Sase Ichiro, Takatsuki Akira, Seki Junji, Yanagida Toshio, Seiyama Akitoshi
National Institute of Information and Communications Technology, Kansai Advanced Research Center, Brain Information Group, Kobe, Hyogo 651-2492, Japan.
J Biomed Opt. 2006 Sep-Oct;11(5):054006. doi: 10.1117/1.2363359.
To improve the spatial resolution and to obtain the depth information of absorbers buried in highly scattering material, we developed a noncontact backscatter-mode near-infrared time-resolved imaging system (noncontact B-TRIS) that is intended for functional human brain mapping. It consists of mode-locked Ti-sapphire lasers as light sources and a charge-coupled device camera equipped with a time-resolved intensifier as a detector. The system was tested with a white polyacetal phantom as a light-scattering medium and black polyacetal particles as absorbers. Illumination and detection of light through an objective lens system (phi = 150 mm) enabled us to capture images from an area whose diameter is about 70 mm without coming into contact with it. The scattering and absorption coefficients of the white phantom obtained by B-TRIS were similar to those obtained by a conventional time-resolved spectroscopy. Although the imaged diameter of an absorber buried within a phantom was considerably larger than the actual diameter, the center position of the absorber coincided with the actual position with accuracy <2 mm. Furthermore, the depth information can be also detected by the noncontact B-TRIS. These results suggest a potential of noncontact B-TRIS for imaging cognitive human brain function.
为了提高空间分辨率并获取埋藏在高散射材料中的吸收体的深度信息，我们开发了一种用于功能性人脑图谱绘制的非接触背散射模式近红外时间分辨成像系统（非接触B-TRIS）。它由锁模钛宝石激光器作为光源和配备时间分辨增强器的电荷耦合器件相机作为探测器组成。该系统以白色聚甲醛体模作为光散射介质，黑色聚甲醛颗粒作为吸收体进行了测试。通过物镜系统（φ = 150 mm）进行光的照明和检测，使我们能够从直径约70 mm的区域捕获图像而无需与之接触。通过B-TRIS获得的白色体模的散射和吸收系数与通过传统时间分辨光谱法获得的系数相似。尽管埋藏在体模内的吸收体的成像直径明显大于实际直径，但吸收体的中心位置与实际位置精确重合，精度<2 mm。此外，非接触B-TRIS还可以检测深度信息。这些结果表明非接触B-TRIS在成像人类认知脑功能方面具有潜力。
