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Relevance of Whitnall's tubercle and auditory meatus in diagnosing exclusions during skull-photo superimposition

Jayaprakash PT, Hashim N, Yusop RA

Forensic Sci Int, 2015 Aug;253:131.e1-10.
PMID: 26103927 DOI: 10.1016/j.forsciint.2015.04.026

Video vision mixer based skull-photo superimposition is a popular method for identifying skulls retrieved from unidentified human remains. A report on the reliability of the superimposition method suggested increased failure rates of 17.3 to 32% to exclude and 15 to 20% to include skulls while using related and unrelated face photographs. Such raise in failures prompted an analysis of the methods employed for the research. The protocols adopted for assessing the reliability are seen to vary from those suggested by the practitioners in the field. The former include overlaying the skull- and face-images on the basis of morphology by relying on anthropometric landmarks on the front plane of the face-images and evaluating the goodness of match depending on mix-mode images; the latter consist of orienting the skull considering landmarks on both the eye and ear planes of the face- and skull-images and evaluating the match utilizing images seen in wipe-mode in addition to those in mix-mode. Superimposition of a skull with face-images of five living individuals in two sets of experiments, one following the procedure described for the research on reliability and the other applying the methods suggested by the practitioners has shown that overlaying the images on the basis of morphology depending on the landmarks on the front plane alone and assessing the match in mix-mode fails to exclude the skull. However, orienting the skull relying on the relationship between the anatomical landmarks on the skull- and face-images such as Whitnall's tubercle and exocanthus in the front (eye) plane and the porion and tragus in the rear (ear) plane as well as assessing the match using wipe-mode images enables excluding that skull while superimposing with the same set of face-images.

Matched MeSH terms: Photography*
Photographing human subjects in biomedical disciplines: an Islamic perspective

Saidun S

J Med Ethics, 2013 Feb;39(2):84-8.
PMID: 23038799 DOI: 10.1136/medethics-2012-100794

Visual recording of human subjects is commonly used in biomedical disciplines for clinical, research, legal, academic and even personal purposes. Guidelines on practice standards of biomedical recording have been issued by certain health authorities, associations and journals, but none of the literature discusses this from an Islamic perspective. This article begins with a discussion on the general rules associated with visual recording in Islam, followed by modesty issues in biomedical recording and issues of informed consent and confidentiality. In order to be deemed ethical from the Islamic perspective, all the aforementioned criteria must conform to, or not contradict, Islamic teaching.

Matched MeSH terms: Photography/ethics*
On the integral use of foundational concepts in verifying validity during skull-photo superimposition

Jayaprakash PT

Forensic Sci Int, 2017 Sep;278:411.e1-411.e8.
PMID: 28754256 DOI: 10.1016/j.forsciint.2017.04.021

Often cited reliability test on video superimposition method integrated scaling face-images in relation to skull-images, tragus-auditory meatus relationship in addition to exocanthion-Whitnall's tubercle relationship when orientating the skull-image and wipe mode imaging in addition to mix mode imaging when obtaining skull-face image overlay and evaluating the goodness of match. However, a report that found higher false positive matches in computer assisted superimposition method transited from the above foundational concepts and relied on images of unspecified sizes that are lesser than 'life-size', frontal plane landmarks in the skull- and face- images alone for orientating the skull-image and mix images alone for evaluating the goodness of match. Recently, arguing the use of 'life-size' images as 'archaic', the authors who tested the reliability in the computer assisted superimposition method have denied any method transition. This article describes that the use of images of unspecified sizes at lesser than 'life-size' eliminates the only possibility to quantify parameters during superimposition which alone enables dynamic skull orientation when overlaying a skull-image with a face-image in an anatomically acceptable orientation. The dynamic skull orientation process mandatorily requires aligning the tragus in the 2D face-image with the auditory meatus in the 3D skull-image for anatomically orientating the skull-image in relation to the posture in the face-image, a step not mentioned by the authors describing the computer assisted superimposition method. Furthermore, mere reliance on mix type images during image overlay eliminates the possibility to assess the relationship between the leading edges of the skull- and face-image outlines as also specific area match among the corresponding craniofacial organs during superimposition. Indicating the possibility of increased false positive matches as a consequence of the above method transitions, the need for testing the reliability in the superimposition method adopting concepts that are considered safe is stressed.

