Objective: To develop a near-infrared fluorescence imaging system based on the fluorescence properties of methylene blue.
Methods: According to the optical properties of methylene blue, we used a custom-made specific LED light source and an interference filter, a CCD camera and other relevant components to construct the near-infrared fluorescence imaging system. We tested the signal-to-background ratio (SBR) of this imaging system for detecting methylene blue under different experimental conditions and analyzed the SBR in urine samples collected from 15 Wistar rats with intravenous injection of methylene blue at the doses of 0, 1.4, 1.6, 1.8, or 2.0 0 mg/kg methylene blue.
Results: The SBR of this imaging system for detecting methylene blue was affected by the concentration of methylene blue and the distance from the sample (P<0.05). In the urine samples from Wistar rats, the SBR varied with the the injection dose, and the rats injected with 1.6 mg/kg methylene blue showed the highest SBR (8.71∓0.20) in the urine (P<0.05).
Conclusion: This near-infrared fluorescence imaging system is useful for fluorescence detection of methylene blue and can be used for real-time recognition of ureters during abdominal surgery.
目的: 基于亚甲基蓝的荧光特性研制近红外荧光成像系统并开展相关实验以证实该系统的可行性。
方法: 首先，根据亚甲基蓝的光学特性，分别定制特定LED光源与干涉滤光片，及CCD相机等相关的零部件，并进行近红外荧光成像设备的搭建。其次，利用研制的近红外荧光成像系统进行亚甲基蓝近红外荧光成像实验，并分析计算各种不同实验条件下的亚甲基蓝的SBR（Signal-to-background ratio）值及进行数据统计分析。最后，初步开展wistar鼠尿液收集实验，15只wistar鼠随机分成5组，每组分别给予尾静脉注射不同剂量的亚甲基蓝注射液（剂量分别为0、2、1.8、1.6、1.4 mg/kg），收集尿液，并将收集的尿液进行近红外荧光成像及分析各个剂量组的SBR值，并采用单因素方差分析。
结果: MB的SBR值受浓度及成像距离的影响，各种不同实验条件下P值均小于0.05。而不同剂量组wistar鼠尿液的SBR值随剂量的减小呈现先增大后减小，其中1.6 mg/kg的剂量组SBR值（8.71±0.20）最高，且不同剂量与SBR值具有显著性差异（P < 0.05）。
结论: 该系统可用于亚甲基蓝荧光的探测，有望进一步应用于腹部术中输尿管实时识别的研究。