Hyperspectral imaging of bruises

Abstract

Introduction Hyperspectral imaging combines a camera with a tunable optical filter to record reflectance spectrophotometry data over a range of wavelengths for each image point. The data can be mathematically processed. Bruises comprise extravasated blood (haemoglobin) in the skin that is broken down to haemosiderin and bilirubin, the presence of which can be demonstrated by analysis of hyperspectral data. Aims To develop hyperspectral image data processing to demonstrate the spatial distribution of bruises and their temporal changes. Method Bruise-type injuries were created by injection of blood into skin of rats (with Animal Ethics Approval 1 ). Hyperspectral images were captured using a Chemimage HSI examiner 100 QD at a range of time points. Hyperspectral data were processed to analyse the first derivative to quantify the accumulation of degradation products of haemoglobin; tissue was also examined histologically. Results Hyperspectral images were successfully obtained; however, initial processing did not provide a defined correlation with time or histological changes. Discussion Initial results using simple analysis of first derivative values did not produce a clear correlation with accumulation of haemoglobin degradation products over time. Advanced processing techniques will be tested and the outcome of these will be presented.