不同b值弥散加权成像对亚急性早期脑梗塞的诊断价值  

Diagnosis value in early subacute cerebral infarction of different b values on diffusion-weighted imaging(DWI)

作　　者：张冰茜[1] 高燕[1] 樊树峰[1] 王浩初[1] 

机构地区：[1]浙江省台州医院放射科,浙江台州317000

出　　处：《医学影像学杂志》2007年第1期28-31,共4页Journal of Medical Imaging

摘　　要：目的：通过双b值DWI对比（b=1000s／mm^2，2000s／mm^2），研究高b值对亚急性早期脑梗塞诊断价值。方法：回顾性研究发病时间3～6天30例患者（平均年龄67岁），1．5MR进行传统MR序列及双b值DWI，然后在工作站上图像后处理。感兴趣区定为病灶中心与对侧正常部位。测量并计算ADC与相对ADC（rADC）。结果：和b=1000s／mm^2，DWI（DWI b1000）相比，b=2000s／mm^2 DWI（DWI b2000）脑灰白质对比度增加，也能发现新病灶，原有病灶更加显著：随着b值增加，正常脑组织和病变的信号强度、ADC均出现降低；不同b值比较下，同侧ADCP〈0．05．有统计学意义；同侧与对侧平均信号强度、相对信号强度及对侧ADCP〈0．005，均有显著统计学意义。结论：DWI对梗塞灶的检测明显优于T2 flair，能发现T2 flair不明显的病灶，随b值增加，病灶信号对比度增加，能进一步发现新病灶。Objective：To evaluate the diagnosis value in subacute brain infarction of high-b-value diffusion-weighted magnetic resonance imaging（DWI） through double b value DWI study （b= 1000s,/mm^2, 2000s/mm^2）. Methods： Retruspective analysis of 1.5T MB exarmination conventional and double value serial findings in 30 subjects （age average,67 years） 3 - 6 days after onset. Neuroimaging was analyzed on workstation all. Apparent diffusion coefficient （ADC） and relative ADC were measured in ROI which were placed on infarcted lesion and symmetrical eontralateral normal brain tissue. Results：Compared to DWI b1000,DWI b2000 could improve the contrast of the grey and white matter, and find new unseen lesion. The b value increased, the ADC and rADC values decl/ned and former lesions became significant. No significant change of relative ADC values was found between different b value groups （ P 〉 0.05 ）. The isolateral and contralateral signal intensitiy , ADC and relative SI were significantly different between DWI at b value 1000 s / mm^2 and 2000 s / mm^2 （ P 〈 0.05）. Conclusion：DWI was superior to T2 flair in displaying the lesions,and find new lesions unseen on T2 flair. With the b value increased, the contrast hetwecn the/sehemlc and normal brain tissue became distinct, which was helpful to find new lesions further.

关 键 词：脑梗塞 弥散 B值 磁共振成像 

分 类 号：R743.33[医药卫生—神经病学与精神病学] R445.2[医药卫生—临床医学]