Abstract
Laser speckle flowgraphy（LSFG）quantifies and visualizes blood flow. With an 830nm laser, the depth of illumination of the surface of the skin is approximately 1mm. The laser is scattered by the red blood cells flowing in the tissue. This scattered light interferes with itself, resulting in a random speckled pattern. LSFG detects the scattered movement pattern as a measurement of blood flow velocity, with a measurement time of 4 seconds. The blood flow map is recorded as a 30 frame per second movie. Although this flowgraphy method provides quantifiable data, it also allows display of this information in the form of a colored map. Therefore, LSFG is a good tool for observation of quick changes in blood flow velocity, such as before and after revascularization. Clinical advantages include: 1) its painlessness; 2) its ability to visualize blood flow in two dimensions without contacting the skin; 3) its ease of use; and 4) its two-dimensional view of blood flow, which can be represented on the associated angiosomes, and of the blood supply from the three arteries, which can be viewed independently. Thus, obstructions of the main arteries can be easily located, and arterial sections free of flow obstruction can also be identified.
