The perception of yellow in bruises

Welfare of broilers on farm

This Scientific Opinion considers the welfare of domestic fowl (Gallus gallus) related to the production of meat (broilers) and includes the keeping of day-old chicks, broiler breeders, and broiler chickens. Currently used husbandry systems in the EU are described. Overall, 19 highly relevant welfare consequences (WCs) were identified based on severity, duration and frequency of occurrence: 'bone lesions', 'cold stress', 'gastro-enteric disorders', 'group stress', 'handling stress', 'heat stress', 'isolation stress', 'inability to perform comfort behaviour', 'inability to perform exploratory or foraging behaviour', 'inability to avoid unwanted sexual behaviour', 'locomotory disorders', 'prolonged hunger', 'prolonged thirst', 'predation stress', 'restriction of movement', 'resting problems', 'sensory under- and overstimulation', 'soft tissue and integument damage' and 'umbilical disorders'. These WCs and their animal-based measures (ABMs) that can identify them are described in detail. A variety of hazards related to the different husbandry systems were identified as well as ABMs for assessing the different WCs. Measures to prevent or correct the hazards and/or mitigate each of the WCs are listed. Recommendations are provided on quantitative or qualitative criteria to answer specific questions on the welfare of broilers and related to genetic selection, temperature, feed and water restriction, use of cages, light, air quality and mutilations in breeders such as beak trimming, de-toeing and comb dubbing. In addition, minimal requirements (e.g. stocking density, group size, nests, provision of litter, perches and platforms, drinkers and feeders, of covered veranda and outdoor range) for an enclosure for keeping broiler chickens (fast-growing, slower-growing and broiler breeders) are recommended. Finally, 'total mortality', 'wounds', 'carcass condemnation' and 'footpad dermatitis' are proposed as indicators for monitoring at slaughter the welfare of broilers on-farm.

Determination of the age of bruises using a bilirubinometer

The dating of bruises can be of crucial interest in clinical forensic medicine, but the macroscopic or photographic evaluation of a bruise has not been regarded as reliable. Several methods have thus been regularly evaluated for this purpose, with reflectance spectrometry yielding promising results. The objective of this study is to evaluate the value of a bilirubinometer as a tool for dating bruises on living victims. A clinical follow-up was carried out on patients presenting a bruise with a known onset. Using a bilirubinometer, we obtained daily measurements of the bruise (bili-bruise) and of healthy skin (bili-skin). Potential confounding factors were collected: age, sex, body mass index, trauma mechanism and Fitzpatrick skin phototype. We followed 20 patients for a total of 88 measurements of bruises. Bili-skin values showed significant differences according to skin phototype. Differences between the bili-bruise and bili-skin values (Δ-bili) followed an increase phase, peaking between 3 and 5 days, and then there was a decrease phase. No significant Δ-bili value differences were observed based on the suspected confounding factors. Our results are in favour of a peak Δ-bili value generally at day 4 or 5 post-trauma. Notably, decreasing values were not observed before day 3. Decreasing Δ-bili values would then indicate a bruise resulting from an injury formed at least 3 days before the first measurement. Complementary work confirming such data would enable improvement of the performance of bruise dating in forensic medicine.

Visualization of old bruises in children: Use of violet light to record long-term bruises

When a child consultation center evaluates abused children, evidence of the abuse must be documented. Children who have suffered physical abuse often have bruises, which cannot be confirmed by visualization when the bruise has healed. In forensics, a method to confirm an old bruise by ultraviolet radiation is possible. However, long-term ultraviolet exposure can be harmful. In this study, we observed 15 bruises on healthy volunteer children using four kinds of light sources, including ultraviolet radiation, over time. The violet light source enabled observation of a bruise for a longer time than ultraviolet radiation. Although other studies have shown that violet light is superior for enhancing bruises, this is the first report to evaluate data concerning the ability to identify bruises over time in living children. These results might help to identify evidence of past violence suffered by children.

