35,670 research outputs found
Digital Breast Tomosynthesis for Dense Breasts
Digital breast tomosynthesis (DBT), also referred to as three-dimensional digital mammography provides a new technique that can aid in dense breast imaging. Mammography is the process of creating images of the breast for screening and diagnostic purposes by using low dose radiation. Screening mammograms are performed once a patient is age forty and then annually after that. It is used to provide an earlier detection of breast cancer for a better chance of survival. Diagnostic mammograms are performed when a patient has a strong family history of breast cancer or clinical evidence, such as, a breast lump. Most cancerous lesions found in the breast have irregular boarders that appear spiculated and as architectural distortions. Dense breast tissue can mask these spiculations. DBT reduces masking and resolves superimposition of breast tissue allowing better discrimination of tissue structures and improves visualization. DBT offers many advantages including improved breast cancer detection, dense breast imaging, and reducing the frequency of false-positive results and recalls.https://digitalcommons.misericordia.edu/medimg_seniorposters/1009/thumbnail.jp
PLS dimension reduction for classification of microarray data
PLS dimension reduction is known to give good prediction accuracy in the context of classification with high-dimensional microarray data. In this paper, PLS is compared with some of the best state-of-the-art classification methods. In addition, a simple procedure to choose the number of components is suggested. The connection between PLS dimension reduction and gene selection is examined and a property of the first PLS component for binary classification is proven. PLS can also be used as a visualization tool for high-dimensional data in the classification framework. The whole study is based on 9 real microarray cancer data sets
Principal manifolds and graphs in practice: from molecular biology to dynamical systems
We present several applications of non-linear data modeling, using principal
manifolds and principal graphs constructed using the metaphor of elasticity
(elastic principal graph approach). These approaches are generalizations of the
Kohonen's self-organizing maps, a class of artificial neural networks. On
several examples we show advantages of using non-linear objects for data
approximation in comparison to the linear ones. We propose four numerical
criteria for comparing linear and non-linear mappings of datasets into the
spaces of lower dimension. The examples are taken from comparative political
science, from analysis of high-throughput data in molecular biology, from
analysis of dynamical systems.Comment: 12 pages, 9 figure
Nipple discharge: the state of the art
Over 80% of females experience nipple discharge during their life. Differently from lactational (milk production) and
physiological (white, green, or yellow), which are usually bilateral and involving multiple ducts, pathologic nipple
discharge (PND) is a spontaneous commonly single-duct and unilateral, clear, serous, or bloody secretion. Mostly
caused by intraductal papilloma(s) or ductal ectasia, in 5-33% of cases is due to an underlying malignancy. After clinical
history and physical examination, mammography is the first step after 39, but its sensitivity is low (7ā26%). Ultrasound
shows higher sensitivity (63ā100%). Nipple discharge cytology is limited by a false negative rate over 50%. Galactography
is an invasive technique that may cause discomfort and pain; it can be performed only when the duct discharge
is demonstrated at the time of the study, with incomplete/failed examination rate up to 15% and a difficult differentiation
between malignant and benign lesions. Ductoscopy, performed under local anesthesia in outpatients, provides a
direct visualization of intraductal lesions, allowing for directed excision and facilitating a targeted surgery. Its sensitivity
reaches 94%; however, it is available in only few centers and most clinicians are unfamiliar with its use. PND has recently
emerged as a new indication for contrast-enhanced breast MRI, showing sensitivity superior to galactography, with an
overall sensitivity up to 96%, also allowing tailored surgery. Surgery no longer can be considered the standard approach
to PND. We propose a state-of-the art flowchart for the management of nipple discharge, including ductoscopy and
breast MRI as best options
Spatial-temporal analysis of breast cancer in upper Cape Cod, Massachusetts
INTRODUCTION. The reasons for elevated breast cancer rates in the upper Cape Cod area of Massachusetts remain unknown despite several epidemiological studies that investigated possible environmental risk factors. Data from two of these population-based case-control studies provide geocoded residential histories and information on confounders, creating an invaluable dataset for spatial-temporal analysis of participants' residency over five decades.
