A deep learning classifier for digital breast tomosynthesis.

PURPOSE: To develop a computerized detection system for the automatic classification of the presence/absence of mass lesions in digital breast tomosynthesis (DBT) annotated exams, based on a deep convolutional neural network (DCNN). MATERIALS AND METHODS: Three DCNN architectures working at image-level (DBT slice) were compared: two state-of-the-art pre-trained DCNN architectures (AlexNet and VGG19) customized through transfer learning, and one developed from scratch (DBT-DCNN). To evaluate these DCNN-based architectures we analysed their classification performance on two different datasets provided by two hospital radiology departments.DBT slice images were processed following normalization, background correction and data augmentation procedures. The accuracy, sensitivity, and area-under-the-curve (AUC) values were evaluated on both datasets, using receiver operating characteristic curves. A Grad-CAM technique was also implemented providing anindication of the lesion position in the DBT slice. RESULTS: Accuracy, sensitivity and AUC for the investigated DCNN are in-line with the best performance reported in the field. The DBT-DCNN network developed in this work showed an accuracy and a sensitivity of (90% ± 4%) and (96% ± 3%), respectively, with an AUC as good as 0.89 ± 0.04. Ak-fold cross validation test (withk = 4) showed an accuracy of 94.0% ± 0.2%, and a F1-score test provided a value as good as 0.93 ± 0.03. Grad-CAM maps show high activation in correspondence of pixels within the tumour regions. CONCLUSIONS: We developed a deep learning-based framework (DBT-DCNN) to classify DBT images from clinical exams. We investigated also apossible application of the Grad-CAM technique to identify the lesion position.

A biologically inspired meta-control navigation system for the Psikharpax rat robot.

A biologically inspired navigation system for the mobile rat-like robot named Psikharpax is presented, allowing for self-localization and autonomous navigation in an initially unknown environment. The ability of parts of the model (e.g. the strategy selection mechanism) to reproduce rat behavioral data in various maze tasks has been validated before in simulations. But the capacity of the model to work on a real robot platform had not been tested. This paper presents our work on the implementation on the Psikharpax robot of two independent navigation strategies (a place-based planning strategy and a cue-guided taxon strategy) and a strategy selection meta-controller. We show how our robot can memorize which was the optimal strategy in each situation, by means of a reinforcement learning algorithm. Moreover, a context detector enables the controller to quickly adapt to changes in the environment-recognized as new contexts-and to restore previously acquired strategy preferences when a previously experienced context is recognized. This produces adaptivity closer to rat behavioral performance and constitutes a computational proposition of the role of the rat prefrontal cortex in strategy shifting. Moreover, such a brain-inspired meta-controller may provide an advancement for learning architectures in robotics.

Accuracy of epiluminescence microscopy among practical dermatologists: a study from the Emilia-Romagna region of Italy.

AIMS AND BACKGROUND: The accuracy of epiluminescence microscopy (ELM) for pigmented skin lesions (PSLs) is still unclear. The large scale utilization of the technique is generally discouraged. The present study was aimed at comparing the accuracy of ELM with that of clinical examination alone in a group of 20 practical dermatologists. METHODS AND STUDY DESIGN: Thirty digital clinical images of benign and malignant PSLs and their digital ELM counterparts were used. A set of cumulative accuracy measures reported in the combined clinical/ELM diagnosis was compared with that reported in the clinical diagnosis alone. RESULTS: The proportion of nonmelanocytic lesions (NMLs), melanocytic nevi, and melanomas correctly identified, the predictive value of such diagnoses, and the proportion of melanomas detected by referral for biopsy (irrespective of the diagnosis reported) increased significantly. The cases referred for biopsy despite a "benign" impression decreased significantly among NMLs. CONCLUSIONS: The observed tendency towards a greater accuracy suggests that even in the routine dermatology practice ELM has the potential to improve the clinical examination of PSLs.

Occupational dermatitis in animal feed mill workers.

In an epidemiological study of occupational dermatitis in 15 different northern Italian animal feed mills, 204 workers were interviewed, examined and patch tested to 34 allergens, selected from the additives most commonly used in the animal feed mills under consideration. The prevalence of occupational contact dermatitis was 13.7% (28/204): 7.8% (16/204) irritant contact dermatitis and 5.8% (12/204) allergic contact dermatitis from animal feed additives. Among the latter, there were sensitizations, to our knowledge hitherto unreported in the literature: to indigo carmine (2 cases), monensin sodium (1 case), thiabendazole (1 case), methylchlorpindol (1 case) and amprolium hydrochloride (1 case). 3.9% (8/204) of the workers complained only of pruritus sine materia on exposed areas of the body. Contact dermatitis increased with respect to duration of employment: the difference in the rate of contact dermatitis between workers employed in animal feed mill for greater than 10 years and those employed for less than 10 years was statistically significant (p less than 0.05). 6.8% (14/204) had latent sensitivity, which was more frequent in workers with less than 1 year of employment with respect to more experienced colleagues.

Iso-intense gallium uptake in hepatocellular carcinoma: potential pitfalls in diagnosis.

Twenty-one patients with hepatocellular carcinoma who had gallium scans were retrospectively reviewed. Four of them demonstrated iso-intense gallium uptake compared to the adjacent liver parenchyma. The importance is therefore emphasized of using radiocolloid scan with tracer angiogram performed at the same time in order to avoid the potential diagnostic pitfall of not recognizing the tumor on gallium scan alone.

Extravasation from the unused bladder during cystography: case report.

Spontaneous, asymptomatic extravasation during retrograde cystography occurred in a quadraplegic patient who had been maintained on constant Foley catheter drainage for 7 years. This phenomenon has recently been described in a few anuric patients being studied prior to renal transplant and is probably related to the chronic disuse status of the bladder. It is a self-limiting process and, in the absence of a clinical reaction, only observation is warranted.