Reliability of tristimulus colourimetry in the assessment of cutaneous bruise colour

BACKGROUND

Bruising is one of the most common types of injury clinicians observe among victims of violence and other trauma patients. However, research has shown commonly used qualitative description of cutaneous bruise colour via the naked eye is subjective and unreliable. No published work has formally evaluated the reliability of tristimulus colourimetry as an alternative for assessing bruise colour, despite its clinical and research applications in accurately assessing skin colour. The purpose of this study was to systematically evaluate the test-retest and inter-observer reliability of tristimulus colourimetry in the assessment of cutaneous bruise colour.

METHODS

Two researchers obtained repeated tristimulus colourimetry measures of cutaneous bruises with participants of diverse skin colour. Measures were obtained using the Minolta CR-400 Chomameter. Commission Internationale d'Eclairage (CIE) L*a*b* colour space was used. Data was analysed using intraclass correlation coefficients (ICC), Cronbach's alpha, and minimal detectable change (MDC) on all three L*a*b* values.

RESULTS

The colorimeter demonstrated excellent test-retest or intra-rater reliability (L* ICC=0.999; a* ICC=0.973; b* ICC=0.892) and inter-rater reliability (L* ICC=0.997; a* ICC=0.976; b* ICC=0.982).

CONCLUSIONS

With consistent placement, the tristimulus colourimetry is reliable for the objective assessment and documentation of cutaneous bruise colour for purposes of clinical practice and research. Recommendations for use in practice/research are provided.

Heme oxygenase-1 and heme oxygenase-2 expression in bruises

The first step in catabolism of hemoglobin in a bruise is performed by the enzyme heme oxygenase, which produces biliverdin that is then reduced to bilirubin. The development of yellow coloration in bruises can be attributed to local accumulation of degradation products of hemoglobin, including bilirubin, but it is not clear why there is a delay before this color change is apparent. One explanation may be that time is required for the establishment of heme oxygenase activity at the bruise site. This study used immunohistochemistry to examine the time course of expression of heme oxygenase-1 and heme oxygenase-2 in a rat bruise model. Heme oxygenase-1 levels rose above background from 6 h to peak from days 1 to 3. There was strong expression by macrophages, but only occasional neutrophils expression of heme oxygenase-1. Heme oxygenase-2 did not change significantly from background levels. The results suggest that the delay in the development of yellow coloration of bruises may in part be attributed to the requirement for macrophages to be recruited to the site of injury.

Age determination of soft tissue hematomas

In clinical forensic medicine, the estimation of the age of injuries such as externally visible subcutaneous hematomas is important for the reconstruction of violent events, particularly to include or exclude potential suspects. Since the estimation of the time of origin based on external inspection is unreliable, the aim of this study was to use contrast in MRI to develop an easy-to-use model for hematoma age estimation. In a longitudinal study, artificially created subcutaneous hematomas were repetitively imaged using MRI over a period of two weeks. The hemorrhages were created by injecting autologous blood into the subcutaneous tissue of the thigh in 20 healthy volunteers. For MRI, standard commercially available sequences, namely proton-density-weighted, T2 -weighted and inversion recovery sequences, were used. The hematomas' MRI data were analyzed regarding their contrast behavior using the most suitable sequences to derive a model allowing an objective estimation of the age of soft tissue hematomas. The Michelson contrast between hematoma and muscle in the proton-density-weighted sequence showed an exponentially decreasing behavior with a dynamic range of 0.6 and a maximum standard deviation of 0.1. The contrast of the inversion recovery sequences showed increasing characteristics and was hypointense for TI = 200ms and hyperintense for TI =1000ms. These sequences were used to create a contrast model. The cross-validation of the model finally yielded limits of agreement for hematoma age determination (corresponding to ±1.96 SD) of ±38.7h during the first three days and ±54 h for the entire investigation period. The developed model provides lookup tables which allow for the estimation of a hematoma's age given a single contrast measurement applicable by a radiologist or a forensic physician. This is a first step towards an accurate and objective dating method for subcutaneous hematomas, which will be particularly useful in child abuse.

