Numerical methods for coupled reconstruction and registration in digital breast tomosynthesis.

Digital Breast Tomosynthesis (DBT) provides an insight into the fine details of normal fibroglandular tissues and abnormal lesions by reconstructing a pseudo-3D image of the breast. In this respect, DBT overcomes a major limitation of conventional X-ray mam- mography by reducing the confounding effects caused by the superposition of breast tissue. In a breast cancer screening or diagnostic context, a radiologist is interested in detecting change, which might be indicative of malignant disease. To help automate this task image registration is required to establish spatial correspondence between time points. Typically, images, such as MRI or CT, are first reconstructed and then registered. This approach can be effective if reconstructing using a complete set of data. However, for ill-posed, limited-angle problems such as DBT, estimating the deformation is com- plicated by the significant artefacts associated with the reconstruction, leading to severe inaccuracies in the registration. This paper presents a mathematical framework, which couples the two tasks and jointly estimates both image intensities and the parameters of a transformation. Under this framework, we compare an iterative method and a simultaneous method, both of which tackle the problem of comparing DBT data by combining reconstruction of a pair of temporal volumes with their registration. We evaluate our methods using various computational digital phantoms, uncom- pressed breast MR images, and in-vivo DBT simulations. Firstly, we compare both iter- ative and simultaneous methods to the conventional, sequential method using an affine transformation model. We show that jointly estimating image intensities and parametric transformations gives superior results with respect to reconstruction fidelity and regis- tration accuracy. Also, we incorporate a non-rigid B-spline transformation model into our simultaneous method. The results demonstrate a visually plausible recovery of the deformation with preservation of the reconstruction fidelity

Nonrigid reconstruction of 3D breast surfaces with a low-cost RGBD camera for surgical planning and aesthetic evaluation

Accounting for 26% of all new cancer cases worldwide, breast cancer remains the most common form of cancer in women. Although early breast cancer has a favourable long-term prognosis, roughly a third of patients suffer from a suboptimal aesthetic outcome despite breast conserving cancer treatment. Clinical-quality 3D modelling of the breast surface therefore assumes an increasingly important role in advancing treatment planning, prediction and evaluation of breast cosmesis. Yet, existing 3D torso scanners are expensive and either infrastructure-heavy or subject to motion artefacts. In this paper we employ a single consumer-grade RGBD camera with an ICP-based registration approach to jointly align all points from a sequence of depth images non-rigidly. Subtle body deformation due to postural sway and respiration is successfully mitigated leading to a higher geometric accuracy through regularised locally affine transformations. We present results from 6 clinical cases where our method compares well with the gold standard and outperforms a previous approach. We show that our method produces better reconstructions qualitatively by visual assessment and quantitatively by consistently obtaining lower landmark error scores and yielding more accurate breast volume estimates

A comparative study of breast surface reconstruction for aesthetic outcome assessment

Breast cancer is the most prevalent cancer type in women, and while its survival rate is generally high the aesthetic outcome is an increasingly important factor when evaluating different treatment alternatives. 3D scanning and reconstruction techniques offer a flexible tool for building detailed and accurate 3D breast models that can be used both pre-operatively for surgical planning and post-operatively for aesthetic evaluation. This paper aims at comparing the accuracy of low-cost 3D scanning technologies with the significantly more expensive state-of-the-art 3D commercial scanners in the context of breast 3D reconstruction. We present results from 28 synthetic and clinical RGBD sequences, including 12 unique patients and an anthropomorphic phantom demonstrating the applicability of low-cost RGBD sensors to real clinical cases. Body deformation and homogeneous skin texture pose challenges to the studied reconstruction systems. Although these should be addressed appropriately if higher model quality is warranted, we observe that low-cost sensors are able to obtain valuable reconstructions comparable to the state-of-the-art within an error margin of 3 mm.Comment: This paper has been accepted to MICCAI201

Negative emotional reactivity as a marker of vulnerability in the development of borderline personality disorder symptoms

Negative emotionality is a distinguishing feature of borderline personality disorder (BPD). However, this person-level characteristic has not been examined as a marker of vulnerability in the development of this disorder. The current study utilized a multi-method approach to examine the interplay between negative emotional reactivity and cumulative exposure to family adversity on the development of BPD symptoms across three years (ages 16–18) in a diverse, at-risk sample of adolescent girls (N=113). A latent variable of negative emotional reactivity was created from multiple assessments at age 16: (1) self-report, (2) emotion ratings to stressors from ecological assessments across one week, and (3) observer-rated negative affectivity during a mother-daughter conflict discussion task. Exposure to family adversity was measured cumulatively between ages 5 and 16 from annual assessments of family poverty, single parent household, and difficult life circumstances. Results from latent growth curve models demonstrated a significant interaction between negative emotional reactivity and family adversity, such that exposure to adversity strengthened the association between negative emotional reactivity and BPD symptoms. Additionally, family adversity predicted increasing BPD symptoms during late adolescence. These findings highlight negative emotional reactivity as a marker of vulnerability that ultimately increases risk for the development of BPD symptoms

