Use of Plain-white Paper Sticker as Novel Marker/Pointer for Infrared Imaging of Skin Lesions.

Clinical Challenge While taking images of skin lesions from an infrared camera, a commonly encountered problem is the difficulty of targeting a point of interest on the skin through the camera and matching it with the clinical image of the lesion. Thus, the need for an easy, thermo-neutral marker or pointer that can show up recognizably on the thermal image was felt. Solution The skin lesion of interest is recognized and demarcated using a plain-white paper sticker, which can be cut out in the form of an arrow or any desired shape. The thickness of the arrow is kept to a minimum, but wide enough so that the shape outline can be made out clearly from a distance of around 20 centimeters. The sticker is left in place for some time for the temperature of the skin (underneath the sticker) to reach equilibrium with the surrounding skin [Figure 1]. The infrared camera is held at a distance of 20 centimeters from the patient’s skin and directed perpendicular to it. Figure 2 depicts how the image is supposed to appear on the thermogram with the outline of the arrow-sticker clearly demarking the area of interest on the skin, without interfering with the thermal signature of the actual lesion. Following these steps also negates the use of a skin marker pen, which can alter the natural thermal emission of the skin (pressure applied on skin, evaporative cooling of skin from the ink) – issues that can be solved using our method.Figure 1: Application of an arrow-shaped sticker cutout on the site of interest on the skinFigure 2: Infrared thermogram, as captured through the infrared camera, with the outline of the arrow cutout clearly visibleLimitation We should not measure directly on the pointer area. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest. Use of artificial intelligence (AI) The preparation of this manuscript was carried out entirely by the authors without the use of artificial intelligence technologies.