The use of photographs to record variation in bruising response in humans

There is considerable value in developing tools capable of accurately and reliably determining when bruises were inflicted in humans. Previous work has focused on the visual changes observed in a bruise as the injury develops and heals. However, due to variables such as how and where on the body the bruise was inflicted, differing tissue compositions at the injured skin site between individuals and inter- and intra-observer variation; a technique sufficiently robust for use in a clinical or medicolegal setting has not yet been identified. In this study we present a series of photographs taken under controlled conditions illustrating standardised bruises induced on participants using a weight dropping mechanism. We show that variation in the appearance of bruises over time across individuals is large and, although photography may be a suitable technique for the recording of injuries, it is not sufficiently reliable for determining the age of a bruise.

The effect of image quality on the assessment of child abuse photographs

OBJECTIVES

Although child abuse pediatricians are frequently asked to evaluate risk of abuse based on photographs, the effect of photographic quality on this process is presently unknown. Photographs of abused children are often taken by professionals without photographic training, and quality varies widely. This article reports the first study of the effect of image quality on clinical assessment from photographs.

METHODS

A total of 120 images depicting 60 cutaneous lesions were selected for the study. Paired images of single lesions varied in quality of focus, exposure, or framing. Seventy medical and nursing professionals were recruited from the Internet listservs focusing on child abuse. Subjects evaluated the images for quality (1-9 scale), opined if the image was "inadequate for interpretation," and answered a clinical question about the type of lesion displayed. Accuracy was defined as concordance between the subject and the live examiner's written documentation. Adequacy was defined as the proportion of subjects that did not indicate that the photograph was inadequate for interpretation.

RESULTS

Mean accuracy among subjects was 64% and ranged from 35% to 84%. Accuracy was not predicted by subject profession, experience, or self-rated computer skill. Image quality and adequacy were independently associated with increased accuracy.

CONCLUSIONS

Higher-quality images improved accuracy. An examiner's impression that an image is adequate did not guarantee an accurate interpretation. Reliance on photographs alone is not sufficiently accurate in the assessment of cutaneous trauma.

The development of a colorimetric scale as a visual aid for the bruise age determination of bite marks and blunt trauma

Medical examiners and forensic odontologists are frequently asked to establish the age of a bruise or bitemark on either a living and deceased subjects. The age of bruising has an important medico-legal significance and may be relevant in the investigations related to such crimes as child abuse, domestic violence and homicide. A colorimetric scale for forensic photography based on the colors of the bruise itself, has never been proposed due to the fact that photographic reproduction of color is unreliable and depends on several factors; the camera used, lighting, printer and photo-editing color calibration. The authors propose two colorimetric scales, both with and without linear measurements, and with 90° angulations, six bruise colors, and three circles with black and white calibrators, which are to be used for the forensic photography of injuries involving the epidermis of Caucasian subjects. The two scales could also be employed on living subjects during different stages of the healing process, or on cadavers in order to provide evidential documentation, image verification and analysis. Such an aid would provide a reliable standard condition and allow for color calibration. The colors represented on the scales would be an aid for the interpretation and objectivity required in estimating the age of the bruise, particularly when the analysis is made directly onto computer images prior to printing. The proposed colorimetric scales do not attempt to give a definitive account of the diverse scientific methods available for the assessment of the age of bruising. The observation of a large sample of blunt trauma and bite mark injuries employing the proposed colorimetric scales would be needed in order to verify and validate the use of these scales. It should be borne in mind that bruise age estimation requires an expert opinion with several degrees of accuracy and variability involved. The age of a bruise cannot be determined by color alone.

How the blood pool properties at onset affect the temporal behavior of simulated bruises

The influence of initial blood pool properties on the temporal behavior of bruises is currently unknown. We addressed this important issue by utilizing three typical classes of bruises in our three-layered finite compartment model. We simulated the effects of their initial shapes, regularity of boundaries and initial blood concentration distributions (gaussian vs. homogeneous) on the hemoglobin and bilirubin areas in the dermal top layer. Age determination of bruises with gaussian hemoglobin concentration was also addressed. We found that the initial blood pool properties strongly affect bruise behavior. We determined the age of a 200-h simulated bruise with gaussian hemoglobin concentration with 3 h uncertainty. In conclusion, bruise behavior depends non-intuitively on the initial blood pool properties; hence, a model that includes shape, area and concentration distribution at onset is indispensable. Future age determination, including inhomogeneous hemoglobin distributions, will likely be based on the presented method for gaussian distributions.