Matched MeSH terms: Photography*
Fulltext Similarity measure and domain adaptation in multiple mixture model clustering: An application to image processing

Leong SH, Ong SH

PLoS One, 2017;12(7):e0180307.
PMID: 28686634 DOI: 10.1371/journal.pone.0180307

This paper considers three crucial issues in processing scaled down image, the representation of partial image, similarity measure and domain adaptation. Two Gaussian mixture model based algorithms are proposed to effectively preserve image details and avoids image degradation. Multiple partial images are clustered separately through Gaussian mixture model clustering with a scan and select procedure to enhance the inclusion of small image details. The local image features, represented by maximum likelihood estimates of the mixture components, are classified by using the modified Bayes factor (MBF) as a similarity measure. The detection of novel local features from MBF will suggest domain adaptation, which is changing the number of components of the Gaussian mixture model. The performance of the proposed algorithms are evaluated with simulated data and real images and it is shown to perform much better than existing Gaussian mixture model based algorithms in reproducing images with higher structural similarity index.

Matched MeSH terms: Photography/methods
Conceptual transitions in methods of skull-photo superimposition that impact the reliability of identification: a review

Jayaprakash PT

Forensic Sci Int, 2015 Jan;246:110-21.
PMID: 25498986 DOI: 10.1016/j.forsciint.2014.10.043

Establishing identification during skull-photo superimposition relies on correlating the salient morphological features of an unidentified skull with those of a face-image of a suspected dead individual using image overlay processes. Technical progression in the process of overlay has included the incorporation of video cameras, image-mixing devices and software that enables real-time vision-mixing. Conceptual transitions occur in the superimposition methods that involve 'life-size' images, that achieve orientation of the skull to the posture of the face in the photograph and that assess the extent of match. A recent report on the reliability of identification using the superimposition method adopted the currently prevalent methods and suggested an increased rate of failures when skulls were compared with related and unrelated face images. The reported reduction in the reliability of the superimposition method prompted a review of the transition in the concepts that are involved in skull-photo superimposition. The prevalent popular methods for visualizing the superimposed images at less than 'life-size', overlaying skull-face images by relying on the cranial and facial landmarks in the frontal plane when orienting the skull for matching and evaluating the match on a morphological basis by relying on mix-mode alone are the major departures in the methodology that may have reduced the identification reliability. The need to reassess the reliability of the method that incorporates the concepts which have been considered appropriate by the practitioners is stressed.

Matched MeSH terms: Photography
Malignant hypertension with papilledema

Tajunisah I, Patel DK

J Emerg Med, 2013 Jan;44(1):164-5.
PMID: 21820265 DOI: 10.1016/j.jemermed.2011.05.042
Matched MeSH terms: Photography
Novel risk index for the identification of age-related macular degeneration using radon transform and DWT features

Acharya UR, Mookiah MR, Koh JE, Tan JH, Noronha K, Bhandary SV, et al.

Comput Biol Med, 2016 06 01;73:131-40.
PMID: 27107676 DOI: 10.1016/j.compbiomed.2016.04.009

Age-related Macular Degeneration (AMD) affects the central vision of aged people. It can be diagnosed due to the presence of drusen, Geographic Atrophy (GA) and Choroidal Neovascularization (CNV) in the fundus images. It is labor intensive and time-consuming for the ophthalmologists to screen these images. An automated digital fundus photography based screening system can overcome these drawbacks. Such a safe, non-contact and cost-effective platform can be used as a screening system for dry AMD. In this paper, we are proposing a novel algorithm using Radon Transform (RT), Discrete Wavelet Transform (DWT) coupled with Locality Sensitive Discriminant Analysis (LSDA) for automated diagnosis of AMD. First the image is subjected to RT followed by DWT. The extracted features are subjected to dimension reduction using LSDA and ranked using t-test. The performance of various supervised classifiers namely Decision Tree (DT), Support Vector Machine (SVM), Probabilistic Neural Network (PNN) and k-Nearest Neighbor (k-NN) are compared to automatically discriminate to normal and AMD classes using ranked LSDA components. The proposed approach is evaluated using private and public datasets such as ARIA and STARE. The highest classification accuracy of 99.49%, 96.89% and 100% are reported for private, ARIA and STARE datasets. Also, AMD index is devised using two LSDA components to distinguish two classes accurately. Hence, this proposed system can be extended for mass AMD screening.

