumoral region, and contralateral normal brain regions were compared separately. Cutoff values of these three parameters in the tumoral and peritumoral region for distinguishing low-grade gliomas from high-grade gliomas were determined by receiver operating characteristic (ROC) analysis.Results:The absolute metabolite concentration of tCho at tumoral region and the absolute metabolite concentration of tNAA at peritumoral region were statistically different between the glioblastoma and WHO grade Ⅲ and WHO grade Ⅱ astrocytomas respectively (P<0.05). If an optimal threshold value of peritumoral tNAA set absolute concentration for6.63 mmol/L, the diagnostic specificity was96.7%. The tNAA absolute metabolite concentration of glioblastoma, WHO gradeⅢ astrocytoma, WHO grade Ⅱ astrocytoma was gradually increased from tumoral core, peritumoral region to contralateral white matter (P<0.05). The tCho absolute metabolite concentration of glioblastoma, WHO gradeⅢ astrocytoma, WHO grade Ⅱ astrocytoma was gradually decreased from tumoral core, peritumoral region to contralateral white matter (P<0.05). The absolute metabolite concentration of tCr and tNAA at tumoral region were statistically different between anaplastic astrocytomas and anaplastic oligdendrogliomas (P<0.05).Conclusion:The absolute metabolite concentration of tumoral tNAA and peritumoral tCho was very useful for identifying glioblastoma, WHO grade astrocytoma Ⅲ tumor, astrocytoma WHO grade Ⅱ. The absolute metabolite concentration of peritumoral tNAA for high and low-grade astrocytomas tumor grading has higher specificity. The absolute metabolite concentration of tNAA was very useful for determine the degree of infiltration of low-grade gliomas. The absolute metabolite concentration of tCr, tNAA contribute to the identification of the WHO grade Ⅲ oligodendroglioma and astrocytoma.