Assessment of bruise age on dark-skinned individuals using tristimulus colorimetry

INTRODUCTION

Studies on the ageing of bruises have been reported on Caucasians or individuals of fair ethnicity. This study focuses on bruise changes in dark-skinned individuals using tristimulus colorimetry for forensic analysis in such individuals.

METHODS

Eighteen subjects of South Indian or Sri-Lankan ethnicity were recruited. Subjects were bruised using a vacuum pump and then daily colour measurements were taken of the bruise using a tristimulus colorimeter. The L*a*b* readings were recorded of a control area and of the bruise until it disappeared. Two Caucasians were used for comparison.

RESULTS

This study showed that, using colorimetry, bruises on dark-skinned individuals can be measured and analysed even if the bruises are unclear visually. As the bruise is beneath the skin, the colour difference ΔL*, Δa* and Δb* were calculated. All values showed a trend, indicating that the L*a*b* measuring technique is a reliable method to analyse bruises on dark-skinned individuals. Comparisons of Asian subjects and Caucasian subjects were performed. The largest difference was seen in the b* value. Statistical analysis showed that ΔL* colour difference was the most consistent (95% CI -4.05 to -2.49) showing a significant difference between days 1-4 and 5-8.

CONCLUSION

Objective assessment of bruises on dark-skinned individuals using the L*a*b* method of measuring gave reproducible results. Furthermore, the study showed that the yellowing of a bruise cannot be seen or measured with a tristimulus colorimeter on dark-skinned individuals due to the pigmentation of the skin. With further studies and more subjects, the age of bruises could potentially be assessed for use in forensic analysis.

Can color inhomogeneity of bruises be used to establish their age?

Bruises become spatially inhomogeneous during the healing process; a smaller red-blue core area, caused by hemoglobin, is surrounded by a larger yellow area, caused by bilirubin, which is enzymatically formed from hemoglobin. These two areas develop at different rates and hence carry information about the age of the bruise. We present a proof of principle demonstration that the age of bruises can be determined via an inverse procedure using a mathematical model and daily measurements of these two areas using a hyperspectral imaging system. The inaccuracy found is 2.3% for fresh bruises and 3 to 24% for bruises up to 3 days old. In conclusion, color inhomogeneity of bruises can be used to determine their age. We expect that future age determination of bruises by the inverse procedure described here, possibly also including the distribution of concentrations in the areas will open up a new phase in clinical bruise classification.

Can we assess the age of bruises? An attempt to develop an objective technique

AIMS

The aims of this study were (A) to investigate whether the number of years of forensic experience affected the accuracy with which forensic experts (FEs) were able to age bruises and (B) to identify the properties and colours of a bruise that were utilized by FEs in their assessment of bruise age. The study then investigated the possibility of using a more objective technique. It was decided to use readily available digital photography and software to objectively assess changes in bruise colouration and to investigate if this can be used to age bruises.

METHODS

Twenty-three FEs were shown 25 photographs of bruises of varying but known ages and asked to estimate the ages. In part two of the study, bruises were inflicted on volunteers using a vacuum pump and photographs taken of the bruise daily from infliction to resolution. The images were analysed using Adobe Photoshop. Red, green and blue (RGB) values were recorded for each bruise and analyses carried out comparing the values over time between subjects and within subjects.

RESULTS

This study both enhanced and supported a previous conclusion that visual assessment of photographs is an unreliable method for ageing bruises. Additionally, it found that the degree of forensic experience had no effect on accuracy. It also identified that colour (particularly yellow, red and purple) and intensity of colour were the most commonly used properties of a bruise in the assessment of its age. The RGB method proved to be a reliable technique with which to measure bruise colour, but its validity in the assessment of bruise age was poor.