Matched MeSH terms: Photography
The effects of stereotyping on impression formation: cross-cultural perspectives on viewing religious persons

Chia EK, Jih CS

J Psychol, 1994 Sep;128(5):559-65.
PMID: 7983612

We examined the effects of stereotyping on impression formation when encountering people dressed to represent a religious faith. We used stimulus photographs of eight male and female models dressed casually and a second photograph of one male and one female model in religious attire that was placed beside the control photos of models dressed causally. From each set of photographs, subjects selected a photo of the person with whom they would associate the various positive personality traits suggested by our stimulus questions. Subjects were students from a U.S. Catholic school, a U.S. public school, and a Malaysian Muslim school. All the subjects attributed more of the positive traits to photos of the models who were religiously attired than to photos of those who were casually dressed, but subjects from U.S. schools attributed more of the positive traits to the photos of religiously dressed models than did the subjects from the Malaysian school.

Matched MeSH terms: Photography
Influence of WhatsApp and electronic mail reminders on oral hygiene compliance of orthodontic patients using planimetry : A randomized clinical trial

Saxena K, Gunjal S

J Orofac Orthop, 2021 May 04.
PMID: 33944974 DOI: 10.1007/s00056-021-00301-6

PURPOSE: To determine the effect of WhatsApp (Facebook Inc., Menlo Park, CA, USA) and electronic mail reminders on oral hygiene compliance of orthodontic patients.
METHODS: A randomized, parallel group, double blinded study was conducted on 54 patients undergoing orthodontic treatment at a university clinic. They were randomized to 3 groups, i.e., WhatsApp (W) group, electronic mail (email) (E) group and control (C) group with 18 subjects in each group. Group (W) and group (E) received oral health messages once a week through WhatsApp and email reminders, respectively, while group (C) did not receive any reminders. Plaque was measured at baseline (T0), after 4 weeks (T1), and after 8 weeks (T2). For each subject, intraoral photographs were taken after application of a plaque-disclosing agent; and the area covered by plaque was measured on teeth 12, 13, 43, 22, 23 and 33 by planimetry. Data were analyzed using SPSS (version 22, IBM Corp., Armonk, NY, USA). Mixed analysis of variance (ANOVA) was used to compare plaque scores between and within the groups.
RESULTS: A total of 54 subjects (14 males and 40 females) with mean age of 22.43 years completed the study. At the end of 8 weeks, no statistically significant difference in the mean plaque score was found between the groups at the different time intervals (p = 0.201).
CONCLUSION: WhatsApp and email reminders did not significantly influence the oral hygiene compliance of orthodontic patients.

Matched MeSH terms: Photography, Dental
Fulltext Prevalence of bimaxillary protrusion among UiTM orthodontic patients

Ruqoyyah Muslimat Othman, Noor Airin Aidil Koay, Sarah Haniza Abdul Ghani, Noraina Hafizan Norman

