We introduced in a previous paper a time-dependent full-spectrum analysis algorithm speeding up the estimation of the activity of the radionuclides present in a sample. In this paper, we present a new version of the algorithm allowing online estimation. It uses only on a buffer of few segments while keeping the time information by using a time dependent regularization, thus reducing the size of the data matrices and the length of the processing of each iteration.
View Article and Find Full Text PDFPoisson-statistics based spectral unmixing has been shown to be an efficient analysis tool for the radionuclides activity estimation from gamma-ray spectrometry measurements. However, the calculation of the corresponding characteristic limits has not been investigated so far. In this paper, we present the quantification of the decision threshold and the limits of the coverage interval for the metrological use of such spectral unmixing algorithms.
View Article and Find Full Text PDFIn the context of radioactivity measurements, the quantitative analysis of a gamma-ray spectrum depends on the analysis algorithm. To that end, we recently introduced a Poisson statistics-based spectral unmixing approach. However, it also relies on a proper instrument recalibration as well as on an uncertainty estimation, for which no solution has been proposed so far.
View Article and Find Full Text PDFThe problem of sparse Blind Source Separation (BSS) has been extensively studied when the noise is additive and Gaussian. This is however not the case when the measurements follow Poisson or shot noise statistics, which is customary with counting-based measurements. To that purpose, we introduce a novel sparse BSS algorithm coined pGMCA (poisson-Generalized Morphological Component Analysis) that specifically tackles the blind separation of sparse sources from measurements following Poisson statistics.
View Article and Find Full Text PDFSpectral unmixing was investigated for fast spectroscopic identification in γ-emitter mixtures at low-statistics in the case of measurements performed to prevent illegal nuclear material trafficking or for in situ environmental analysis following a radiological or nuclear accident. For that purpose, a multiplicative update algorithm based on full-spectrum analysis was tested in the case of a 3″x3″ NaI(Tl) detector. Automatic decision-making was addressed using Monte Carlo calculations of decision thresholds and detection limits.
View Article and Find Full Text PDFThis paper presents a sparse spectral unmixing algorithm for activity estimation of radionuclides in γ-ray spectrometry. The spectral unmixing method aims to decompose a measured spectrum into spectral signatures of radionuclides, which is sensitive to the choice of the spectral signatures. The sparsity of the solution is imposed to identify the active radionuclides.
View Article and Find Full Text PDFPurpose: Sentinel-lymph-node (SLN) resection seems to minimize systematic axillary-lymph-node dissection (sALND) side effects in operated breast cancer patients. We explored whether SLN resection achieves similar therapeutic outcomes as sALND but with fewer side effects.
Methods: A randomized, controlled, open-label trial with parallel-group design compared sALND restricted to cases with positive SLN biopsy (test arm, n = 774) versus SLN biopsy followed by sALND (control arm, n = 770).
We propose an original concept of compressive sensing (CS) polarimetric imaging based on a digital micromirror (DMD) array and two single-pixel detectors, without using any polarizer. The polarimetric sensitivity of the proposed setup is due to the tiny difference in Fresnel's coefficients of reflecting mirrors, which is exploited here to form an original reconstruction problem including a CS problem and a source-separation task. We show that a two-step approach, tackling each problem successively, is outperformed by a dedicated combined reconstruction method, which is demonstrated in this paper and preferably implemented through a reweighted fast iterative shrinkage-thresholding algorithm.
View Article and Find Full Text PDFBackground: Sentinel Lymph Node Biopsy (SLNB) procedure was found to be an accurate method of staging the axilla in patients with early stage breast cancer. The standard of care for breast cancer patients with positive SLN metastasis includes complete Axillary Lymph Node Dissection (ALND). However, in 40-70% of patients, the SLN is the only involved axillary node.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
June 2012
The mathematical theory of compressed sensing (CS) asserts that one can acquire signals from measurements whose rate is much lower than the total bandwidth. Whereas the CS theory is now well developed, challenges concerning hardware implementations of CS-based acquisition devices--especially in optics--have only started being addressed. This paper presents an implementation of compressive sensing in fluorescence microscopy and its applications to biomedical imaging.
View Article and Find Full Text PDFUnlabelled: Neoadjuvant chemotherapy or hormonal therapy is based on biological data and enables more patients to be treated with breast conserving surgery for locally advanced T2 and T3 without significantly increasing the rates of ipsilateral breast recurrence. Careful consideration of an optimal preoperative planning aims at accurately determining the patterns of primary tumour down staging and at the amount and location of any residual tumour in the breast, besides converting patients from mutilating surgery candidates to candidates for breast conservative procedure. The use of induction chemotherapy has the potential to improve the cosmetic results but free margins must be achieved and surgery must be planned in onco-plastic surgery.
View Article and Find Full Text PDFIEEE Trans Image Process
March 2011
Generalized morphological component analysis (GMCA) is a recent algorithm for multichannel data analysis which was used successfully in a variety of applications including multichannel sparse decomposition, blind source separation (BSS), color image restoration and inpainting. Building on GMCA, the purpose of this contribution is to describe a new algorithm for BSS applications in hyperspectral data processing. It assumes the collected data is a mixture of components exhibiting sparse spectral signatures as well as sparse spatial morphologies, each in specified dictionaries of spectral and spatial waveforms.
