Automatic detection of the nipple in screen-film and full-field digital mammograms using a novel Hessian-based method.

Automatic detection of the nipple in mammograms is an important step in computerized systems that combine multiview information for accurate detection and diagnosis of breast cancer. Locating the nipple is a difficult task owing to variations in image quality, presence of noise, and distortion and displacement of the breast tissue due to compression. In this work, we propose a novel Hessian-based method to locate automatically the nipple in screen-film and full-field digital mammograms (FFDMs). The method includes detection of a plausible nipple/retroareolar area in a mammogram using geometrical constraints, analysis of the gradient vector field by mean and Gaussian curvature measurements, and local shape-based conditions. The proposed procedure was tested on 566 mammographic images consisting of 372 randomly selected scanned films from two public databases (mini-MIAS and DDSM), and 194 digital mammograms acquired with a GE Senographe 2000D FFDM system. A radiologist independently marked the centers of the nipples for evaluation of the results. The average error obtained was 6.7 mm (22 pixels) with reference to the center of the nipple as identified by the radiologist. Only two out of the 566 detected nipples (0.35 %) had an error larger than 50 mm. The method was also directly compared with two other techniques for the detection of the nipple. The results indicate that the proposed method outperforms other algorithms presented in the literature and can be used to identify accurately the nipple on various types of mammographic images.

Allergic contact dermatitis with a fertilizer containing hydrogen cyanamide (Dormex).

Cyanamide is a chemical substance used in the treatment of chronic alcoholism as well in agriculture as a fertilizer. We report the case of a 28-year-old healthy non-atopic man that developed a severe skin eruption after the accidental penetration of a small amount of Dormex (a plant growth regulator containing cyanamide) through the patient's gloves. Patch tests revealed positive reactions to Dormex 1% pet. and cyanamide at a dilution of 0.1% pet. and 1% pet. We discuss the causes of sensitization in a patients that regularly used protective measures during anti-parasites treatments.

Application of fractal analysis to mammography.

We report on a morphological study of 192 breast masses as seen in mammograms, with the aim of discrimination between benign masses and malignant tumors. From the contour of each mass, we computed the fractal dimension (FD) and a few shape factors, including compactness, fractional concavity, and spiculation index. We calculated FD using four different methods: the ruler and box-counting methods applied to each 2-dimensional (2D) contour and its 1-dimensional signature. The ANOVA test indicated statistically significant differences in the values of the various shape features between benign masses and malignant tumors. Analysis using receiver operating characteristics indicated the area under the curve, A(z), of up to 0.92 with the individual shape features. The combination of compactness, FD with the 2D ruler method, and the spiculation index resulted in the highest A(z) value of 0.93.

Contact dermatitis with clostridiopeptidase A contained in Noruxol ointment.

Clostridiopeptidase A, also called collagenase 1, is a proteolytic enzyme capable of digesting collagen. Preparations containing clostridiopeptidase A are used topically for the debridement of dermal ulcers, burns and other necrotic lesions to facilitate the formation of granulation tissue and subsequent epithelization. We observed 4 patients with a periulcerative eczema after repeated applications of Noruxol ointment (Smith & Nephew Ltd, L Hull, UK). Patch testing with Noruxol ointment as is and its excipients (soft paraffin and white petrolatum), as well as scaled dilutions of the main ingredient of this topical preparation, clostridiopeptidase A (Firma, Florence, Italy), showed doubtful reactions to Noruxol ointment in 3 patients and a positive reactions only in 1 patient. All patients showed positive reactions to clostridiopeptidase A 1% in pet. This study shows the sensitizing capacity of clostridiopeptidase A that should be tested in all patients with suspect sensitization to Noruxol ointment.