Compendium of Oral Science, 2019;6(1):1-8.
MyJurnal

Objective: To determine the prevalence of bimaxillary protrusion in general and the prevalence of skeletal Class I and dental Class I bimaxillary protrusion/ proclination among orthodontic patients attending postgraduate orthodontic clinic at Faculty of Dentistry, Universiti Teknologi MARA (UiTM), Sungai Buloh, Malaysia. Materials and Methods: This is a cross sectional study which was carried out in two stages. The first part involves a random selection of 100 extra-oral profile photographs taken from postgraduate orthodontic residents’ patient list. The photographs were taken using Canon digital SLR camera EOS 70D with macro lens EF 100mm (Canon Inc., Tokyo, Japan) with patients in natural head position. The photographs were visually analysed for its bimaxillary protrusion features by two operators. The second part comprises of analyses of extra-oral profile photographs as well as intra-oral photographs of right buccal segment view which was conducted in two separate sittings. In the first sitting, five assessors analysed 259 extra - and intra-oral photographs followed by 40 photographs assessed in the second sitting for skeletal and dental Class I bimaxillary protrusion/ proclination. Statistical analysis for Kappa score was performed to assess the agreement between assessors using SPSS version 23 and Stata version 13. Results: The first part of the study showed an average prevalence of 34% with bimaxillary protrusion in 100 orthodontic patients. Whilst in the second part, prevalence of skeletal and dental Class I bimax ranging from 28 -33 per cent and 38-40 per cent respectively with very good and good inter-reliability agreement for both component. Conclusion: The prevalence of bimaxillary protrusion in general among UiTM orthodontic patients was found to range from 31 per cent to 37 per cent. Whilst the prevalence of skeletal and dental Class I bimax ranging from 28-33 per cent and 38-40 per cent respectively.

Matched MeSH terms: Photography, Dental
Fulltext Stress and coping strategies among retired people in Malaysia: a qualitative study

Al-Naggar, Redhwan Ahmed, Chen, Robert

ASEAN Journal of Psychiatry, 2011;12(2):0-0.
MyJurnal

Objective: This study explored the stress and coping strategies among retired people in Malaysia. Methods: In-depth interviews were conducted with 36 elderly Malaysian subjects. This protocol was approved by the Ethics Committee of the Management and Science University. The data obtained were sorted into various categories. Results: A total number of 36 retired elderly people participated in this study. The majority of them were in the age group of 55-59 years old, females, Malay and married. The majority defined stress as pressure or tension. Financial difficulties, family and work problems were the main causes of stress in the majority. Also, the majority of respondents mentioned that they coped with stress by sharing problems with others, by resting and relaxing, and/or by doing housework during their free time. A few of them coped with stress by hanging out with friends, going shopping,
doing photography, travelling, going fishing, and doing sports. Conclusion: Financial difficulties, family and work problems were the main causes of stress among elderly people. They coped with stress by sharing problems with others, resting and relaxing, and/or doing housework during their free time.

Matched MeSH terms: Photography
Redness enhances perceived aggression, dominance and attractiveness in men's faces

Stephen ID, Oldham FH, Perrett DI, Barton RA

Evol Psychol, 2012 Aug 17;10(3):562-72.
PMID: 22947678

In a range of non-human primate, bird and fish species, the intensity of red coloration in males is associated with social dominance, testosterone levels and mate selection. In humans too, skin redness is associated with health, but it is not known whether--as in non-human species--it is also associated with dominance and links to attractiveness have not been thoroughly investigated. Here we allow female participants to manipulate the CIELab a* value (red-green axis) of skin to maximize the perceived aggression, dominance and attractiveness of photographs of men's faces, and make two findings. First, participants increased a* (increasing redness) to enhance each attribute, suggesting that facial redness is perceived as conveying similar information about a male's qualities in humans as it does in non-human species. Second, there were significant differences between trial types: the highest levels of red were associated with aggression, an intermediate level with dominance, and the least with attractiveness. These differences may reflect a trade-off between the benefits of selecting a healthy, dominant partner and the negative consequences of aggression.

