Study On The Correlation Between The Value Of Apparent Diffusion Coefficient And MR Spectroscopy And Proliferation Activity Of Brain Gliomas

Glioma belonging to the neutral epithelial tumors is the most common tumors of the central nervous system. It is accounting for about40%-60%of the total primary intracranial tumors. Glioma’s development occurs as the result of multiple genes and various factors. Cerebral gliomas with their high proliferation resistance, recurrence, and characteristics such as high rate of disability and death, are difficult in clinical treatment. The prognosis of cerebral glioma is also poor. It is essential for gliomas, in particular proliferative activity, to make an accurate assessment and judgment in glioma patients before treatment. Biopsies are now considered as the main method of determining the tumor type, proliferative activity and other biological traits. For the biopsy is invasive and exists the risk of complications, and the differentiation of glioma is heterogeneous, there is not complete reaction of tumor cell proliferation status of real chance. Access to a non-invasive, accurate prediction method for diagnosis of glioma cell proliferation, diagnosis therapy and prognosis in patients with cerebral glioma is of great significance. With the rapid development of the technology of magnetic resonance imaging, it become possible for the clinician to understand the glioma cell proliferative activity by non-invasive magnetic resonance diffusion weighted imaging (DWI) and multi voxel proton magnetic resonance spectroscopic imaging (1H-MRS).Magnetic resonance imaging (MRI) technology has become the preferred imaging method for evaluation of gliomas, for it can improve the preoperative localization and qualitative diagnosis of glioma ability. Conventional MRI examination in diagnosis of intracranial lesions tends to be based on typical parts, forms of the disease, peripheral edema, strengthen the comprehensive analysis to make conclusions. But different lesions may have a similar routine MRI manifestation, often leading to mistake judgments of tumor proliferation and good evil, still has limitations. New type of the clinical application of magnetic resonance imaging technology(such as PWI, DWI, DTI, fMRI, MRS etc.), largely overcome the deficiency of the previous. These techniques can provide tumor’s blood dynamics, metabolism and functional areas of the cortex and other functional informations.,which are important for the differential diagnosis of glioma, judgment, determining operation boundaries, prognosis, and monitoring treatment efficacy and clearly. MR diffusion weighted imaging (DWI) is a new field compared with the traditional MRI. DWI first used in biology and in vivo non-invasive measurement and description of diffusion coefficient, in order to study the molecular motion and understand the normal and disease state of interstitial water exchange. By measuring the motion of water molecule, we can get the informations of medium and barrier. Proton magnetic resonance spectroscopic imaging (1H-MRS) can study the pathophysiology change of human by detecting brain tissue within the various metabolites on human. By1H-MRS, neural biochemical information of local organizations can diagnosis of glioma and malignant classification, tumor biopsy target formulation, radiation necrosis and recurrence of the tumor identification provides important biochemical informations in living. MRS can also provide abnormal metabolic information in the surrounding anatomic normal regions during the growth of tumor invasion.Previous clinical specific knowledge on glioma only comes from intraoperatively removed tumor pathologic examination. The information provided by traditional pathology which is mainly based on morphology could not satisfy the need of patients and clinicians. The clinicians hope to obtain reliable informations on tumor biological behavior, so that they can design the individualized plan of effective and reliable treatment. Patients and their families wish to understand the malignant degree of cancer, survival and prognosis, and so on. The importance of tumor Molecular Pathology comes even more to the fore. By individual tumor cells of immunohistochemical markers, chromosomal markers, genetic marker, Molecular Pathology learn in protein or gene level Shang on tumor cell of cancer gene, anti cancer gene, growth factor, receptor, and other changes were detected, based on the above changes to judge a purpose tumor cell’s biological behavior, and made judge on its prognosis, design best treatment. Ki-67is a kind of proliferating cell nuclear antigen, it is more positive nuclear proliferation marker gene at present. The expression change of Ki-67can more objectively reflect the tumor proliferative activity, Ki-67high proliferation index indicated cell proliferation was active, high malignancy, poor prognosis; low index indicated malignant degree is low, prognosis is good.Study of different grade gliomas ADC value,1H-MRS metabolite ratio changes and the expression of Ki-67, and analysis of the correlation between them. Through analysis of magnetic resonance spectroscopy and diffusion-weighted Imaging can enhance awareness of tumor proliferation activity, increase the accuracy level of pathological diagnostic before treatment, help developing clinical treatment plan and providing greater assessment of prognosis in patients. This topic concerns main metabolites (NAA, Cr, Cho) and ADC value in consolidation and (or) strengthening part of glioma, studies the metabolite ratio (NAA/Cr, Cho/Cr and NAA/Cho)and ADC value of different grade gliomas (normal group on the other side of the same parts, low level group of Ⅰ/Ⅱ and the high level group of Ⅲ/Ⅳ). The Ki-67proliferation changes in different degree of malignant glioma tumor cell in40patients with brain tumor tissue specimens and the relationships between them are analysised in immunohistochemical method (low+high level group level group) The expression and function of ADC value, respectively1H-MRS metabolite ratios and Ki-67in different grade gliomas (normal brain tissue, low level group of Ⅰ/Ⅱ and the high level group of Ⅲ/Ⅳ) are studied in statistical method, as well as