磁共振弥散加权像在脑脓肿诊断中的临床应用价值  

Clinical Values of DWI in Diagnosis of Brain Abscesses

作　　者：黄敏华[1] 郭勇[1] 林伟[1] 钱明珠[1] 张永文[1] 

机构地区：[1]海军总医院医学影像科,北京100037

出　　处：《海军总医院学报》2007年第3期145-148,共4页Journal of Naval General Hospital of PLA

摘　　要：目的研究磁共振弥散加权像及表观弥散系数值在鉴别脑脓肿与坏死囊变脑转移瘤中的应用价值。方法病理及临床证实脑脓肿14例,坏死囊变脑转移瘤17例,经常规磁共振检查及弥散加权检查,在脑脓肿脑炎期、包膜期及吸收期进行弥散信号及表观弥散系数值的测量,并与坏死囊变脑转移瘤相比较。结果脑脓肿包膜期弥散加权像为高信号,表观弥散系数值低,与坏死囊变脑转移瘤弥散加权像及表观弥散系数值正好相反。吸收期及脑炎期脑脓肿弥散加权像为低信号或等信号,而表观弥散系数值为高信号,与坏死囊变脑转移瘤正好相类似。所有脑脓肿的平均表观弥散系数值为0.88×10-3mm2/s,坏死囊变脑转移瘤平均表观弥散系数值1.8×10-3mm2/s,两者比较有显著性差异(P<0.05)。弥散加权像信号诊断的敏感性为64.5%(20/31),特异性为100%(17/17),准确性为77.0%(37/48)。结论弥散加权像及表观弥散系数值有助于鉴别包膜期脑脓肿与坏死囊变脑转移瘤,对吸收期脑脓肿与坏死囊变脑转移瘤的鉴别诊断无明显意义。Objective To study the values of diffusion-weighted imaging （DWI）and apparent diffusion coefficient （ADC） in the differential diagnosis between brain abscesses and necrotic or cystic metastatic brain tumors. Methods Pathologically proved 14 patients with brain abscess and 17 patients with cystic/necrotic metastatic tumor underwent conventional MRI and DWI examinations. DWI signal and ADC value were evaluated in cerebratis stage, capsule formation stage, and evolution stage of brain abscess and compared with those of cystic/necrotic metastatic tumor. Chi-squared test and t test were performed for Statistic analysis. Results The DWI signal was high and ADC value was low in the capsule stage of abscess,which was contrary to that of cystic/necrotic tumor. The DWI signal was low or equal and ADC value was high or equal in the evolution stage or cerebritis stage,which was similar to that of cystic/necrotic tumor. The mean ADC value of all brain abscesses was （0. 88 × 10^-3 ） mm^2/s, and that of cystic/necrotic tumor was （1.8 × 10^-3 ） mm^2/s; the difference was statistically significant （P〈0.05）. The diagnostic sensitivity, specificity and accuracy of DWI signals was 64.5%（20/31） ,100%（17/17） and 77.0%（37/48） respectively. Conclusion DWI and ADC value are helpful to differentiate between capsule formation stage of abscess and cystic/necrotic tumor ,but not helpful to distinguish between evolution stage/ cerebrites stage of abscess and cystic/necrotic tumor.

关 键 词：磁共振成像 弥散加权成像 表观弥散系数值 脑脓肿 脑转移瘤 

分 类 号：R445.2[医药卫生—影像医学与核医学]