Matched MeSH terms: Photography
Fulltext Angiographic anatomy of the extracranial and intracranial portions of the internal carotid arteries in donkeys

Khairuddin NH, Sullivan M, Pollock PJ

Ir Vet J, 2017 04 20;70:12.
PMID: 28439406 DOI: 10.1186/s13620-017-0090-0

BACKGROUND: In horses, the extracranial and intracranial pathway of the internal carotid artery has been described. The extracranial pathway of the internal carotid artery begins at the carotid termination and runs on the dorsal surface of the medial compartment of the guttural pouch. Thereafter the internal carotid artery passes through the foramen lacerum to continue intracranially, forming part of the rostrolateral quadrants of the cerebral arterial circle (Circle of Willis). The objectives of this study were to define and record the anatomy of the carotid arterial tree and the internal carotid artery in donkeys using angiographic techniques. This is a prospective descriptive study on 26 cadaveric donkeys.
METHODS: Twenty six donkey cadavers of mixed, age, sex and use presented for reasons unrelated to disease of the guttural pouch were subjected to carotid and cerebral angiography using rotational angiography. Rotational angiographic and 3 dimensional multiplanar reconstructive (3D-MPR) findings were verified with an arterial latex casting technique followed by dissection and photography.
RESULTS: The following variations of the carotid arterial tree were identified: [1] the internal carotid and occipital arteries shared a common trunk, [2] the linguofacial trunk originated from the common carotid artery causing the common carotid artery to terminate as four branches, [3] the external carotid artery was reduced in length before giving rise to the linguofacial trunk, mimicking the appearance of the common carotid artery terminating in four branches, [4] the internal carotid artery originated at a more caudal position from the common carotid artery termination.
CONCLUSION: Veterinarians should be aware that considerable variation exists in the carotid arterial tree of donkeys and that this variation may differ markedly from that described in the horse.

Matched MeSH terms: Photography
Fulltext Habitat suitability and movement corridors of grey wolf (Canis lupus) in Northern Pakistan

Kabir M, Hameed S, Ali H, Bosso L, Din JU, Bischof R, et al.

PLoS One, 2017;12(11):e0187027.
PMID: 29121089 DOI: 10.1371/journal.pone.0187027

Habitat suitability models are useful to understand species distribution and to guide management and conservation strategies. The grey wolf (Canis lupus) has been extirpated from most of its historic range in Pakistan primarily due to its impact on livestock and livelihoods. We used non-invasive survey data from camera traps and genetic sampling to develop a habitat suitability model for C. lupus in northern Pakistan and to explore the extent of connectivity among populations. We detected suitable habitat of grey wolf using a maximum entropy approach (Maxent ver. 3.4.0) and identified suitable movement corridors using the Circuitscape 4.0 tool. Our model showed high levels of predictive performances, as seen from the values of area under curve (0.971±0.002) and true skill statistics (0.886±0.021). The main predictors for habitat suitability for C. lupus were distances to road, mean temperature of the wettest quarter and distance to river. The model predicted ca. 23,129 km2 of suitable areas for wolf in Pakistan, with much of suitable habitat in remote and inaccessible areas that appeared to be well connected through vulnerable movement corridors. These movement corridors suggest that potentially the wolf range can expand in Pakistan's Northern Areas. However, managing protected areas with stringent restrictions is challenging in northern Pakistan, in part due to heavy dependence of people on natural resources. The habitat suitability map provided by this study can inform future management strategies by helping authorities to identify key conservation areas.

Matched MeSH terms: Photography
Corneal thickness and volume in subclinical and clinical keratoconus

Ahmadi Hosseini SM, Mohidin N, Abolbashari F, Mohd-Ali B, Santhirathelagan CT

Int Ophthalmol, 2013 Apr;33(2):139-45.
PMID: 23138667 DOI: 10.1007/s10792-012-9654-x

To evaluate corneal thickness and volume in subclinical and clinical keratoconus in Asian population with the aim of discriminating between normal and ectatic cornea. Eyes were placed into one of the following three groups: normal, subclinical, and mild-moderate keratoconus. Pentacam Scheimpflug imaging (Oculus Inc., Wetzlar, Germany) was performed for each participant to record thinnest corneal thickness, central corneal thickness, corneal volume (CV), peripheral corneal thickness (PCT) and percentage thickness increase (PTI) at 2, 4, 6, and 8 mm. The data were exported to SPSS for statistical analysis. Subjects comprised 52 normal, 15 subclinical keratoconus, and 32 mild-moderate clinical keratoconus eyes. Our results indicated that corneal thickness (CT) distribution, PTI, and CV in normal eyes were significantly different compared with subclinical and clinical keratoconus (P < .05). Overall, subclinical group exhibited lower CT distribution and volume, and higher PTI in comparison with normal eyes. However, they showed higher CT distribution and volume, and lower PTI compared with keratoconus group. In addition, there was a smaller change in PCT and PTI from the thinnest point of the cornea to the periphery. The results of the present study indicate that CT parameters and CV were significantly different in normal versus subclinical group and in normal versus keratoconus group. These findings could help clinicians to better discriminate between normal and ectatic cornea.

