A deep learning approach to detect blood vessels in basal cell carcinoma.

PURPOSE: Blood vessels called telangiectasia are visible in skin lesions with the aid of dermoscopy. Telangiectasia are a pivotal identifying feature of basal cell carcinoma. These vessels appear thready, serpiginous, and may also appear arborizing, that is, wide vessels branch into successively thinner vessels. Due to these intricacies, their detection is not an easy task, neither with manual annotation nor with computerized techniques. In this study, we automate the segmentation of telangiectasia in dermoscopic images with a deep learning U-Net approach. METHODS: We apply a combination of image processing techniques and a deep learning-based U-Net approach to detect telangiectasia in digital basal cell carcinoma skin cancer images. We compare loss functions and optimize the performance by using a combination loss function to manage class imbalance of skin versus vessel pixels. RESULTS: We establish a baseline method for pixel-based telangiectasia detection in skin cancer lesion images. An analysis and comparison for human observer variability in annotation is also presented. CONCLUSION: Our approach yields Jaccard score within the variation of human observers as it addresses a new aspect of the rapidly evolving field of deep learning: automatic identification of cancer-specific structures. Further application of DL techniques to detect dermoscopic structures and handle noisy labels is warranted.

Thresholding methods for lesion segmentation of basal cell carcinoma in dermoscopy images.

PURPOSE: Algorithms employed for pigmented lesion segmentation perform poorly on dermoscopy images of basal cell carcinoma (BCC), the most common skin cancer. The main objective was to develop better methods for BCC segmentation. METHODS: Fifteen thresholding methods were implemented for BCC lesion segmentation. We propose two error metrics that better measure the type II error: Relative XOR Error and Lesion Capture Ratio. RESULTS: On training/test sets of 305 and 34 BCC images, respectively, five new techniques outperform two state-of-the-art methods used in segmentation of melanomas, based on the new error metrics. CONCLUSION: The proposed algorithms, which include solutions for image vignetting correction and border expansion to achieve dermatologist-like borders, provide more inclusive and feature-preserving border detection, favoring better BCC classification accuracy, in future work.

Real-time supervised detection of pink areas in dermoscopic images of melanoma: importance of color shades, texture and location.

BACKGROUND/PURPOSE: Early detection of malignant melanoma is an important public health challenge. In the USA, dermatologists are seeing more melanomas at an early stage, before classic melanoma features have become apparent. Pink color is a feature of these early melanomas. If rapid and accurate automatic detection of pink color in these melanomas could be accomplished, there could be significant public health benefits. METHODS: Detection of three shades of pink (light pink, dark pink, and orange pink) was accomplished using color analysis techniques in five color planes (red, green, blue, hue, and saturation). Color shade analysis was performed using a logistic regression model trained with an image set of 60 dermoscopic images of melanoma that contained pink areas. Detected pink shade areas were further analyzed with regard to the location within the lesion, average color parameters over the detected areas, and histogram texture features. RESULTS: Logistic regression analysis of a separate set of 128 melanomas and 128 benign images resulted in up to 87.9% accuracy in discriminating melanoma from benign lesions measured using area under the receiver operating characteristic curve. The accuracy in this model decreased when parameters for individual shades, texture, or shade location within the lesion were omitted. CONCLUSION: Texture, color, and lesion location analysis applied to multiple shades of pink can assist in melanoma detection. When any of these three details: color location, shade analysis, or texture analysis were omitted from the model, accuracy in separating melanoma from benign lesions was lowered. Separation of colors into shades and further details that enhance the characterization of these color shades are needed for optimal discrimination of melanoma from benign lesions.

Pretreatment with finasteride decreases perioperative bleeding associated with transurethral resection of the prostate.

OBJECTIVES: The efficacy of finasteride in the treatment of gross hematuria associated with benign prostatic hyperplasia is well established. We evaluated a regimen of pretreatment with finasteride in decreasing perioperative bleeding associated with transurethral resection of the prostate (TURP). METHODS: A prospective analysis compared 25 patients pretreated with finasteride for 2 to 4 months before TURP with 50 patients without pretreatment. Patients in each group were further separated by the amount of prostate tissue resected. Patients were then followed up for perioperative bleeding, defined as a perioperative blood transfusion requirement or a return visit to the emergency room with gross hematuria or clot retention. RESULTS: None of the patients with less than 30 g of prostate tissue resected experienced perioperative bleeding. In patients with 30 g or more resected, several episodes of bleeding occurred. In the patients pretreated with finasteride, 1 (8.3%) of 12 experienced perioperative bleeding; in the control group, 7 (36.8%) of 19 had an episode of bleeding. CONCLUSIONS: In patients with large prostate glands undergoing TURP, pretreatment with finasteride appears useful in reducing perioperative bleeding.

Location and sampling of aqueous and hydrothermal deposits in martian impact craters.

