TIA患者不同b值磁共振弥散加权成像研究  

The study of different b-values on magnetic resonance diffusion-weighted imaging in patients with TIA

作　　者：孟育飞 周存和[1] 贺丹[1] 张祥建[1] 崔彩霞[2] 苑聪聪 杨湘燕[1] 闫振[1] 

机构地区：[1]河北医科大学第二医院神经内科,石家庄市050000 [2]河北医科大学第二医院影像科,石家庄市050000

出　　处：《脑与神经疾病杂志》2017年第5期281-286,共6页Journal of Brain and Nervous Diseases

摘　　要：目的观察短暂性脑缺血发作(TIA)患者磁共振弥散加权成像(DWI)提高b值后的影像学表现,探讨TIA患者DWI高b值的临床应用价值。方法收集2014年3月至2015年3月在河北医科大学第二医院临床诊断的TIA而结构影像学(CT,MRI)无责任病灶的TIA患者44例,所有患者均在发病3 d内行常规MRI和不同b值DWI(b=1000、b=2000和b=3000)检查。比较DWI不同b值对TIA责任病灶的敏感性、病灶范围及图像伪影的影响,定量分析TIA责任病灶的体积大小、ADC值变化。结果提高DWI b值,并没有提高发现TIA患者责任病灶的敏感性,但可以发现部分病例存在更多层面的责任病灶。定性分析发现全部患者的责任病灶随着b值的提高,病灶显示更明显,在25例DWI阳性病例中有12例,12/25例患者责任病灶的范围有所增加。当b值过度提高(b=3000),会降低图像的质量,导致伪影加重,而不易区分真正的责任病灶。定量分析发现随着b值的提高,责任病灶的平均体积也在增加(P<0.05),而ADC值却在下降(P<0.05)。结论提高DWI b值(b=2000,b=3000)更有助于反应TIA患者责任病灶的体积,有助于发现潜在的微小的不易发现的病灶,但b值过度提高(b=3000)会降低图像的质量,因此建议取DWI(b=2000)对诊断及评估TIA患者更有优势。Objective To observe the diffenent imaging findings on diffusion-weighted imaging （ DWI ） in patients with transient ischemic attack （ TIA ） by increasing the b-values, in order to evalueate the clinical value of high b-values on DWI. Method Forty-four patients with TIA from the 2nd Hospital of Hebei Medical University were selected. All patients underwent the same imaging examination within three days after the symptom onset that included conventional MRI （ cMRI ） and DWI with different b-values （ b=1000, b=2000, b=3000 ） . The differences in DWI with different b-values （ b=1000, b=2000 and b=3000 ） about lesion conspicuity,lesion extent and image artifact were observed;The lesion volume,apparent diffusion coefficient （ ADC ） values were quantitative analyzed on the DWI images. Results DWI with high b-value did not increase the sensitivity for the detection of related brain lesion in TIA patients.but in some cases,responsibility lesions were founded in more slices.Qualitative analysis showd that lesions were more conspicuous in all TIA patients.The lesion size were larger in twelve cases,similar in nine cases because of the too small infarction or lacunar infarction. But excessively increased b-value affected the quality of the image.The image artifacts resulted in hyperintensive area,which was very difficult to distinguish from the restricted diffusion area after acute infarction.With the b-value increased,The qualitative analysis showed that the mean lesion volume increased （P〈0.05 ） ,while the ADC-value decreased （P〈0.05 ） .Conclusion Using higher b-value on DWI can be beneficial in evaluating the real related brain lesion volume and may still be beneficial in detecting the subtle tiny lesions,but the excessively increase of the b-value will reduce the quality of the image.DWI with b=2000 second/ mm2 has the superiority than the other b-values for detection of patients with TIA.

关 键 词：短暂性脑缺血发作 磁共振成像 弥散加权成像 B值 

分 类 号：R743.32[医药卫生—神经病学与精神病学]