Search results for "mammography"
showing 10 items of 69 documents
Comparative Study of Feature classification Methods for Mass Lesion Recognition in Digitized Mammograms
2007
In this work a comparison of different classification methods for the identification of mass lesions in digitized mammograms is performed. These methods, used in order to develop Computer Aided Detection (CAD) systems, have been implemented in the framework of the MAGIC-5 Collaboration. The system for identification of mass lesions is based on a three-step procedure: a) preprocessing and segmentation, b) region of interest (ROI) searching, c) feature extraction and classification. It was tested on a very large mammographic database (3369 mammographic images from 967 patients). Each ROI is characterized by eight features extracted from a co-occurrence matrix containing spatial statistics inf…
Underuse of long-term routine hospital follow-up care in patients with a history of breast cancer?
2011
Abstract Background After primary treatment for breast cancer, patients are recommended to use hospital follow-up care routinely. Long-term data on the utilization of this follow-up care are relatively rare. Methods Information regarding the utilization of routine hospital follow-up care was retrieved from hospital documents of 662 patients treated for breast cancer. Utilization of hospital follow-up care was defined as the use of follow-up care according to the guidelines in that period of time. Determinants of hospital follow up care were evaluated with multivariate analysis by generalized estimating equations (GEE). Results The median follow-up time was 9.0 (0.3-18.1) years. At fifth and…
Mammographic images segmentation based on chaotic map clustering algorithm
2013
Background: This work investigates the applicability of a novel clustering approach to the segmentation of mammographic digital images. The chaotic map clustering algorithm is used to group together similar subsets of image pixels resulting in a medically meaningful partition of the mammography. Methods: The image is divided into pixels subsets characterized by a set of conveniently chosen features and each of the corresponding points in the feature space is associated to a map. A mutual coupling strength between the maps depending on the associated distance between feature space points is subsequently introduced. On the system of maps, the simulated evolution through chaotic dynamics leads…
Calorie intake, olive oil consumption and mammographic density among Spanish women
2013
High mammographic density (MD) is one of the main risk factors for development of breast cancer. To date, however, relatively few studies have evaluated the association between MD and diet. In this cross-sectional study, we assessed the association between MD (measured using Boyd's semiquantitative scale with five categories: 75%) and diet (measured using a food frequency questionnaire validated in a Spanish population) among 3,548 peri- and postmenopausal women drawn from seven breast cancer screening programs in Spain. Multivariate ordinal logistic regression models, adjusted for age, body mass index (BMI), energy intake and protein consumption as well as other confounders, showed an asso…
Classifier trained on dissimilarity representation of medical pattern: A comparative study.
2005
In this paper we investigate the feasibility of some typical techniques of pattern recognition for the classification of medical examples. The learning of the classifiers is not made in the traditional features space but it can be made by constructing decision rules on dissimilarity (distance) representations. In such a recognition process a new object is described by its distances to (a subset of) the training samples. Purpose of this work is the development of an automatic classification system which could be useful for radiologists in the investigation of breast cancer. The software has been designed in the framework of the MAGIC-5 collaboration. In the automatic classification system th…
Direct Measurement of Mammographic X-Ray Spectra with a Digital CdTe Detection System
2012
In this work we present a detection system, based on a CdTe detector and an innovative digital pulse processing (DPP) system, for high-rate X-ray spectroscopy in mammography (1–30 keV). The DPP system performs a height and shape analysis of the detector pulses, sampled and digitized by a 14-bit, 100 MHz ADC. We show the results of the characterization of the detection system both at low and high photon counting rates by using monoenergetic X-ray sources and a nonclinical X-ray tube. The detection system exhibits excellent performance up to 830 kcps with an energy resolution of 4.5% FWHM at 22.1 keV. Direct measurements of clinical molybdenum X-ray spectra were carried out by using a pinhole…
Preoperative assessment of breast cancer: sonography versus MR imaging.
2002
The purposes of our study were to compare the diagnostic value of whole-breast sonography and MR imaging as adjunctive techniques to mammography and to determine whether MR imaging should be used routinely in the preoperative assessment of patients with suspected breast cancer.. One hundred four women (age range, 34-84 years; mean age, 60 years) with findings highly suggestive of malignancy in the breast were examined with mammography, sonography, and dynamic MR imaging before undergoing surgery. All visualized suspicious lesions were correlated histologically. The diagnostic relevance of sonographic and MR imaging findings was compared with the diagnostic value of the findings of clinical …
Spiral-Computertomographie der Mamma
1994
Aim To evaluate the use of spiral CT in the diagnosis of breast lesions. Material and methods 93 female patients with suspicious or uncertain mammographic findings were examined by CT before and after contrast enhancement according to the following practical method: table movement, 6 mm/s, slice thickness 6 mm, increment 4 mm, contrast 200 ml, injection rate 3 ml/s, scan start 50 s after the beginning of the injection. Histological confirmation was present in 85 patients. Results All 44 invasive carcinomas were recognised. They were characterised by intensive focal contrast uptake. Only 2 out of 7 intraductal carcinomas were not shown by CT. 36 out of 38 benign lesions were correctly diagno…
Detection of TP53 and PIK3CA Mutations in Circulating Tumor DNA Using Next-Generation Sequencing in the Screening Process for Early Breast Cancer Dia…
2019
Circulating tumor DNA (ctDNA) has emerged as a non-invasive &ldquo
A mammographic phantom image reconstruction through Monte Carlo techniques
2005
Mammographic phantoms are employed during quality control test in breast screening locations and other health centres. These quality controls are performed to achieve the image quality required to detect breast abnormalities, ensuring the minimum risk to radiographied women. The aim of this study is the development of a methodology to reproduce the image of a mammogram during a routine exposure in a breast screening programme. In a first step, the CIRS 11A (MAMMO PHANTOM SP01) mammographic phantom has been simplified and modelled with the Monte Carlo transport code MCNP-4c2. Different tallies (F2 and F5) have been used to score the photon flux under the phantom, and a group of aluminium lay…