Matched MeSH terms: Photography/methods
A novel shape representation of the dental arch and its applications in some dentistry problems

Rijal OM, Abdullah NA, Isa ZM, Davaei FA, Noor NM, Tawfiq OF

Annu Int Conf IEEE Eng Med Biol Soc, 2011;2011:5092-5.
PMID: 22255484 DOI: 10.1109/IEMBS.2011.6091261

Standardized digital images of maxillary dental casts of 47 subjects were analyzed using MATLAB software whereby the two hamular notches and the incisive papilla defines the Cartesian vertical and horizontal axes, as well as the origin. The angle and length of the midpoints of the anterior teeth, mesiobuccal and distobuccal cusp of the posterior teeth were measured from the origin and denoted as θ(1), …, θ(18) and l(1), …, l(18) respectively. These values were collectively used to represent the shape of each dental cast. Clustering and principal component analyses were employed to find possible groups of dental arches using the above measure of shape. The main result of this study is that the 3 groups of dental arch shape may be represented by the novel feature vector v(k) = (θ(k)(1), l(k)(1), θ(k)(3), l(k)(3), θ(k)(5), l(k)(5), θ(k)(13), l(k)(13)), k = 1, 2, 3. Knowledge of v(k) implies three impression trays should be sufficient in a particular prosthetic dentistry application for Malaysian patients. Further, given that v(k) are accurately measured they may be potential candidates as evidence in specific application of forensic dentistry.

Matched MeSH terms: Photography/methods*
Fulltext Sensitivity and specificity of automated analysis of single-field non-mydriatic fundus photographs by Bosch DR Algorithm-Comparison with mydriatic fundus photography (ETDRS) for screening in undiagnosed diabetic retinopathy

Bawankar P, Shanbhag N, K SS, Dhawan B, Palsule A, Kumar D, et al.

PLoS One, 2017;12(12):e0189854.
PMID: 29281690 DOI: 10.1371/journal.pone.0189854

Diabetic retinopathy (DR) is a leading cause of blindness among working-age adults. Early diagnosis through effective screening programs is likely to improve vision outcomes. The ETDRS seven-standard-field 35-mm stereoscopic color retinal imaging (ETDRS) of the dilated eye is elaborate and requires mydriasis, and is unsuitable for screening. We evaluated an image analysis application for the automated diagnosis of DR from non-mydriatic single-field images. Patients suffering from diabetes for at least 5 years were included if they were 18 years or older. Patients already diagnosed with DR were excluded. Physiologic mydriasis was achieved by placing the subjects in a dark room. Images were captured using a Bosch Mobile Eye Care fundus camera. The images were analyzed by the Retinal Imaging Bosch DR Algorithm for the diagnosis of DR. All subjects also subsequently underwent pharmacological mydriasis and ETDRS imaging. Non-mydriatic and mydriatic images were read by ophthalmologists. The ETDRS readings were used as the gold standard for calculating the sensitivity and specificity for the software. 564 consecutive subjects (1128 eyes) were recruited from six centers in India. Each subject was evaluated at a single outpatient visit. Forty-four of 1128 images (3.9%) could not be read by the algorithm, and were categorized as inconclusive. In four subjects, neither eye provided an acceptable image: these four subjects were excluded from the analysis. This left 560 subjects for analysis (1084 eyes). The algorithm correctly diagnosed 531 of 560 cases. The sensitivity, specificity, and positive and negative predictive values were 91%, 97%, 94%, and 95% respectively. The Bosch DR Algorithm shows favorable sensitivity and specificity in diagnosing DR from non-mydriatic images, and can greatly simplify screening for DR. This also has major implications for telemedicine in the use of screening for retinopathy in patients with diabetes mellitus.

