Three Dimensional Image of Regional Brain Tissue Hemoglobin and Its Oxygen Saturation by using Near Infra Red Light.

我们一直在努力利用两个波长的近红外光（NIR）来制作大鼠脑血红蛋白的氧饱和度图像，这两个波长的近红外光只给出氧饱和度等比值。本研究采用三种波长的近红外，获得了总血红蛋白及其饱和度图像。在第一年，我们将该方法应用于缺氧脑模型，以评估该方法的有效性，并相继得到脱氧血红蛋白升高和氧合血红蛋白降低的下限FIO_2 （7.5% O_2）。第二年，我们将该方法应用于大鼠脑梗死模型，获得了清晰显示梗死军团的血红蛋白图像。这些结果表明，光学成像方法在无创检测脑氧合状态方面是有用的。

We have been making an effort to create rat brain hemoglobin oxygen saturation image by using two wave length of near infra-red light (NIR), which gives only the ratio such as oxygen saturation. This study employed three wave length of NIR,and obtained total hemoglobin and its saturation images. In first year, we applied this method to a hypoxic brain model to evaluate usefulness of this method, and successively obtained an increase of deoxy hemoglobin and decrease of oxyhemoglobin at lower limit of FIO_2 (7.5% O_2). Second year, we applied this method to an infraction model of rat brain, and obtained hemoglobin images which clearly showed the infarcted legion. These results suggest an usefulness of the optical imaging method to detect oxygenation state of brain non invasively.