The Application Value Of Diffusion Tensor Imaging And Diffusion Tensor Tractography In Diagnosis Of Brain Tumors

Objective To discuss the value of DTI and diffusion tensor tractography (DTT) in thediagnosis and differential diagnosis in the solid part of Astrocytoma and Meningiomaimaging.Through measured and analysised ADC and FA in the tumor parenchyma region,observed therelationship between alba and fiber bundle,and provide more useful information for clinicaldiagnosis.Methods22patients with pathologically proven brain tumor, different gradeastrocytomas in12cases,10cases of benign meningiomas,To measure the ADC value andFA value in the tumor parenchyma and corresponding contralateral normal brain tissue on theaverage ADC and FA diagrams.Analysis the differences of the average ADC value and FAvalue between the two kinds of tumors. To observe cerebral white matter fiber bundleeffect of the two tumors.Results Astrocytoma or meningioma tumor parenchyma within the patient groupcompared with the contralateral normal brain tissue, FA values were significantly different(P<0.05), and higher than normal brain tissue; astrocytoma tumor parenchyma of patientsADC values than normal brain tissue high, the difference was statistically significant(P<0.05). Meningioma tumor parenchyma compared with the contralateral normal part ofADC values was no significant difference (P>0.05). Astrocytoma group of patients withmeningioma tumor parenchyma ADC values, FA values were significantly differentcompared (P<0.05). Astrocytoma mostly illustrated on DTT is partial disruption, compression,deviation and displacement of fiber bundles;Most of the meningioma fiberbundles showed significant rarefaction and displacement.Conclusion Measurement of tumor parenchyma ADC values and FA values can beused to identify the astrocytoma and meningioma. DTT can clearly show the normal whitematter fiber tracts and tumor anatomy, therefore it is conducive to the development ofpreoperative program. Objective To discuss the values of DTI and diffusion tensor tractography (DTT) inthe diagnosis and differential diagnosis in the solid part and Peri-tumoral Regions betweenhigh-and low-grade intracranial astrocytoma. Through measured and analysised ADC and FAin the tumor parenchyma region, peri-tumoral region and corresponding contralateral normalbrain tissue,observed the relationship between alba and fiber bundle,and provide more usefulinformation for clinical diagnosis.Methods The conventional MR imaging and diffusion tensor imaging (DTI) wereperformed on30cases Astrocytoma (including14cases with low-grade Astrocytoma,WHOⅠ~Ⅱ,16cases with high-grade Astrocytoma, WHOⅢ~Ⅳ) before treatments oroperations between October,2010and March,2011. Measured and analysised ADC and FA inthe tumor parenchyma region, peri-tumoral region (the area with a distant of1.5cm) andcorresponding contralateral normal brain tissue. Analysis the differences of the average ADCvalues and FA values between the two grades of astrocytomas. To observe cerebral whitematter fiber bundle effect of the two grades of astrocytomas. The diagnoses wereconfirmed surgically and pathologically in all cases with brain tumors. DTI were performedusing single shot SE-EPI sequence with two different b values (0s/mm2and1500s/mm2).DTI were performed immediately before Gd-DTPA intravenous adminstration injection. Thedata measured from DTI were calculated and analyzed,and then statistical analyses wereperformed by using the software of SPSS11.0. Results (1) Routine MRI and DTI can show clearly the tumors of all patients.Signalintensity of tumor parenchyma region,peri-tumoral region and normal brain tissue wereobviously different in ADC and FA maps.(2) FA values of tumor parenchyma and peri-tumoral region between low-grade andhigh-grade astrocytoma had difference (P<0.05), ADC values of high-grade astrocytoma hadsignificant difference (P<0.05),ADC values were not significantly different betweenlow-grade and high-grade astrocytoma (P>0.05).(3) FA values and ADC values of tumor parenchyma and peri-tumoral region ofhigh-grade astrocytoma were lower than that of low-grade. Compared with the contralateralnormal brain tissue,FA values and ADC values of tumor parenchyma and peri-tumoral regionwere obvious lower.(4) On DTT map of low-grade astrocytoma,the white matter tract mainly showedsignificant rarefaction and displacement fiber bundles,displacement with well-definedborder,whereas invasion and infiltration of the white matter tract with relatively ill-definedborder were showed in high-grade astrocytoma. On DTT map of high-grade astrocytoma,showd partial disruption,compression,deviation and displacement fiber bundles.Conclusions (1) Measurement of tumor parenchyma and peri-tumoral region FAvalues can be used to identify high-and low-grade intracranial astrocytoma,it can be used topredict the grades of astrocytoma before surgery.(2)ADC values can distinguish tumorparenchyma between peri-tumoral region in some degree.(3) DTT can clearly show thenormal white matter fiber tracts and tumor anatomy of different gradesastrocytoma,therefore it is conducive to the development of preoperative program.