The Value Of Differentiation Between Ependymoma And Low-leve Astrocytomas With DWI And ADC Value

Obj ective:Through analyzing the trait of diffusion weighted imaging (DWI) signal and apparent diffusion coefficient (ADC) value in ependymoma and low-grade astrocytomas, comparing the differences between the two tumours, discusses the value of differentiation between ependymoma and low-grade astrocytomas with DWI and ADC value.Merhods:Retrospective analysis the patients from January 2007 to December 2014 in our hospital who had head MRI scan enhanced scanning and the head of DWI check and confirmed by postoperative pathology,including ependymoma,12 patients (WHO Ⅱ),16 cases of Low-leve astrocytoma (WHO Ⅱ). All patients with demand MRI T1WI, T2WI scanning and DWI scan.Ependymoma 7 cases of male patients, other 5 cases were women, age distribution in 12～59, an average of 42.17 years old;Low-level astrocytoma 12 cases of men,4 cases of women, age distribution in the 27～67, 43.88, on average.Use type GE 1.5T or 3.0 T superconducting magnetic resonance imaging system,the head coil.All patients were used conventional axial T1WI,T2WI, sagittal T1WI, strengthen the axial and sagittal and coronal TWI and DWI scanning.Enhanced scan with paramagnetic contrast medium injection for pt acid ammonium(GD-DTPA),dose tendency for 0.1kg weight.DWI scans the SE-can EPI sequence,b=1000s/mm2,with functool function software ADC values in diffusion weighted image measuring, Experimental group defined two groups, got the ADC values of tumor essence part of tumor patients.The ADC values is an average ADC values obtained form three random parts.Wall to avoid tumor necrosis, cystic change and calcification and part of the control group in patients with tumors of the contralateral corresponding normal part of the brain, measured the size of ADC values, method with the former.By comparing the analysis ependymoma tumor essence part and low-level astrocytoma tumor essence part change of DWI signal performance and the ADC figure the difference of ADC values for statistical analysis. Set ependymoma and astrocytoma as experimental group, with a low level of the contralateral normal brain tissue for the control group, experimental group and control group respectively match test. Application samples of opposites between the experimental group t test, two sets of data through SPSS2.1 software, complete statistical analysis.Results:1. Conventional MRI and DWI manifestations:ependymoma tumor essence part T1WI characterized by low signal, T2WI characterized by nonuniform high signal,DWI characterized by slightly higher or high signal, ADC showed by equality or little low signal.Low-level astrocytoma tumor essence part T1WI characterized by slightly low or low signal, T2WI showed by high signal, DWI characterized by equality or slightly high signal, ADC characterized by slightly high Signal.2. ADC values:The average ADC values for all ependymoma tumor substantial part was (1.11±0.09)×10-3mm2/s,comparison between ependymoma tumor substantial part groups and control group was significant difference(P<0.01);While that the average ADC values for all low-level astrocytoma tumor essence part was (1.48± 0.11)×10-3mm2/s, comparison between low-level astrocytoma tumor essence part groups and control group was significant difference(P<0.01);.Ependymoma and low-level astrocytoma through independent sample test (P<0.01), they had significant difference.Conclusion:Magnetic resonance diffusion weighted imaging (DWI) is currently testing the most ideal method of water molecular diffusion movement in living tissue. Apparent diffusion coefficient (ADC) is reflected the diffuse speed and scope of free water molecules from different directions on DWI figure, ADC values is calculated according to the change of signal intensity on DWI figure can. Ependymoma and Low-leve astrocytomas sometimes are difficult to identify. Its performance on the speed and degree of water molecules floating freely in all directions, and the ADC figure. The earliest application is carried out in the early diagnosis of cerebral infarction, With the constant improvement of the MRI technology, tumor pathological diagnosis of DWI in other parts of the body can value more and more attention by people, Especially early on in qualitative diagnosis of intracranial lesions occupied its role in the future will be more and more people realize that. The differential diagnosis of Ependymoma and low leve astrocytomas sometimes it is difficult to rely on conventional imaging studies to complete. But, due to the different origin, histological aspects and liquid properties, it can be shown on DWI and ADC values values.Comparing DWI and ADC values, when tumor substantial part DWI characterized by slightly higher or high signal, ADC characterized by etc or slightly low signal, can consider ependymoma. When tumor essence part of DWI shows etc or slightly high signal, ADC shows slightly higher signal, can consider to low-level of astrocytoma. DWI and ADC values has a extremely value for differentiating two kinds of tumors, especially for Ependymoma and Low-leve astrocytomas in the intracranial.