Fig. 3
Representative examples of algorithmically generated space–time diagrams and corresponding detection of individual RBC paths before and after frame-by-frame image enhancement. Top row (a–d) represent algorithmically generated space–time diagrams; in the bottom row (a–d) individual RBC path detection is shown. Top left images (a–d) represent space–time diagrams produced without further image processing and demonstrate artifacts introduced by inter-frame variability in brightness (“flickering”) that translate into individual RBC path detection artifacts (bottom row, a–d). Results of frame-by-frame image enhancement are shown on top right (a–d), demonstrating marked reduction in individual RBC path detection artifacts (bottom row, a–d). Representative examples are given for capillaries with normal flow (individual vessel MFI = 3, a); “hyperdynamic” flow (b), demonstrating reliable detection of RBC velocity even when approaching vmax; intermittent flow (individual vessel MFI = 1, c); and no flow (“barcode sign”, individual vessel MFI = 0, d)
