In this manuscript, we describe for the first time a novel technique to diagnose radial artery occlusion.The Laser Doppler Scan is a promising non-invasive diagnostic technique that allow quick and easy diagnosis of RAO after catheterization in an operator-independent manner. It uses low-power laser beam, and generates color-coded maps of blood perfusion. This technique has several advantages over traditional diagnostic methods: a) blood flow is measured over a large area (the whole hand in this case) rather than at a single site, avoiding measurement bias due to site-to-site variability; b) it is quicker than the current standard of reference, represented by vascular Doppler; c) it is very simple to perform, thus operator independent; d) the measurement does not require any contact to the skin, avoiding potential influence on the underlying blood flow or mechanically induced artefacts