Fig. 4. Comparison of conventional LSCI and TR-LSCI for blood flow mapping in ear, hindlimb, back and paw of mice.

a Illustration of the system used for LSCI for ear, hindlimb, back and paw of mice. b Typical blood flow maps of cutaneous/subcutaneous vessels imaged by conventional LSCI and TR-LSCI. The white arrow heads indicate opposite dorsal subcutaneous blood vessels, and the white arrows indicate the blood vessels between tendons and metatarsals in the paw. c Line plots of dashed lines in (b). Black arrows indicate the position of vessels, and the crosses indicate the unidentifiable blood flow. d H&E staining of ear, skin on hindlimb, back and paw for measuring tissue thickness above the blood vessels. Red arrows indicate blood vessels containing red blood cells in ear and dorsal skin. The imaged blood vessels in mice hindlimb and paw were under the skin. The marked length is the thickness of skin tissue after H&E staining, which does not represent the real situation in vivo, and is only used to reflect the relative thickness of skin tissue in different body parts