Laser speckle contrast imaging of Raynaud phenomenon.

483 peripheral microcirculatory blood flow on a large area of the body.1 LSCI is user‐friendly and shows very good reproducibility as well as excellent spa‐ tial and temporal resolutions.2 In clinical studies, LSCI coupled with reactivity tests enable to esti‐ mate the endothelial and neurovascular function. We present the measurements of skin per‐ fusion assessed by LSCI in patients with pri‐ mary and secondary Raynaud phenomenon. FIGURE 1 shows skin flux derived from speckle con‐ trast analysis with colors ranging from blue (no perfusion) to red (high perfusion). LSCI provides a perfusion index proportional to skin blood flow and allows to record up to 100 images per sec‐ ond. FIGURE 1A presents a clear lack of perfusion in the index finger in a patient with primary Rayn‐ aud phenomenon. FIGURE 1B presents the hand of a patient with scleroderma. We can see ulcers in Raynaud phenomenon is an episodic vasospasm of the peripheral microvessels in response to cold or stress. It can be primary, or less frequently sec‐ ondary, to a systemic disease, the most frequent being scleroderma. The pathophysiology is most likely related to abnormal digital microvascular sensitivity to sympathetic stimulation that may also involve an abnormal response of the endo‐ thelium. Owing to its small size and regional het‐ erogeneity, studies of the skin microcirculation remain challenging and the only routine meth‐ od is videocapillaroscopy for evaluating microvas‐ cular structure. In addition, skin microvascular dysfunction has been described in many cardio‐ vascular disorders. Laser speckle contrast imaging (LSCI) is a re‐ cently developed technique that allows nonin‐ vasive, noncontact, and real‐time monitoring of