Measurement of cochlear blood flow by direct visualization technique : comparison with laser Doppler method

1994年，作者在不使用任何染料或荧光的情况下，用图像分析程序直接观察耳蜗血管纹内的血流。为了观察血管纹内的血流，小心地去除耳蜗第二回的骨壁。通过Olympus显微镜（SZ 6045，TRPT）直接暴露并观察膜迷路。这种血流的直接可视化技术相当困难，但锻炼使研究人员在3只豚鼠中有2只成功。图像分析是可能的，但如果手术曝光和直接观察不是在同样稳定的条件下进行，则不可靠，因此，1996年尝试了染料和荧光使图像清晰。但这些技术不能产生更可靠的图像分析，其结果与不加染料和荧光的直接显示法相同，因此，我们将不加染料和荧光的直接显示法与激光多普勒法的结果进行了比较，在直接显示法中，只有大量的肾上腺素引起耳蜗血流的显著变化，同时激光多普勒法可使少量肾上腺素引起耳蜗血流明显改变。结果表明，激光多普勒技术比直接可视化技术更敏感。然而，直接可视化技术提供了对血流的全面观察，如果通过某些方法充分增强血流中红细胞的对比度，则它将是一种有用的技术。

Derect visualization of blood flow in stria vascularis of the cochlea was investigated without any dye or fluorescence by means of image analysis program in 1994. To observe the blood flow in the stria vascularis, the bony wall on the second turn of the cochlea was removed carefully. The membranous labyrinth was exposed and visualized directly by Olympus microscope (SZ 6045, TRPT). This direct visualization technique of blood flow was fairly difficult, but exercise allowed the investigators to have a success in 2 out of 3 guinea pigs. The image analysis was possible, however, it was unreliable, if the surgical exposure and direct visualization were not performed under samely stable conditions.Thus, dye and fluorescence was tried to make the image clear in 1996. However, those technique did not produce more reliable image analysis, and the result was as same as that of the direct visualization without dye and fluprescence.Therefore, we compared the result obtasined by direct visualization without dye and fluorescence with that obtained by laser Doppler method.In direct visualization technique, only a large amount of adrenalin induced a significant change of cochlear blood flow, meanwhile laser Doppler method induce significant changes in cochlear blood flow by less amount of adrenalin. Our result suggests that laser Doppler technique is more sensitive than direct visualization technique. However, direct visualization technique offers the total observation of blood flow, and then it would be a useful technique if the contrast of erythrocytes in the blood flow is sufficiently enhanced by some methods.