Combined Reconstruction and Registration of Digital Breast Tomosynthesis

Digital breast tomosynthesis (DBT) has the potential to en- hance breast cancer detection by reducing the confounding e ect of su- perimposed tissue associated with conventional mammography. In addi- tion the increased volumetric information should enable temporal datasets to be more accurately compared, a task that radiologists routinely apply to conventional mammograms to detect the changes associated with ma- lignancy. In this paper we address the problem of comparing DBT data by combining reconstruction of a pair of temporal volumes with their reg- istration. Using a simple test object, and DBT simulations from in vivo breast compressions imaged using MRI, we demonstrate that this com- bined reconstruction and registration approach produces improvements in both the reconstructed volumes and the estimated transformation pa- rameters when compared to performing the tasks sequentially

The challenge of parenting girls in neighborhoods of different perceived quality

It is well-known that disadvantaged neighborhoods, as officially identified through census data, harbor higher numbers of delinquent individuals than advantaged neighborhoods. What is much less known is whether parents’ perception of the neighborhood problems predicts low parental engagement with their girls and, ultimately, how this is related to girls’ delinquency, including violence. This paper elucidates these issues by examining data from the Pittsburgh Girls Study, including parent-report of neighborhood problems and level of parental engagement and official records and girl-reported delinquency at ages 15, 16, and 17. Results showed higher stability over time for neighborhood problems and parental engagement than girls’ delinquency. Parents’ perception of their neighborhood affected the extent to which parents engaged in their girls’ lives, but low parental engagement did not predict girls being charged for offending at age 15, 16 or 17. These results were largely replicated for girls’ self-reported delinquency with the exception that low parental engagement at age 16 was predictive of the frequency of girls’ self-reported delinquency at age 17 as well. The results, because of their implications for screening and early interventions, are relevant to policy makers as well as practitioners

Abordajes de nuevos tratamientos para la enfermedad de Chagas y su potencial aplicación en pacientes desde las perspectivas de los profesionales en la Ciudad Autónoma de Buenos Aires, Argentina / Approaches to New Treatments for Chagas Disease and their Potential Application in Patients from the Perspectives of Professionals in the Autonomous City of Buenos Aires, Argentina

Más de cien años después del descubrimiento de la enfermedad de Chagas, esta enfermedad desatendida sigue afectando más de 6 millones de personas en Latinoamérica, de las cuales 1.5 millones son de Argentina. Al día de hoy, solo existen dos medicamentos para tratar esta enfermedad. El presente proyecto se basa sobre un estudio exploratorio de los desafíos de tratar la enfermedad de Chagas en sus distintas fases y los abordajes actuales para nuevos tratamientos. Los objetivos de este trabajo fueron los siguientes: en primer lugar, estudiar el contexto socio-económico en que existe esta enfermedad y las implicaciones de este contexto para el futuro de la investigación; en segundo lugar, aprender de los varios puntos de vista de investigación para nuevos tratamientos y su potencial aplicación en pacientes. Para ello, se empleó un metodología de forma cualitativa, centrada sobre entrevistas semi-estructuradas con profesionales en los campos de la investigación y de la medicina relacionados con el Chagas. También se utilizó literatura y fuentes relacionadas para construir el contexto histórico y actual del campo. Los resultados del este estudio señalaron que el desarrollo de tratamientos para la enfermedad de Chagas está complicado tanto por aspectos científicos como aspectos sociales. Por ahora, los medicamentos existentes funcionan suficientemente bien, pero también tienen restricciones en su aplicación, las cuales hacen necesario la búsqueda de tratamientos que podrían ser aplicados más ampliamente. \ More than one hundred years after the discovery of Chagas, this neglected disease continues to affect more than six million people in Latin America, of which 1.5 million can be found in Argentina. To this day, there are only two medications to treat this disease. This project is based on an exploratory study of the challenges of treating Chagas disease in its distinct phases and the current approaches to new treatments. The objectives of this study include the following: firstly, to study the socio-economic context in which this disease exists, and the implications of this context for the future of research; secondly, to learn from the various viewpoints of new treatment research and its potential application in patients. To accomplish these objectives, this project used a qualitative methodology, focusing on semi-structured interviews with professionals in the fields of research and medicine related to Chagas. Additionally, literature and related sources were utilized to construct the historical and current context of the field. The results of this study indicated that the development of treatments for Chagas disease is complicated due to challenges both scientific and social. For now, the existing medications work sufficiently well, but have restrictions to their application, which makes it necessary to search for treatments that can be more widely applicabl