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Publicações

Publicações por CTM

2007

Factors determining esthetic outcome after breast cancer conservative treatment

Autores
Cardoso, MJ; Cardoso, J; Santos, AC; Vrieling, C; Christie, D; Liljegren, G; Azevedo, I; Johansen, J; Rosa, J; Amaral, N; Saaristo, R; Sacchini, V; Barros, H; Oliveira, MC;

Publicação
BREAST JOURNAL

Abstract
The aim of this study was to evaluate the factors that determine esthetic outcome after breast cancer conservative treatment, based on a consensual classification obtained with an international consensus panel. Photographs were taken from 120 women submitted to conservative unilateral breast cancer surgery (with or without axillary surgery) and radiotherapy. The images were sent to a panel of observers from 13 different countries and consensus on the classification of esthetic result (recorded as excellent, good, fair or poor) was obtained in 113 cases by means of a Delphi method. For each patient, data were collected retrospectively regarding patient characteristics, tumor, and treatment factors. Univariate and multivariate analysis were used to evaluate the correlation between these factors and overall cosmetic results. On univariate analysis, younger and thinner patients as well as patients with lower body mass index (BMI) and premenopausal status obtained better cosmetic results. In the group of tumor- and treatment-related factors, larger removed specimens, clearly visible scars, the use of chemotherapy and longer follow-up period were associated with less satisfactory results. On multivariate analysis, only BMI and scar visibility maintained a significant association with cosmesis. BMI and scar visibility are the only factors significantly associated with cosmetic results of breast cancer conservative treatment, as evaluated by an international consensus panel.

2007

A shortest path approach for staff line detection

Autores
Rebelo, A; Capela, A; Pinto da Costa, JF; Guedes, C; Carrapatoso, E; Cardoso, JS;

Publicação
AXMEDIS 2007: THIRD INTERNATIONAL CONFERENCE ON AUTOMATED PRODUCTION OF CROSS MEDIA CONTENT FOR MULTI-CHANNEL DISTRIBUTION, PROCEEDINGS

Abstract
Many music works produced in the past still exist only as original manuscripts or as photocopies. Preserving them entails their digitalization and consequent accessibility in a digital format easy-to-manage. The manual process to carry out this task is very time consuming and error prone. Optical music recognition (OMR) is a form of structured document image analysis where music symbols are isolated and identified so that the music can be conveniently processed. While OMR systems perform well on printed scores, current methods for reading handwritten musical scores by computers remain far from ideal. One of the fundamental stages of this process is the staff line detection. In this paper a new method for the automatic detection of music stave lines based on a shortest path approach is presented. Lines with some curvature, discontinuities, and inclination are robustly detected. The proposed algorithm behaves favourably when compared experimentally with well-established algorithms.

2007

Matched filtering and parameter estimation of ringdown waveforms

Autores
Berti, E; Cardoso, J; Cardoso, V; Cavaglia, M;

Publicação
PHYSICAL REVIEW D

Abstract
Using recent results from numerical relativity simulations of nonspinning binary black hole mergers, we revisit the problem of detecting ringdown waveforms and of estimating the source parameters, considering both LISA and Earth-based interferometers. We find that Advanced LIGO and EGO could detect intermediate-mass black holes of mass up to similar to 10(3)M(circle dot) out to a luminosity distance of a few Gpc. For typical multipolar energy distributions, we show that the single-mode ringdown templates presently used for ringdown searches in the LIGO data stream can produce a significant event loss (> 10% for all detectors in a large interval of black hole masses) and very large parameter estimation errors on the black hole's mass and spin. We estimate that more than similar to 10(6) templates would be needed for a single-stage multimode search. Therefore, we recommend a "two-stage" search to save on computational costs: single-mode templates can be used for detection, but multimode templates or Prony methods should be used to estimate parameters once a detection has been made. We update estimates of the critical signal-to-noise ratio required to test the hypothesis that two or more modes are present in the signal and to resolve their frequencies, showing that second-generation Earth-based detectors and LISA have the potential to perform no-hair tests.

