论文部分内容阅读
目的利用磁共振成像(MRI)技术探讨糖尿病视网膜病变患者在吸入100%纯氧后视网膜氧合反应(ΔPO_2)的变化规律。设计前瞻性病例对照研究。研究对象6例糖尿病患者及年龄相匹配的6例健康受试者。方法应用GE 1.5T磁共振扫描仪对研究对象先后间断吸入室内空气和100%纯氧进行数据采集,扫描时间持续约50分钟。NIHIMAGE软件包用于数据分析。主要指标视网膜前玻璃体信号强度、ΔPO_2。结果健康受试者整个视网膜的ΔPO_2空间变化是非均一的。在高浓度吸氧状态下初期,健康受试者视乳头区的视网膜前玻璃体信号强度迅速增高,而视网膜颞侧及鼻侧区信号强度不同程度下降。随着吸氧时间延长,各部位视网膜前玻璃体信号强度略有波动,但趋向逐渐增高。任一时间点的ΔPO_2与其余时相间比较,差异均无统计学意义(P均>0.05)。糖尿病组,视网膜前玻璃体的信号强度持续增高,且显著高于对照组(P均<0.05)。高浓度吸氧结束后,健康受试者非视乳头区域视网膜前玻璃体信号强度呈不同程度的延迟强化效应。随后,各区域ΔPO_2均迅速下降。而糖尿病组患者在吸氧结束后其ΔPO_2迅速下降。对照组ΔPO_2与年龄呈显著线性正相关。结论高浓度吸氧能够诱导视网膜前玻璃体区域特异性的信号变化。糖尿病患者ΔPO_2升高可能与视网膜血管调节异常有关。MRI可作为探测视网膜病理状态下氧合反应机制的有效工具。
Objective To investigate the changes of retinal oxygenation (ΔPO_2) in patients with diabetic retinopathy after inhalation of 100% pure oxygen using magnetic resonance imaging (MRI). Design prospective case-control study. Subjects Six patients with diabetes and age matched 6 healthy subjects. Methods The GE 1.5T magnetic resonance scanner was used to collect the data of intermittent inhalation of indoor air and 100% pure oxygen. The scanning time lasted about 50 minutes. NIHIMAGE software package for data analysis. The main index retinal previtrial vitreous signal intensity, ΔPO_2. Results The spatial variation of ΔPO_2 throughout the retina of healthy subjects was non-uniform. In the initial stage of high oxygen concentration, the signal intensity of the pre-retinal vitreous in the optic disc region of healthy subjects increased rapidly, while the signal intensity of the temporal and nasal regions of the retina decreased in varying degrees. With the prolonged oxygen inhalation time, the signal intensity of the anterior vitreous in each part fluctuated slightly, but the trend tended to increase gradually. There was no significant difference in ΔPO_2 between the two time points (P> 0.05) at any time point. The signal intensity of diabetic group and pre-retinal vitreous body continued to increase, which was significantly higher than that of the control group (all P <0.05). After high-concentration oxygen inhalation, the signal intensity of the pre-retinal vitreous in the non-optic region of healthy subjects showed different degree of delayed-enhancement effect. Subsequently, ΔPO_2 decreased rapidly in all regions. In the diabetic group, the ΔPO_2 decreased rapidly after the oxygen inhalation. There was a significant linear positive correlation between ΔPO_2 and age in the control group. Conclusion High concentration of oxygen can induce the signal changes in the region of the anterior vitreous of the retina. Diabetic patients with elevated ΔPO_2 may be related to abnormal retinal vascular regulation. MRI can be used as an effective tool to detect the mechanism of oxygenation in retinal pathology.