High-speed CCD intravital microscope-visualization of subendocardial arteriolar blood velocity

To visualize the subendocardial arteriolar blood velocity, the authors developed a high-speed CCD microscope. The vascular images focused on the special CCD through a needle-probe were stored on a digital memory every 5 ms (200 images/s). The size of the visual field is 1/spl times/0.8 mm/sup 2/, and the spatial resolution is less than 4 /spl mu/m. The blood flow velocities in the microvessels were visualized by optically shinning microspheres (MS). MS (5-15 /spl mu/m /spl phi/) were prepared by polymerization of styrene monomer in which fine particles of heavy elements (0.2 /spl mu/m/spl phi/) were homogeneously distributed. Velocities of MS in the subendocardial arteriole were calculated by the distance of MS movement of 5 ms. The blood velocity waveforms in the microvessels were successfully obtained by the high-speed system. In conclusion, a newly developed microscope system was found to be a powerful tool for observation of dynamic blood velocity with diameter change in subendocardial microvessels in a beating dog heart.