2007

Turning subjective into objective: The BCCT.core software for evaluation of cosmetic results in breast cancer conservative treatment

Autores
Cardoso, MJ; Cardoso, J; Amaral, N; Azevedo, I; Barreau, L; Bernardo, M; Christie, D; Costa, S; Fitzal, F; Fougo, JL; Johansen, J; Macmillan, D; Mano, MP; Regolo, L; Rosa, J; Teixeira, L; Vrieling, C;

Publicação
BREAST

Abstract
Twelve expert observers from nine different countries convened in a workshop to evaluate the validity of the Breast Cancer Conservative Treatment. Cosmetic results (BCCT.core) software, an objective method for the aesthetic evaluation of breast cancer conservative treatment. Experts were initially asked to subjectively classify the aesthetic results of 30 photographed cases submitted to breast cancer conservative treatment according to the four-point Harris scale. It was pre-established that if at least two-thirds [Cardoso MJ, Cardoso J, Santos AC, Barros H, Oliveira MC. Interobserver agreement and consensus over the esthetic evaluation of conservative treatment for breast cancer. Breast 2005] of participants provided the same classification this would be considered a consensual evaluation for that case. For cases where such agreement was not reached, consensus was obtained using a nominal group technique. Experts then individually performed objective evaluation of the same set of photographs using the BCCT.core software. This provides an automatic rating of aesthetic results, once scale and reference points in the photograph have been chosen. Agreement between observers, between each observer and the consensus, for computer evaluation obtained by the different participants and between software and consensus was calculated using multiple kappa (k) and weighted kappa (wk) statistics. In the subjective assessment, first-round consensus was achived in 17 (57%) cases. Overall interobserver agreement was fair to moderate (k = 0.40, wk = 0.57). In the objective assessment there was a higher level of concordance between participants (k = 0.86, wk = 0.90). Agreement between software and consensus classification was fair (k = 0.34, wk = 0.53), but was higher in the 17 cases that reached first-round consensus (k = 0.60, wk = 0.73). Merging the two middle classes of the Harris scale, to form a three-point scale, led to an improvement of all non-weighted measures of agreement. These results show that the BCCT.core software provides consistent evaluation of cosmesis. It has the potential to become a gold standard method for assessment of breast cosmesis in clinical trials, as it can be used simultaneously by a panel of observers from different parts of the world to provide more reliable assessments than has been possible previously.

2007

Breast contour detection for the aesthetic evaluation of breast cancer conservative treatment

Autores
Cardoso, JS; Cardoso, MJ;

Publicação
Advances in Soft Computing

Abstract
Cosmetic assessment of breast cancer conservative treatment (BCCT) plays a major role in the evaluation of this form of treatment. Objective assessment methods are being preferred to overcome the drawbacks of subjective evaluation. A recent computer-aided medical system was developed to objectively and automatically perform the aesthetic evaluation of the result of BCCT. In order to extract relevant features from the image, the detection of the breast contour is necessary. In this paper an algorithm based on the shortest path on a graph is proposed to detect the breast contour. The proposed method was applied to 300 breast images with an accuracy of 98%. © 2007 Springer-Verlag Berlin Heidelberg.

2007

Object segmentation using background modelling and cascaded change detection

Autores
Teixeira, LF; Cardoso, JS; Corte Real, L;

Publicação
Journal of Multimedia

Abstract
The automatic extraction and analysis of visual information is becoming generalised. The first step in this processing chain is usually separating or segmenting the captured visual scene in individual objects. Obtaining a perceptually correct segmentation is however a cumber some task. Moreover, typical applications relying on object segmentation, such as visual surveillance, introduce two additional requirements: (1) it should represent only a small fraction of the total amount of processing time and (2) realtime overall processing. We propose a technique that tackles these problems using a cascade of change detection tests, including noise-induced, illumination variation and structural changes. An objective comparison of common pixelwise modelling methods is first done. A cost-based partition- distance between segmentation masks is introduced and used to evaluate the methods. Both the mixture of Gaussians and the kernel density estimation are used as a base to detect structural changes in the proposed algorithm. Experimental results show that the cascade technique consistently outperforms the base methods, without additional post-processing and without additional processing overheads. © 2007 ACADEMY PUBLISHER.

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