Automatic colorimetric calibration of human wounds

Contains fulltext : 88431.pdf (publisher's version ) (Open Access)BACKGROUND: Recently, digital photography in medicine is considered an acceptable tool in many clinical domains, e.g. wound care. Although ever higher resolutions are available, reproducibility is still poor and visual comparison of images remains difficult. This is even more the case for measurements performed on such images (colour, area, etc.). This problem is often neglected and images are freely compared and exchanged without further thought. METHODS: The first experiment checked whether camera settings or lighting conditions could negatively affect the quality of colorimetric calibration. Digital images plus a calibration chart were exposed to a variety of conditions. Precision and accuracy of colours after calibration were quantitatively assessed with a probability distribution for perceptual colour differences (dE_ab). The second experiment was designed to assess the impact of the automatic calibration procedure (i.e. chart detection) on real-world measurements. 40 Different images of real wounds were acquired and a region of interest was selected in each image. 3 Rotated versions of each image were automatically calibrated and colour differences were calculated. RESULTS: 1st Experiment: Colour differences between the measurements and real spectrophotometric measurements reveal median dE_ab values respectively 6.40 for the proper patches of calibrated normal images and 17.75 for uncalibrated images demonstrating an important improvement in accuracy after calibration. The reproducibility, visualized by the probability distribution of the dE_ab errors between 2 measurements of the patches of the images has a median of 3.43 dE* for all calibrated images, 23.26 dE_ab for all uncalibrated images. If we restrict ourselves to the proper patches of normal calibrated images the median is only 2.58 dE_ab! Wilcoxon sum-rank testing (p < 0.05) between uncalibrated normal images and calibrated normal images with proper squares were equal to 0 demonstrating a highly significant improvement of reproducibility. In the second experiment, the reproducibility of the chart detection during automatic calibration is presented using a probability distribution of dE_ab errors between 2 measurements of the same ROI. CONCLUSION: The investigators proposed an automatic colour calibration algorithm that ensures reproducible colour content of digital images. Evidence was provided that images taken with commercially available digital cameras can be calibrated independently of any camera settings and illumination features

Journal Club: screen, select, probe & evaluate

Postgraduate dermatology training programs like seminars, panel discussions, and case presentations help residents to acquire knowledge. Journal club (JC) exercises help residents to update themselves with the current literature. What article a resident should choose and how a resident should evaluate and analyze an article or critically appraise a topic are issues that are most relevant for the success of a JC. Little guidance is available in the biomedical literature on how to deal with such issues. The objective of this article is to provide guidance to neophytes on dealing with JC exercises in a way that helps them in learning the critical appraisal skills. A review of the literature and of the author′s experience in JC exercises will be presented. Knowing the methodology of rapid screening of articles along with the art of evaluating them, coupled with a sound knowledge of epidemiology and bio-statistics, helps a resident to select appropriate articles and discard poorly conceived or designed topics that may not generate interest in JC attendees. Hence, such an approach helps the resident in acquiring new knowledge in the shortest time. Choosing the right topic and then applying the newly obtained information to clinical practice, participants succeed in making the JC a valuable learning experience. Further, such well-formatted JCs help residents to improve the quality of health care delivered to patients

Subcorneal Pustular Dermatosis In A Child With Congenital Hypothyroidism : Association Or Co - Incidental

Subcorneal pustular dermatosis (SCPD) is a chronic benign relapsing, pustular eruption with distinctive histology1 affecting usually the females in the age group of 40 yrs. Recently, its association with hyperthyroidism has been reported2. We describe a child with congenital hypothyroidism and SCPD