| [Objective] To observe the activating differences between bilateral primary motor area (Ml) in patients with brain tumors by using blood oxygenation level dependent functional magnetic resonance imaging (BOLD-fMRI) with hand motion. To analyse the influence of types and diameter of brain tumor, distance between the tumor and Ml, displacement of the Ml on BOLD signal in Ml. To compare and analyze the differences of the BOLD signal in Ml among different types of tumor. To observe the BOLD signal changes in Ml pre- and postoperation.To visualize the relationship among brain tumors activating Ml and corticospinal tract (CST) by combination of BOLD-fMRI and diffusion tensor imaging (DTI).[Materials and Methods] Thirty-two patients with brain tumors located within or near the pre- or postcentral gyrus, including 8 high-grade gliomas (WHO grade III-IV), 8 low-grade gliomas(WHO grade I - II ),8 metastatic tumors (MT) and 6 meningiomas (WHO grade I-II), 1 lymphadenoma, 1 hemangio-perithelioma. Different groups were subdivided according to the type,grade, location, original of the brain tumors. The patients were classified into three groups according to the types, including glioma group (astrocytoma and oligodendroglioma, n=16), meningioma groups(n=6), MT group(n=8). Only one case of lymphadenoma and hemangio-perithelioma respectively, which were excluded in these groups. According to the grade of brain tumors on WHO, the patients were classified into two groups, 18 cases of high-grade brain tumors (8 cases of high-grade gliomas, 8 cases MT, 1 case of lymphadenoma and hemangio-perithelioma respectively, WHO III-IV) and 14 casesof low-grade brain tumors (8 cases of low-grade gliomas, 6 cases of meningioma, WHO I-II).Intracranial tumors (ICT) and extraaxial tumors were subdivided according to the location of the brain tumors in this study, that is 25 cases of intracranial tumors (gliomas in 16 cases, MT in 8 cases, lymphadenoma in one case) and 7 cases of extraaxial tumors(meningioma in 6 cases, hemangio-perithelioma in 1 case);According to the original of the intracranial tumors, 17 cases of primary brain tumor group (gliomas in 16 cases, lymphadenoma in one case ) and secondary tumor group (MT in 8 cases) were subdivided in this study. 10 cases of matched healthy adult were selected as control group. All subjects were examined with GE 1.5T MR scanner and 8-channel head coil. Axial Tl-flair images were obtained. EPI functional MR imaging were acquired at the same slices with Tl-flair images. FA imaging were calculated by DTV1.5,3D white matter tract, brain tumor and functional areas were merged together by Volum One.[Results] There was no statisticaly significant difference on signal intensity among the different types of the tumor (F=2.53, P=0.07). But on the activated extent, there were statisticaly significant difference among groups (F=8.51, P=0.00). The statistical result showed that there was significant difference between the control group and the glioma group, the control group and the MT group, the glioma group and the MT group, the MT group and the meningioma group (P=0.01, P=0.00, P=0.01, P = 0.01 respectively). The BOLD signal intensity and extent were statistically different among tumors with different grades (F=7.59, P — 0.002;F=24.12, P=0.00). The statistical results showed that there was significant difference between the control group and high-grade brain tumor group (Pjntensity, P\ = 0.01, ■^extent, Pe=0.00), the high-grade brain tumor group and the low-grade brain tumor group (Pj = 0.00, Pe=0.00), the control group and the high-grade glioma group (Pj = 0.01, Pe=0.00), the high-grade glioma group and the low-grade glioma group {P\— 0.01, Pe=0.00). The BOLD signal intensity and extent were statistically different among the tumors with different locations (F=3.53, P=0.04;F=7.47, P=0.00). Thestatistical results showed that there were significant difference between the control group and the ICT group (A=0.04, Pe=0.00), The ICT group and the extra-axial tumor group (P\=0.04, Pt=0.00). There was no significant difference according to the origin of the ICT on the BOLD signal intensity (F=2.01, P=0.\5). Take the BOLD signal extent for granted, there was significant difference between two groups (F=10.24,P=0.00). The statistical results showed that there was statistial difference between the control group and the primary brain tumor group, the control group and the secondary tumor group, the primary and secondary tumor group (P=0.01, P= 0.00, P=0.02).With stepwise multiple regression, mutiple factors, including the tumor diameter, distance of the tumor to the Ml, the displacement of the Ml, as well as the type, grade, location, and original of the brain tumors were analyzed in statistical model, which showed the major factor influenceing the BOLD signal intensity was the grade of brain tumors and the major factors influenceing the BOLD signal extent were the grade of brain tumors on WHO as well as the displacement of the Ml.The signal intensity and extent in Ml increased generally in the postoperation compared with that in the pre- operation, especially in malignant tumor groups.The relationships among brain tumors, Ml, CST could be visualized directly on the combined images of BOLD-MRI imaging and diffusion tensor tractography (DTT), and were helpful for making operative planning.[Conclusion] l.The brain tumors adjacent to the Ml could affect the BOLD signal intensity and extent and there was statistiaclly significant differences among the tumors with different types, grades, locations, and original.2.The major influence factor on BOLD signal intensity was the grade of brain tumors on WHO;the major influence factors on BOLD signal extent were the grade of brain tumors on WHO as well as the displacement of the Ml.Other factors, such as the tumor diameter, distance of the tumor to the Ml, the type and location of the brain tumors were not the major influence factor.3.The signal intensity and extent in Ml increased generally in the postoperation compared with that in the pre- operation, especially in malignant tumor groups. The result implied that the Ml recoveried partially after operation and the BOLD-fMRI can be used to evaluate the effectiveness of the operation.4.DTT three-dimensional reconstruction of CST merged with brain tumor and BOLD-fMRI in Ml could directly visualize the relationships among brain tumors, Ml, CST and was helpful for making surgery planning. |
PDF Full Text Request