Study site: India

Matched MeSH terms: Photography/methods*
Relationship of maxillary incisors in complete dentures to the incisive papilla

Isa ZM, Abdulhadi LM

J Oral Sci, 2012;54(2):159-63.
PMID: 22790408

We investigated the relationship of the maxillary central incisors to the incisive papilla in wearers of complete dentures. First, image analyzer software was used to examine the relationship of the midpoint of the incisive papilla to the labial surface of the maxillary central incisors on occlusal photographs of 120 maxillary casts from dentate Malaysian adults. Then, an Alma denture gauge was used to identify the position of the labial surface of the maxillary central incisors in relation to the midpoint of the incisive papilla in complete dentures from 51 patients who requested replacement dentures at the Faculty of Dentistry, University of Malaya. The mean incisor distance to the incisive papilla in dentate adults was 9.59 ± 1.00 mm, while the mean incisor distance to the incisive papilla in complete dentures was 6.34 ± 1.87 mm. Thus, in our sample of edentulous patients, the anterior teeth in complete dentures were positioned approximately 3 mm closer to the incisive papilla, as compared with the position of the central incisors in natural dentition, and did not duplicate the position of the natural anterior teeth.

Matched MeSH terms: Photography, Dental/methods
Computerized segmentation and measurement of chronic wound images

Ahmad Fauzi MF, Khansa I, Catignani K, Gordillo G, Sen CK, Gurcan MN

Comput Biol Med, 2015 May;60:74-85.
PMID: 25756704 DOI: 10.1016/j.compbiomed.2015.02.015

An estimated 6.5 million patients in the United States are affected by chronic wounds, with more than US$25 billion and countless hours spent annually for all aspects of chronic wound care. There is a need for an intelligent software tool to analyze wound images, characterize wound tissue composition, measure wound size, and monitor changes in wound in between visits. Performed manually, this process is very time-consuming and subject to intra- and inter-reader variability. In this work, our objective is to develop methods to segment, measure and characterize clinically presented chronic wounds from photographic images. The first step of our method is to generate a Red-Yellow-Black-White (RYKW) probability map, which then guides the segmentation process using either optimal thresholding or region growing. The red, yellow and black probability maps are designed to handle the granulation, slough and eschar tissues, respectively; while the white probability map is to detect the white label card for measurement calibration purposes. The innovative aspects of this work include defining a four-dimensional probability map specific to wound characteristics, a computationally efficient method to segment wound images utilizing the probability map, and auto-calibration of wound measurements using the content of the image. These methods were applied to 80 wound images, captured in a clinical setting at the Ohio State University Comprehensive Wound Center, with the ground truth independently generated by the consensus of at least two clinicians. While the mean inter-reader agreement between the readers varied between 67.4% and 84.3%, the computer achieved an average accuracy of 75.1%.

Matched MeSH terms: Photography
Identification and localization of fovea on colour fundus images using blur scales

Ganesan K, Acharya RU, Chua CK, Laude A

Proc Inst Mech Eng H, 2014 Sep;228(9):962-70.
PMID: 25234036 DOI: 10.1177/0954411914550847

Identification of retinal landmarks is an important step in the extraction of anomalies in retinal fundus images. In the current study, we propose a technique to identify and localize the position of macula and hence the fovea avascular zone, in colour fundus images. The proposed method, based on varying blur scales in images, is independent of the location of other anatomical landmarks present in the fundus images. Experimental results have been provided using the open database MESSIDOR by validating our segmented regions using the dice coefficient, with ground truth segmentation provided by a human expert. Apart from testing the images on the entire MESSIDOR database, the proposed technique was also validated using 50 normal and 50 diabetic retinopathy chosen digital fundus images from the same database. A maximum overlap accuracy of 89.6%-93.8% and locational accuracy of 94.7%-98.9% was obtained for identification and localization of the fovea.

Matched MeSH terms: Photography

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