CONCLUSIONS

Visual assessment of bruises is unreliable and the accuracy of ageing was not improved by the degree of forensic experience. The RGB method gave highly reproducible results, but did not accurately assess bruise age. However, results within subjects suggested that there may be individual variation in haemoglobin metabolism.

Use of reflectance spectrophotometry and colorimetry in a general linear model for the determination of the age of bruises

Bruises can have medicolegal significance such that the age of a bruise may be an important issue. This study sought to determine if colorimetry or reflectance spectrophotometry could be employed to objectively estimate the age of bruises. Based on a previously described method, reflectance spectrophotometric scans were obtained from bruises using a Cary 100 Bio spectrophotometer fitted with a fibre-optic reflectance probe. Measurements were taken from the bruise and a control area. Software was used to calculate the first derivative at 490 and 480 nm; the proportion of oxygenated hemoglobin was calculated using an isobestic point method and a software application converted the scan data into colorimetry data. In addition, data on factors that might be associated with the determination of the age of a bruise: subject age, subject sex, degree of trauma, bruise size, skin color, body build, and depth of bruise were recorded. From 147 subjects, 233 reflectance spectrophotometry scans were obtained for analysis. The age of the bruises ranged from 0.5 to 231.5 h. A General Linear Model analysis method was used. This revealed that colorimetric measurement of the yellowness of a bruise accounted for 13% of the bruise age. By incorporation of the other recorded data (as above), yellowness could predict up to 32% of the age of a bruise-implying that 68% of the variation was dependent on other factors. However, critical appraisal of the model revealed that the colorimetry method of determining the age of a bruise was affected by skin tone and required a measure of the proportion of oxygenated hemoglobin, which is obtained by spectrophotometric methods. Using spectrophotometry, the first derivative at 490 nm alone accounted for 18% of the bruise age estimate. When additional factors (subject sex, bruise depth and oxygenation of hemoglobin) were included in the General Linear Model this increased to 31%-implying that 69% of the variation was dependent on other factors. This indicates that spectrophotometry would be of more use that colorimetry for assessing the age of bruises, but the spectrophotometric method used needs to be refined to provide useful data regarding the estimated age of a bruise. Such refinements might include the use of multiple readings or utilizing a comprehensive mathematical model of the optics of skin.

Visual assessment of the timing of bruising by forensic experts

INTRODUCTION

Forensic experts are frequently asked to comment on the age of injuries and interpretation may have significant medico-legal consequences. The purpose of this study is to determine the accuracy with which forensic experts can visually age a bruise from photographs produced under standard conditions.

METHODS

Bruises were produced on the upper arms of 11 subjects by a suction pump. Sequential photographs were taken daily until they were no longer visible to the naked eye. Fifteen forensic experts who did not know the age of the bruises were asked to estimate their ages and also to place them in chronological order.

RESULTS

Hundred and thirty-two images of 25 bruises were produced, ranging from 0 to 209h in age. There was considerable inter- and intra-observer variability in accuracy (median difference between the estimated age and the real age=26.0h (95% C.I. 24.0-31.0h). There was greatest accuracy for bruises photographed between 0 and 12h. No significant differences were seen between male and female observers (p=0.553) and performance was also unaffected by the age of the observer (p=0.160). Of the bruise images placed in chronological order >80% of the observers made between 0 and 2 errors.

CONCLUSION

Bruise age estimates by forensic experts, from photographs, are unreliable. However, it appears that the vast majority of observers are better able to place bruises from the same subjects in their chronological order.

Can one accurately date a bruise? State of the science

Forensic nursing experts and other health professionals often testify regarding the injuries women and men receive from violence. Bruise discoloration can provide an opportunity for health professionals to grossly estimate the age of impact and determine if it is consistent with a given reported history. However, there is much confusion in the literature and clinical practice as to the accuracy of dating bruises. This article will demonstrate that using the color of the bruise as the primary criteria to determine its age is not the best practice. The limited available research and related literature on the topic are flawed and inconsistent. Finally, recommendations will be made for future research and clinical practice.

