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

Abstract

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.

Detection of Inflicted Bruises by Alternate Light: Results of a Randomized Controlled Trial

“…The few available studies have found use of an ALS enhanced bruise observation, but researchers were unable to control for the potential effects of false positives either through study design (21,24,25) or execution (23). Confounding factors, such as preexisting skin conditions and topical products, could mimic bruising by producing absorption under alternate light (21,26,27). Additionally, none of the research to date has examined how skin color impacts detection of bruising using an ALS.…”

A comparison of four different imaging modalities – Conventional, cross polarized, infra-red and ultra-violet in the assessment of childhood bruising

“…We chose to analyze four different descriptors in the computer aided bruise measurements, in comparison to previous studies that measured only the maximum dimensions of bruises in different image wavelengths. Olds et al (2016) 23 compared maximum Feret's diameter of bruises in a pigskin model on conventional, UV and IR images. Significant differences were found between the diameters on UV and conventional images; on IR images these Feret's diameters were not measurable.…”

“…The greatest contrast was noted with conventional, and cross polarized light, and reduced performance on darker skin. Quantitative comparisons of maximum diameters of bruises on images taken in alternate light sources including conventional, IR and UV in a pigskin model 23 and in non-embalmed and embalmed cadavers 24 have been carried out lately using Fiji 25 distribution of ImageJ software.…”

Optimising the measurement of bruises in children across conventional and cross polarized images using segmentation analysis techniques in Image J, Photoshop and circle diameter measurements

“…There have been efforts to define a standardised approach to medical imaging of bruises, 3 and to describing the optimal image capture, 20 defining the optimal approach to image analysis will enhance the ability of both practitioners and researchers to draw comparisons across different subjects and populations. Table 1 Spearman's rank correlation values with their 95% confidence intervals (CI) for 38 visible bruises, comparing in vivo manual measurement with electronic measuring techniques, for both conventional and cross polarized images.…”

“…17 As a quantitative descriptor of the segmented images, and therefore the bruises, the maximum Feret diameter was chosen. 18 This commonly used measure in image processing 19,20 was calculated by the software in units of pixels. In order to convert maximum Feret diameter into millimetres (mm), the metric ruler scale of ABFO in each image were measured in pixels, and the resolution of each image was established (as mm/pixel) and used for analysis (see Figure 1a).…”