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

1994年用图像分析程序研究了不含任何染料或荧光的耳蜗纹血流的直接显示。为观察血管纹内的血流情况，仔细切除第二转耳蜗骨的骨壁。膜迷路在奥林巴斯显微镜(SZ 6045，TRPT)上显露并直接显示。这种直接的血流可视化技术相当困难，但运动让研究人员在3只豚鼠中有2只获得了成功。然而，如果不在同样稳定的条件下进行手术曝光和直接可视化，图像分析是可能的，但它是不可靠的。因此，1996年尝试了染料和荧光来使图像清晰。然而，这些技术并没有产生更可靠的图像分析结果，其结果与不含染料和荧光的直接可视化的结果相同。因此，我们将不含染料和荧光的直接可视化的结果与激光多普勒法的结果进行了比较。在直接可视化技术中，只有大量的肾上腺素才能引起耳蜗血流量的显著变化，而激光多普勒法则是通过较少的肾上腺素引起耳蜗血流量的显著变化。我们的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红细胞在血流中的对比度，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.