A novel approach to age determination of traumatic injuries by reflectance spectroscopy

BACKGROUND AND OBJECTIVES

Aging of injuries on a victim's body is an important aspect of forensic medicine. Currently, visual assessment and colorimetry based on empirical criteria are the most common techniques for this task, although the results are uncertain. A trauma causing localized vessel damage will rapidly result in a pool of blood in subcutaneous tissues. The color of the bruise is, however, primarily due to hemoglobin transport into dermis and secondarily to its breakdown products. This transport is analyzed in terms of hemoglobin diffusion followed by clearance by macrophage activity, lymphatic flow, and conversion to breakdown products such as bilirubin. The color of a bruise is caused by hemoglobin and hemoglobin breakdown products. The color will change with time, and such color changes can be recorded using reflectance spectroscopy. The aim of this study was to develop a mathematical model to describe blood diffusion within bruised skin, and to use this method to retrieve the age of a bruise from measured skin reflectance.

STUDY DESIGN/MATERIALS AND METHODS

An analytic model was established to describe the development and fading of bruise color. The model, which is based on Darcy's law of convection flow and Fick's law of diffusion, describes the distribution of blood and hemoglobin breakdown products within a hematoma as a function of time after injury. The initial phase after injury is described by a convective extravascular blood flow in subcutaneous tissues, and further development of the bruise is described by diffusion and breakdown of whole erythrocytes and hemoglobin in dermis. Experimental data were used to verify the model. Reflection spectra in the 400-850 nm wavelength range were collected from normal and bruised skin using an integrating sphere setup. The subjects were adult patients admitted to the Department of cardiothoracic surgery, St. Olav's Hospital, Trondheim, Norway. The skin hematomas were caused by external trauma, cardiothoracic examinations, or surgery.

RESULTS

Preliminary results show that measured and simulated skin reflectance agrees well. The model predicts the age of a hematoma with an accuracy of approximately 1 day. The accuracy of the method depends on precise information of skin thickness in the injured area. The quality of the estimates from the model will thus be enhanced if a reliable measure of skin thickness is collected concurrently with the reflection measurement.

CONCLUSIONS

The time development of a skin hematoma is described with good accuracy by the implemented model. The analytic method provides a theoretical basis for developing an apparatus to determine the age of injuries in forensic medicine.

Qualitative visual image analysis of bruise age determination: a survey

The evaluation of bruise color imaging is a very important task in forensic medicine. However, there is no standardized methodology in carrying out this task. In this paper, an attempt was made to review the different papers published in the literature on the visual assessment of bruise age determination, and derive color charts of daily bruise aging. Based on the color charts derived, the following observations can be made: (i) the bruise is red for day 1, (ii) there is no dominant color for day 2, whereas for day 3, blue is becoming slightly dominant, (iii) green is becoming dominant for days 4-6, with yellow color emerging, (iv) for day 7, there is coexistence of green and yellow, (v) yellow is highly dominant for days 7 to 14, with brown emerging. These charts can serve as guidelines for the qualitative evaluation of bruise imaging by visual analysis. Clearly, the need exists for the quantitative analysis of bruise color imaging.

Alternative light source (polilight) illumination with digital image analysis does not assist in determining the age of bruises

The age of a bruise may be of interest to forensic investigators. Previous research has demonstrated that an alternative light source may assist in the visualisation of faint or non-visible bruises. This project aimed to determine if an alternative light source could be utilised to assist investigators estimate the age of a bruise. Forty braises, sustained from blunt force trauma, were examined from 30 healthy subjects. The age of the bruises ranged from 2 to 231 h (mean = 74.6, median = 69.0). Alternative light source (polilight) illumination at 415 and 450 nm was used. The black and white photographs obtained were assessed using densitometry. A statistical analysis indicated that there was no correlation between time and the mean densitometry values. The alternative light source used in this study was unable to assist in determining the age of a bruise.