The Role Of Magnetic Resonance Diffusion Tensor Imaging In Differential Diagnosis Of Intracranial Tumors

Part Ⅰ:The Value of Diffusion Tensor Imaging in Differentiating Atypical Meningioma from Astrocytic tumoursObjective:To determine whether the atypical meningioma from astrocytic tumours can be differentiated by diffusion tensor MR imaging. Methods: Diffusion tensor MR imaging was performed preoperatively in all patients with 17 atypical meningioma and 28 different astrocytic tumours. The Apparent diffusion coefficient (ADC) and Fractional anisotropy (FA) values in the tumor parenchyma, peritumoral region and normal white matter from the atypical meningioma and astrocytic tumours were measured and analyzed. The ADC and FA with the tumor parenchyma, peritumoral region and normal white matter from the tumours were statistically analyzed by SPSS19.0. The P<0.05 was regarded as statistically differences. Results: There were many differences with FA in parenchyma, peritumoral region and corresponding contralateral normal brain tissue between atypical meningioma (0.23±0.05,0.20±0.04,0.28±0.04) from astrocytic tumours (0.05±0.01、0.14±0.03、0.26±0.04). There were also many differences with ADC (X 10-9mm2/s) in parenchyma, peritumoral region and corresponding contralateral normal brain tissue between atypical meningioma (0.82± 0.13、1.22±0.32、0.73±0.10) from astrocytic tumours (1.58±0.17、 1.41±0.10、0.70±0.06). Conclusion:Measurement of tumor parenchyma and peritumoral region’s FA values and ADC values can identify atypical meningioma and astrocytic tumours. DTI is essential to preoperative evalution of the atypical meningioma from astrocytic tumours.Part Ⅱ:The Role of Diffusion Tensor Imaging in Differential Diagnosis of Different Subtypes of Astrocytic tumorsObjective:To determine whether the different pathological types of astrocytic tumours can be differentiated by diffusion tensor MR imaging. Materials and methods:In this study, diffusion tensor MR imaging was performed preoperatively in 67 patients with different pathological types of astrocytic tumours. Furthermore, T1WI, T2WI、FLAIR and T1WI enhancement scanning by GD-DTPA were performed preoperatively in all patients. The Mean diffusivity (ADC) values in the tumor parenchyma and normal white matter from different pathological types of astrocytic tumours were measured and analyzed. The ADC with the tumor parenchyma and normal white matter from the tumours were statistically analyzed by SPSS19.0. P<0.05 was regarded as statistically significant differences. Results:There were many differences with ADC (×10-9mm2/s) in the tumor parenchyma between fibrillary astrocytoma (1.48±0.12、0.72±0.05) from fat cell astrocytoma (1.31±0.07、0.69±0.03); There were also many differences with ADC (X 10-9mm2/s) in the tumor parenchyma between fibrillary and fat cell astrocytoma from anaplastic astrocytoma (1.06±0.11、0.71±0.04) and giant cell glioblastoma (0.98±0.09、0.73±0.04); There were not differences with ADC in the tumor parenchyma between anaplastic astrocytoma from giant cell gliobastona. Conclusion:Measurement of tumor parenchyma’s ADC values can identify different pathological types of astrocytic tumours, but not between anaplastic astrocytoma and giant cell glioblastoma. DTI is essential to preoperative evalution of astrocytic tumours.