摘要
目的:应用新生儿缺氧缺血性脑病(HIE)动物模型,探讨HIE早期弥散加权像(DWI)、表观弥散系数(ADC)图影像动态演变规律。方法:3天龄新生猪随机分为正常对照组、假手术组和缺氧缺血组。缺氧缺血组动物结扎双侧颈总动脉,3%O2混合气体吸入30分钟。采用1.5T磁共振仪,进行DWI和T2WI检查;应用FuncTool软件生成ADC图,测量各组病灶中心区和周边区的ADC值。结果:缺氧缺血组动物缺氧时出现四肢抽搐、竖尾、角弓反张等体征,HE染色神经元有变性、坏死。缺氧缺血后3小时DWI上出现高信号,ADC图低信号灶,随缺氧缺血后时间的延长病灶范围扩大。病变各中心区ADC值呈明显下降趋势,各组P<0.01;周边区ADC值3～6小时P>0.05,6小时与24小时ADC值比较P<0.01;各组中心区和周边区ADC值比较P<0.01。结论:①DWI结合ADC图可以敏感地显示HIE病灶。②ADC值的动态变化结合组织病理学改变提示早期HIE病灶内尚存可逆的脑组织区域。
Objective: To explore the early findings of HIE with diffusion weighted imaging and apparent diffusion coefficient. Materials and Methods: Nineteen newborn pigs were divided into five groups as follows: normal control group(n=2), sham operation group(n=2), 3 hours after cerebral hypoxic-ischemia group(n=5), 6 hours after cerebral hypoxic-ischemia group(n=5), and 24 hours after cerebral hypoxic-ischemia group(n=5). The model of cerebral hypoxic-ischemia was made by occlusion of bilateral common carotid arteries, then inspiration of 3% oxygen for 30 minutes. T2WI and diffusion-weighted images (DWI) were performed on a 1.5T Magnet scanner at various time point. For DWI, b values of 0 and 1000s/mm2 were used. Apparent diffusion coefficient(ADC) values were measured in the central regions and peripheral regions of lesions. Results: Abnormal signal intensity was detected on DWI and ADC maps in all three hypoxic-ischemia groups. ADC values in the central lesions were (0.556±0.065)×10-3mm2/s, (0.466±0.059)×10-3mm2/s, (0.371±0.023)×10-3mm2/s for the three hypoxic-ischemia groups respectively. ADC values in the peripheral regions were (0.817±0.069)×10-3mm2/s, (0.793±0.062)×10-3mm2/s, (0.534±0.039)×10-3mm2/s, respectively. There were significant statistical differences(P<0.01) between ADC values of the central regions and those of the peripheral regions. Conclusion: Compared with T2WI, DWI and ADC maps can be utilized to identify more early lesions, and improve conspicuity of hypoxic-ischemic injury. ADC values can be used as an objective measure for hypoxic-ischemic injury. Cerebral tissue damage reversibility could be further reflected with the information of ADC values.
出处
《中国临床医学影像杂志》
CAS
2004年第10期541-544,共4页
Journal of China Clinic Medical Imaging