Do large craters on Mars represent sites that contain aqueous and hydrothermal deposits that provide clues to astrobiological processes? Are these materials available for sampling in large craters? Several lines of evidence strongly support the exploration of large impact craters to study deposits important for astrobiology. The great depth of impact craters, up to several kilometers relative to the surrounding terrain, can allow the breaching of local aquifers, providing a source of water for lakes and hydrothermal systems. Craters can also be filled with water from outflow channels and valley networks to form large lakes with accompanying sedimentation. Impact melt and uplifted basement heat sources in craters > 50 km in diameter should be sufficient to drive substantial hydrothermal activity and keep crater lakes from freezing for thousands of years, even under cold climatic conditions. Fluid flow in hydrothermal systems is focused at the edges of large planar impact melt sheets, suggesting that the edge of the melt sheets will have experienced substantial hydrothermal alteration and mineral deposition. Hydrothermal deposits, fine-grained lacustrine sediments, and playa evaporite deposits may preserve evidence for biogeochemical processes that occurred in the aquifers and craters. Therefore, large craters may represent giant Petri dishes for culturing preexisting life on Mars and promoting biogeochemical processes. Landing sites must be identified in craters where access to the buried lacustrine sediments and impact melt deposits is provided by processes such as erosion from outflow channels, faulting, aeolian erosion, or excavation by later superimposed cratering events. Very recent gully formation and small impacts within craters may allow surface sampling of organic materials exposed only recently to the harsh oxidizing surface environment.

Discrimination of squamous cell carcinoma in situ from seborrheic keratosis by color analysis techniques requires information from scale, scale-crust and surrounding areas in dermoscopy images.

Scale-crust, also termed "keratin crust", appears as yellowish-to-tan scale on the skin's surface. It is caused by hyperkeratosis and parakeratosis in inflamed areas of squamous cell carcinoma in situ (SCCIS, Bowen's disease) and is a critical dermoscopy feature for detecting this skin cancer. In contrast, scale appears as a white-to-ivory detaching layer of the skin, without crust, and is most commonly seen in benign lesions such as seborrheic keratoses (SK). Distinguishing scale-crust from ordinary scale in digital dermoscopy images holds promise for early SCCIS detection and differentiation from SK. Reported here are image analysis techniques that best characterize scale-crust in SCCIS and scale in SK, thereby allowing accurate separation of these two dermoscopic features. Classification using a logistic regression operating on color features extracted from these digital dermoscopy structures can reliably separate SCCIS from SK.

Evaluation of the United States pediatric urology workforce and fellowships: a series of surveys performed in 2006-2010.

OBJECTIVE: In the US, there has been an evolution in the practice of pediatric urology from a primary academic sub-specialty focused on reconstruction of major congenital genitorurinary abnormalities to a mixed academic and private practice that serves as the primary care giver for all pediatric urologic concerns. The estimated manpower needs were unable to be resolved, due to our inability to determine the impact of sub-specialty certification on referral patterns, along with the failure to embrace the use of physician extenders. Here, we review a series of surveys performed in 2006-2010 regarding the sub-specialty of pediatric urology. MATERIALS AND METHODS: The four surveys focused on workforce needs, appraised the financial impact of educational debt on the pediatric urology community, and evaluated concerns of the current fellows in training. RESULTS: The median financial income for a pediatric urologist, the resident's educational debt load, and a desire of the fellows to have an open dialog with the urologic community regarding the merits of the research year are revealed. CONCLUSION: We have identified that the ability to recruit fellows into our field is dependent upon a combination of factors: interest in the field, job availability in relationship to geographic locations, mentoring, concerns regarding financial/familial hardships encountered during a 2-year fellowship, and the lack of increased financial reimbursement for the extra training required.

The amino-glycosides.

Nurses are in an excellent position to participate in the prevention of toxic reactions during aminoglycoside therapy. The nurse monitors important parameters and thus has the opportunity to promptly detect warning signs of toxic conditions. Awareness of the toxic potential of aminoglycosides as well as knowledge of the signs and potentiators of toxic reactions can make nurses a vital link in the safe administration of aminoglycosides.

Management of the very weak pelvic floor. Is there a point?

Conservative treatment in the form of pelvic muscle exercises is effective in the treatment of stress urinary incontinence. There are no studies specifically looking at women who have extremely weak pelvic muscles and their response to conservative treatment. This study looks at the effectiveness of pelvic muscle therapy in women with very weak pelvic muscles. Out of 965 women attending the bladder clinic at Kirwan Hospital, 219 were assessed to have weak pelvic muscles by digital palpation. All patients were subjected to a detailed urogynecological questionnaire, a frequency/volume chart, and clinical assessment. All patients were then given detailed verbal and written instructions on good bladder habits, including posture, dietetic habits and pelvic muscle exercises. Of the 219 women, 163 were able to complete their treatment and presented for review. Out of 163 women 118 (72%) reported a subjective improvement; 89 (54%) demonstrated an objective improvement in pelvic muscle strength.