摘要
背景与目的:弥散张量成像(diffusiontensorimaging,DTI)是一种高级的、定量的弥散加权成像形式,它不仅可以计算每一体素内水分子弥散的显著弥散系数(apparentdiffusioncoefficient,ADC),而且可以计算出弥散的各向异性指数。国外对脑肿瘤的研究多采用弥散加权成像,本研究采用DTI方法检测脑内星形细胞瘤患者的肿瘤实质组织、瘤内囊变坏死区、瘤周水肿与正常脑组织中ADC、部分各向异性指数(fractionalanisotropy,FA)及相对各向异性指数(relativeanisotropy,RA)值,及上述指标在星形细胞瘤分级中的价值。方法:对确诊的14例脑星形细胞瘤(1～2级10例,3～4级4例)进行DTI。测定不同组织中ADC、FA及RA值。结果:将14例脑星形细胞瘤作为一组分析时,增强的肿瘤实质组织犤(1.14±0.13)×10-3mm2/s犦、瘤内囊变坏死区犤(2.04±0.50)×10-3mm2/s犦及瘤周水肿组织犤(1.55±0.19)×10-3mm2/s犦的ADC值同正常脑组织犤(0.74±0.08)×10-3mm2/s犦相比均有显著性差异(P<0.05)。肿瘤实性部分的ADC值犤增强区域:(1.14±0.13)×10-3mm2/s,非增强区域:(1.01±0.25)×10-3mm2/s犦同瘤内囊变坏死区、瘤周水肿组织区比较均有显著性差异(P<0.05)。增强的肿瘤实质组织(FA:0.21±0.08,RA:0.23±0.07)、瘤内囊变坏死区(FA:0.14±0.06。
BACKGROUND & OBJECTIVE: Diffusion tensor imaging (DTI) is an adva nced quantitative form of diffusion-weighted imaging. It could be used to calcu late not only the apparent diffusion coefficient (ADC) of average water diffusio n for each vowel, but also the diffusion anisotropic index of diffusion. Diffusi on-weighted imaging is used in most of the studies of the brain tumors abroad. We used DTI method to measure the ADC, fractional anisotropy (FA) and relat ive anisotropy (RA), values of different tumor tissues and to evaluate the usef ulness of ADC, FA, and RA in differentiating solid tumor, necrotic region, edema region, normal brain tissue, and in grading the malignancy of cerebral astrocyt omas. METHODS: Fourteen cases of astrocytomas diagnosed (10 cases of grade 1-2 astrocytomas and 4 cases of grade 3-4 astrocytomas) were studied by DTI. ADC, F A, and RA values of different tumor tissue were measured. RESULTS: When all case s were analyzed as a group, significant differences of ADC were found in enhanci ng solid tumor (1.14±0.13×10-3 mm2/s), necrotic region (2.04±0.50×10-3 mm2 /s), edema region (1.55±0.19×10-3 mm2/s) compared with normal brain tissue (0 .74±0.08×10-3 mm2/s)(P< 0.05). Significant differences of ADC were also found in solid tumor (enhancing tissue:1.14±0.13×10-3 mm2/s, non-enhancing tissue :1.01±0.25×10-3 mm2/s) compared with necrotic region and edema region, respec tively (P< 0.05). Significant differences of FA and RA were found in solid enhan cing region (FA:0.21±0.08; RA:0.23±0.07), necrotic region (FA: 0.14±0.06, RA: 0.16±0.07), edema region (FA:0.16±0.04, RA:0.16±0.02) compared with normal b rain tissue (FA: 0.37±0.06, RA: 0.38±0.07) (P< 0.05). No difference of FA and RA was found in solid tumor (including enhancing and non-enhancing tis sue) . Significant differences of ADC (P< 0.05), not FA and RA, were found betwe en grade 1-2 astrocytomas (1.07±0.04×10-3 mm2/s) and grade 3-4 astrocytomas (1.32±0.08×10-3 mm2/s). CONCLUSION: Determination of ADC can be used to diff erentiate normal brain tissue from enhancing solid tumor, necrotic region, and e dema region. Determination of FA and RA can be used to differentiate solid enhan cing tumor, necrotic region, and edema region from normal brain tissue, but can not be used to differentiate solid tumor, necrotic region, and edema region. The ADC values, not FA and RA, may predict the degree of malignancy of astrocytic t umors.
出处
《癌症》
SCIE
CAS
CSCD
北大核心
2004年第3期317-321,共5页
Chinese Journal of Cancer
基金
广东省卫生厅基金资助(A2002207)~~