View Article and Find Full Text PDFBackground: This study evaluates the relation of the early oestrogen-regulated gene gabarapl1 to cellular growth and its prognostic significance in breast adenocarcinoma.
Methods: First, the relation between GABARAPL1 expression and MCF-7 growth rate was analysed. Thereafter, by performing macroarray and reverse transcriptase quantitative-polymerase chain reaction (RT-qPCR) experiments, gabarapl1 expression was quantified in several histological breast tumour types and in a retrospective cohort of 265 breast cancers.
Purpose: The aim of the present investigation was to evaluate the prognostic significance of urokinase-type plasminogen activator (uPA) and plasminogen activator inhibitor-1 (PAI-1) tissue contents in primary breast adenocarcinoma.
Patients And Methods: Patients from 3 medical centers were included between 1994 and 2001. Biologic factors in tumor extracts were all assayed in the same laboratory.
Background: Skin Sparing Mastectomy (SSM) and immediate breast reconstruction has become increasingly popular as an effective treatment for patients with breast carcinoma. The aim of this study was to evaluate the clinical outcome of skin sparing mastectomy in early breast cancer at a single population-based institution.
Methods: Records of ninety-five consecutive patients with operable breast cancer who had skin-sparing mastectomy and immediate breast reconstructions between 1995 and 2003 were reviewed.
IEEE Trans Image Process
November 2007
In a recent paper, a method called morphological component analysis (MCA) has been proposed to separate the texture from the natural part in images. MCA relies on an iterative thresholding algorithm, using a threshold which decreases linearly towards zero along the iterations. This paper shows how the MCA convergence can be drastically improved using the mutual incoherence of the dictionaries associated to the different components.
View Article and Find Full Text PDFIEEE Trans Image Process
November 2007
Over the last few years, the development of multichannel sensors motivated interest in methods for the coherent processing of multivariate data. Some specific issues have already been addressed as testified by the wide literature on the so-caIled blind source separation (BSS) problem. In this context, as clearly emphasized by previous work, it is fundamental that the sources to be retrieved present some quantitatively measurable diversity.
View Article and Find Full Text PDFAims: The aim of this study was to determine, from a series of cases, the frequency and prognostic factors of invasion of non-sentinel lymph nodes when the axillary sentinel lymph node contains a metastasis < or =2 mm, and thereby select a population in which completion axillary dissection could be omitted.
Methods: Between July 1996 and July 2003, 62 patients, which axillary sentinel lymph node contained a metastasis < or =2 mm had an evaluation of the axillary non-sentinel lymph nodes. Eleven patients had also an evaluation of internal mammary lymph nodes.
Background: Inflammatory pseudotumor of the liver is an infrequent, fibroinflammatory non-neoplastic process of unknown etiology, generally following a benign inflammatory condition. The importance of knowledge of it resides in its similar presentation to other hepatic tumors in clinical picture, radiological appearance, and macroscopic pattern.
Case Report: A 71-year-old woman presented with acute abdominal pain.
The prevalence of BRCA1/2 germ-line mutations was assessed in a prospective population-based series of early-onset breast cancer (BC) patients in France, and the usefulness of a clinical assessment of hereditary BC risk, based on multiple criteria including pedigree structure, was evaluated. Through the Rhone region BC registry, 232 women diagnosed with BC before 46 years of age were included. They were tested for BRCA1/2 mutations an average of 10 months after diagnosis.
View Article and Find Full Text PDFFollow up for epithelial ovarian carcinomas is not standardized. A close follow-up every three months during three years, and then twice a year during five years seems to be acceptable. Recurrences after primary treatment of ovarian cancer have very bad prognosis.
View Article and Find Full Text PDFThe adrenal gland can frequently be the site of metastatic deposits, including malignant melanocytic tumors; however, primary melanoma of the adrenal gland is exceptional. We reviewed 18 cases reported in the English literature to date, and here add another case which occurred in a 78-year-old man. The patient underwent right suprarenalectomy and the pathology report showed a malignant melanoma of the adrenal gland.
View Article and Find Full Text PDFBackground: Hospital claims databases from acute care units are available nationwide and contain most patients at the beginning of their cancer. The goal is to define the ability of these databases to provide a number of incident breast cancer cases using identification methods. Two identification methods were assessed in three specialized sections of a teaching hospital.
View Article and Find Full Text PDFThirty-five patients with clinically N0 cancers of the canal anal, 33 epidermoid carcinomas et 2 melanomas were histologically staged with inguinal sentinel lymph node biopsy (ISN). With the combined technique, blue dye and radiocolloid the ISN was identified in 100% of the cases. The ISN was invaded in 7 cases/33 for epidermoid tumors and 2/2 for melanomas.
View Article and Find Full Text PDFBackground: The primary management of adult soft tissue sarcomas (STS) is characterized by heterogeneity across centers. Several studies suggest that it is improved when coordinated by specialized sarcoma centers.
Patients And Methods: This study, comparing STS patients of the Rhône-Alpes region treated within and outside the cancer network, retrospectively assesses the conformity of medical practice with 'evidence-based medicine' (EBM) reported under the clinical practice guidelines (CPGs) of the French Federation of Cancer Centers.