METHODS. The combination of statistical modeling and mapping is a powerful tool for visualizing disease risk in a spatial-temporal analysis. Advances in geographic information systems (GIS) enable spatial analytic techniques in public health studies previously not feasible. Generalized additive models (GAMs) are an effective approach for modeling spatial and temporal distributions of data, combining a number of desirable features including smoothing of geographical location, residency duration, or calendar years; the ability to estimate odds ratios (ORs) while adjusting for confounders; selection of optimum degree of smoothing (span size); hypothesis testing; and use of standard software.
We conducted a spatial-temporal analysis of breast cancer case-control data using GAMs and GIS to determine the association between participants' residential history during 1947ā1993 and the risk of breast cancer diagnosis during 1983ā1993. We considered geographic location alone in a two-dimensional space-only analysis. Calendar year, represented by the earliest year a participant lived in the study area, and residency duration in the study area were modeled individually in one-dimensional time-only analyses, and together in a two-dimensional time-only analysis. We also analyzed space and time together by applying a two-dimensional GAM for location to datasets of overlapping calendar years. The resulting series of maps created a movie which allowed us to
visualize changes in magnitude, geographic size, and location of elevated breast cancer risk for the 40 years of residential history that was smoothed over space and time.
RESULTS. The space-only analysis showed statistically significant increased areas of breast cancer risk in the northern part of upper Cape Cod and decreased areas of breast cancer risk in the southern part (p-value = 0.04; ORs: 0.90ā1.40). There was also a significant association between breast cancer risk and calendar year (p-value = 0.05; ORs: 0.53ā1.38), with earlier calendar years resulting in higher risk. The results of the one-dimensional analysis of residency duration and the two-dimensional analysis of calendar year and duration showed that the risk of breast cancer increased with increasing residency duration, but results were not statistically significant. When we considered space and time together, the maps showed a large area of statistically significant elevated risk for breast cancer near the Massachusetts Military Reservation (p-value range:0.02ā0.05; ORs range: 0.25ā2.5). This increased risk began with residences in the late 1940s and remained consistent in size and location through the late 1950s.
CONCLUSION. Spatial-temporal analysis of the breast cancer data may help identify new exposure hypotheses that warrant future epidemiologic investigations with detailed exposure models. Our methods allow us to visualize breast cancer risk, adjust for known confounders including age at diagnosis or index year, family history of breast cancer, parity and age at first live- or stillbirth, and test for the statistical significance of location and time. Despite the advantages of GAMs, analyses are for exploratory purposes and there are still methodological issues that warrant further research. This paper illustrates that GAM methods are a suitable alternative to widely-used cluster detection methods and may be preferable when residential histories from existing epidemiological studies are available.National Cancer Institute (5R03CA119703-02); National Institute of Enviornmental Health (5P42ES007381
Real-time virtual sonography in gynecology & obstetrics. literature's analysis and case series
Fusion Imaging is a latest generation diagnostic technique, designed to combine ultrasonography with a second-tier technique such as magnetic resonance imaging and computer tomography. It has been mainly used until now in urology and hepatology. Concerning gynecology and obstetrics, the studies mostly focus on the diagnosis of prenatal disease, benign pathology and cervical cancer. We provided a systematic review of the literature with the latest publications regarding the role of Fusion technology in gynecological and obstetrics fields and we also described a case series of six emblematic patients enrolled from Gynecology Department of Sant āAndrea Hospital, āla Sapienzaā, Rome, evaluated with Esaote Virtual Navigator equipment. We consider that Fusion Imaging could add values at the diagnosis of various gynecological and obstetrics conditions, but further studies are needed to better define and improve the role of this fascinating diagnostic tool
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