关键词: 弥散张量成像, 弥散张量纤维束成像, 胶质瘤

Abstract: Abstract:Objective To evaluate the malignancy and invasion of gliomas preoperatively by diffusion tensor imaging(DTI),and to study the relationship between gliomas and fiber tracts by diffusion tensor tractography(DTT). Methods A total of 31 patients with grade Ⅰto Ⅳ gliomas（15 cases of gradeⅠand grade Ⅱ gliomas,16 cases of grade Ⅲ and grade Ⅳ gliomas）underwent the conventional MRI and DTI. FA map and DEC map were writen and DTT map was reconstructed in order to make comparison of the rFA values between low-grade gliomas and high-grade gliomas in relative regions of interest (ROIs),as well as to observe the changes of the white fiber tracts. Results A decreasing tendency of rFA values was observed as follow:solid portion lowest (0.428±0.078),followed by edema area(0.578±0.120) and edge of edema(0.834±0.074) in low-grade gliomas;as well as solid protion lowest(0.366±0.055)，followed by edema area(0.458±0.158) and edge of edema(0.6766±0.138) in high-grade gliomas. The rFA values of high-grade gliomas were significantly lower than those of low-grade gliomas in all ROIs(P<0.05). All gliomas presented low signals differently on FA map.The tumor region showed ambiguity and disorder on DEC map. On DTT map,3 of 15 low-grade gliomas showed deviation;the other 12 cases showed slight rarefaction;13 of 16 high-grade gliomas showed significant destruction and partly discontinuation;2 cases showed termination or interruption;1 case mainly showed deviation and part of fiber tracts showed destruction. Conclusion DTI contributes to study malignancy and invasion of gliomas and provide more useful fiber information of gliomas preoperatively.

Key words: diffusion tensor imaging, diffusion tensor tractography, glioma