Clinimetric analysis of recently applied quantitative tools in evaluation of vitiligo treatment.

BACKGROUND: Vitiligo affects about 1% of the world's population, however, there is currently no universally used standardized measure to assess its response to treatment. OBJECTIVE: To find the most effective technique for the quantitative assessment of therapeutic results in vitiligo patients. MATERIALS AND METHODS: The study was performed in three stages: (1) Conducting an adapted Delphi survey to check current dermatologists' attitudes regarding the topic of study. (2) Conducting a pilot study that involves testing the selected digital image analysis software in the laboratory to validate future tasks. (3) The chief clinimetric study that implicates selecting actual vitiligo lesion models and evaluating them. RESULTS: Regarding the surface area measuring techniques, the most accurate results were gained through the digital image analysis for surface area, followed by point-counting technique. The digital image analysis for color measurement was accurate and reliable in getting a percentage representation of color improvement within the vitiligo lesions, in response to therapy. LIMITATIONS: Many dermatologists lack understanding of basic concepts about imaging techniques. The study does not include a traditional assessment method such as vitiligo area scoring index. CONCLUSION: Our designated digital image analysis technique was able to efficiently assess the changes that occur both on surface area and the color of vitiligo lesions in response to therapy.

Digital volumetric measurement of cutaneous leishmaniasis lesions: Blur estimation method.

BACKGROUND: Cutaneous leishmaniasis is a common parasitic infestation in Iran. With recent advantages in digital imaging, we have devised a novel non-contact objective method of measuring lesions. AIM: The aim of the study was to design a software system that analyzes images of cutaneous leishmaniasis lesions, objectively assess and monitor volume. METHODS: A photographic technique along with an image processing algorithm was applied to extract a three-dimensional map of the lesion from a simple two-dimensional picture. This method recovers depth on the basis of blur estimation. A macro lens with a low depth of field was used to blur the objects out of focus. To assess and compare the results, a polymer mold of the corresponding lesion was made and filled with liquid. The volume of liquid corresponded to the volume of the lesion. A total of thirty-seven patients were enrolled, and 48 lesions were analyzed. RESULTS: The mean volume measured by image processing was 159 µl (range: 8-685 µl), in comparison to an average of 170 µl (range: 6-800 µl) obtained from the molds. This was not significantly different. Statistical analysis by the Pearson correlation test showed a 'very good fit' correlation between these measured volumes (P < 0.001, r = 0.938). LIMITATION: The location and height of lesions were two important limitations in implementing this technique. If the lesion location is in the curvature region of body or the lesion height is less than 1 mm or more than 1 cm, this method will lose precision and accuracy. CONCLUSION: Image processing with blur estimation technique is an accurate and precise method to measure the volume of lesions in cutaneous leishmaniasis.

Basic digital photography in dermatology.

Digital photography has virtually replaced conventional film photography as far as clinical imaging is concerned. Though most dermatologists are familiar with digital cameras, there is room for improvement in the quality of clinical images. We aim to give an overview of the basics of digital photography in relation to dermatology, which would be useful to a dermatologist in his or her future clinical practice.