Automatic Measurement of Lymphocyte Velocity by High-Speed Video Image Analysis

Abstract

In order to investigate the mechanisms of lymph flow, an algorithm has been newly developed for image processing and velocity measurement. The lymph flow of collecting lymphatics in the rat mesentery has been recorded as video images through an inverted intravital microscope. The lymph flow was rapid and its flow mode so complicated that the combination of a high-speed video cassette recorder and an image processing system was necessary. The image processing was carried out following the procedures of smoothing, median filtering with edge enhancement, lymphocyte extraction, automatic setting of the predicted flow area, and velocity measurement. Using this system, it was demonstrated that the maximum velocity of lymphocytes was 2—3 mm/s and that the velocity fluctuated forward and also backward. The results showed that our method of velocity measurement is more accurate than previous methods and that it had some other characteristics beneficial for further understanding of the lymphatic system.