Validation of ultraviolet, infrared, and narrow band light alternate light sources for detection of bruises in a pigskin model

Alternate light sources such as ultraviolet, narrow band, and infrared have been used in an attempt to reveal the presence of bruising that is not otherwise apparent (inapparent). The following study evaluates the ability of alternate light sources to enhance visibility of bruises by employing an objective assessment of digital photography images in conjunction with histology. A pigskin model was employed with bruises created by injection of blood to be not visible or barely visible (inapparent) under white light. The pigskin was photographed using alternate light source illumination. Images were assessed using the program Fiji^® to measure enhancement in terms of bruise length (cm). Photography results were compared with histology to confirm the presence of bruising. Violet and blue light sources produced the greatest enhancement, both with a p < 0.0001. Regions that were not bruises were also enhanced with light sources in this study, indicating that light sources are not specific, and that their use to enhance the visibility of bruising should be undertaken with caution.