the correlation between former two and the latter. The role and relevance of DWI,’H-MRS, Ki-67in the classification process of tumor are discuussed.PurposeThe relevance and values of DWI and multi-voxel1H-MRS with Ki-67expression in different grade of glioma on the topic are discussed. It is expected that DWI, multi-voxel1H-MRS and other imaging techniques become the biological imaging index and powerful theoretical and experimental basis on clear the proliferation activity of glioma cell, realization of in vivo, non-invasive evaluation of cerebral glioma biological behavior.Methods40cases of cerebral glioma collected in our hospital from December2009to September2011, with routine MRI, DWI and multi-voxel1H-MRS examination, postoperative pathological examination, are designed for low grade gliomas Group (Ⅰ～Ⅱ grade) and the high grade group of glioma (Ⅲ～Ⅳ grade) in20patients each according to the WHO2000classification of glioma tumor-standard. This topic concerns main metabolites (NAA, Cr, Cho) and ADC value in consolidation and (or) strengthening part of glioma, studies the metabolite ratio (NAA/Cr, Cho/Cr and NAA/Cho)and ADC value of different grade gliomas (normal group on the other side of the same parts, low level group of Ⅰ/Ⅱ and the high level group of Ⅲ/Ⅳ). The Ki-67proliferation changes in different degree of malignant glioma tumor cell in40patients with brain tumor tissue specimens and the relationships between them are analysised in immunohistochemical method (low+high level group level group) The expression and function of ADC value, respectively1H-MRS metabolite ratios and Ki-67in different grade gliomas (normal brain tissue, low level group of Ⅰ/Ⅱ and the high level group of Ⅲ/Ⅳ) are studied in statistical method, as well as the correlation between former two and the latter.ResultsHigh grade gliomas ADC value (1.21±0.18)×10-3mm2/s is lower than low grade gliomas ADC value (1.67±0.14)×10-3mm2/s, high grade gliomas ADC value is higher than the ADC value in the contralateral normal parts (0.89±0.06)×l0-3mm2/s, low grade gliomas ADC value is higher than the ADC value in the contralateral normal parts (0.88±0.04)×10-3mm2/s. High grade glioma rADC value (1.37±0.22) is lower than low grade glioma rADC value (1.91±0.19)High grade gliomas NAA/Cho value (0.31±0.14) is lower than low grade gliomas NAA/Cho value (0.82±0.12), high grade gliomas NAA/Cho value is lower than the NAA/Cho value in the contralateral normal parts (1.95±0.29), low grade gliomas NAA/Cho value is lower than the NAA/Cho value in the contralateral normal parts (2.10±0.22). High grade gliomas NAA/Cr value (1.01±0.40) is lower than low grade gliomas NAA/Cr value (2.06±0.27), high grade gliomas NAA/Cr value is lower than the NAA/Cr value in the contralateral normal parts (2.23±0.39), low grade gliomas NAA/Cr value is lower than the NAA/Cr value in the contralateral normal parts (2.38±0.26). High grade gliomas Cho/Cr value (3.39±0.37) is lower than low grade gliomas Cho/Cr value (2.54±0.26), high grade gliomas Cho/Cr value is lower than the Cho/Cr value in the contralateral normal parts (1.15±0.14), low grade gliomas Cho/Cr value is lower than the Cho/Cr value in the contralateral normal parts (1.14±0.13)High grade glioma Ki-67antigen labeling index value (0.37±0.06) is higher than low grade glioma Ki-67antigen labeling index value (0.19±0.05) significantly.In the group of high grade gliomas, Cho/Cr value and Ki-67labeling index was correlated(r=0.616, P<0.01), NAA/Cho and Ki-67labeling index was negatively correlated(r=-0.791, P<0.01), NAA/Cr and Ki-67labeling index was negatively correlated(r=-0.759, P<0.01), ADC value, rADC value and Ki-67labeling index was negatively correlated(r=-0.760、-0.837, P<0.01). In the group of low grade gliomas, Cho/Cr value and Ki-67labeling index was correlated(r=0.340, P>0.05), NAA/Cho and Ki-67labeling index was negatively correlated(r=-0.744, P<0.01), NAA/Cr and Ki-67labeling index was negatively correlated(r=-0.619, P<0.01), ADC value, rADC value and Ki-67labeling index was negatively correlated (r=-0.826、-0.792, P<0.01).Conclusions1. Multi voxel1H-MRS can accurately reflect the metabolic changes in tissue, which can provides useful information on metabolic aspects for routine imaging. Multi-voxel1H-MRS manifestations of glioma are NAA peak, Cr peak decreased, Cho peak rises significantly, NAA/Cr and NAA/Cho ratio decclined, Cho/Cr ratio increased. This study shows that with the malignant degree of gliomas increased, NAA peak has a trend of decrease and Cho peak is on the rise. When different grade gliomas were compared, Cho/Cr, NAA/Cr, NAA/Cho showed significant difference (P<0.05), helps to diagnosis the benign and malignant grading of gliomas. 2. The ADC value are significant different in entity among different grade gliomas. The difference can help for classification and secondary diagnosis.3. Ki-67in different grade gliomas express a significant difference.4. The correlation between the ratios of the metabolites, ADC values and Ki-67in solid area of gliomas are most significant. By new magnetic resonance techniques such as multi-voxel1H-MRS, DWI combined with Ki-67immunohistochemical examination, we can have a better understanding of glioma cell proliferative activity, providing new evidence on clinical diagnosis, treatment and prognosis in glioma.This study showed that multiple voxel1H-MRS and DWI check whether used alone or in combination are effective response to the proliferative activity of preoperative cerebral gliomas. They can be used in grading of cerebral gliomas diagnosis, the clinical diagnosis of glioma treatment and prognosis judgment. NAA/Cho value of the tumor tissues in1H-MRS own the highest efficiency in the diagnosis, it parallel tumor rADC screening can greatly improve the diagnostic sensitivity of the glioma cell proliferation activity. However, whether they can produce a positive impact on overall treatment effects in glioma patients, survival rates, is subject to further study. In short, with the deepening of the research and clinical application,1H-MRS and DWI can be prospectively provide useful help on glioma grading and proliferative activity, and provide more and more reliable informations for clinical.