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

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

Crossing Divides: New Common Ground on Poverty and Economic Security

Crossing Divides: New Common Ground on Poverty and Economic Securit

Computer-assisted polyp matching between optical colonoscopy and CT colonography: a phantom study

Potentially precancerous polyps detected with CT colonography (CTC) need to be removed subsequently, using an optical colonoscope (OC). Due to large colonic deformations induced by the colonoscope, even very experienced colonoscopists find it difficult to pinpoint the exact location of the colonoscope tip in relation to polyps reported on CTC. This can cause unduly prolonged OC examinations that are stressful for the patient, colonoscopist and supporting staff. We developed a method, based on monocular 3D reconstruction from OC images, that automatically matches polyps observed in OC with polyps reported on prior CTC. A matching cost is computed, using rigid point-based registration between surface point clouds extracted from both modalities. A 3D printed and painted phantom of a 25 cm long transverse colon segment was used to validate the method on two medium sized polyps. Results indicate that the matching cost is smaller at the correct corresponding polyp between OC and CTC: the value is 3.9 times higher at the incorrect polyp, comparing the correct match between polyps to the incorrect match. Furthermore, we evaluate the matching of the reconstructed polyp from OC with other colonic endoluminal surface structures such as haustral folds and show that there is a minimum at the correct polyp from CTC. Automated matching between polyps observed at OC and prior CTC would facilitate the biopsy or removal of true-positive pathology or exclusion of false-positive CTC findings, and would reduce colonoscopy false-negative (missed) polyps. Ultimately, such a method might reduce healthcare costs, patient inconvenience and discomfort.Comment: This paper was presented at the SPIE Medical Imaging 2014 conferenc

Spectral imaging of thermal damage induced during microwave ablation in the liver

Induction of thermal damage to tissue through delivery of microwave energy is frequently applied in surgery to destroy diseased tissue such as cancer cells. Minimization of unwanted harm to healthy tissue is still achieved subjectively, and the surgeon has few tools at their disposal to monitor the spread of the induced damage. This work describes the use of optical methods to monitor the time course of changes to the tissue during delivery of microwave energy in the porcine liver. Multispectral imaging and diffuse reflectance spectroscopy are used to monitor temporal changes in optical properties in parallel with thermal imaging. The results demonstrate the ability to monitor the spatial extent of thermal damage on a whole organ, including possible secondary effects due to vascular damage. Future applications of this type of imaging may see the multispectral data used as a feedback mechanism to avoid collateral damage to critical healthy structures and to potentially verify sufficient application of energy to the diseased tissue.Comment: 4pg,6fig. Copyright 2018 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other work

Electromyographic Analysis of Shoulder Girdle Muscles during Common Internal Rotation Exercises

Background: High level throwing performance requires the development of effective muscle activation within shoulder girdle muscles particularly during forceful internal rotation (IR) motions. Study Design: Controlled Laboratory Descriptive Study Purpose: To investigate activation pattern of 16 shoulder girdle muscles/muscle sub-regions during three common shoulder IR exercises. Method: EMG was recorded in 30 healthy subjects from 16 shoulder girdle muscles/muscle sub-regions (surface electrode: anterior, middle and posterior deltoid, upper, middle and lower trapezius, serratus anterior, teres major, upper and lower latissimus dorsi, upper and lower pectoralis major; fine wire electrodes: supraspinatus, infraspinatus, subscapularis and rhomboid major) using a telemetric EMG system. Three IR exercises (standing IR at 0o and 90o of Abduction, and IR at Zero-Position) were studied. EMG amplitudes were normalized to EMGmax (EMG at maximal IR force in a standard position) and compared using one-way repeated-measures analysis of variance (ANOVA). Results: There were significant differences in muscles’ activation across IR exercises (p<0.05–p<0.001). Rotator cuff and deltoid muscles were highly activated during IR at 90° of Abduction. Latissimus dorsi exhibited markedly higher activation during IR at Zero-Position. While upper trapezius had the highest activation during IR at Zero-Position, middle and lower trapezius were activated at highest during IR at 90o of Abduction. The highest activation of serratus anterior and rhomboid major occurred in IR at Zero-Position and IR at 90o of Abduction, respectively. Conclusions: Studied exercises have the potential to effectively activate glenohumeral and scapular muscles involved in throwing motions. Results provide further evidence for developing rehabilitation, injury prevention, and training strategies

Convective infux/glymphatic system: tracers injected into the CSF enter and leave the brain along separate periarterial basement membrane pathways

Tracers injected into CSF pass into the brain alongside arteries and out again. This has been recently termed the "glymphatic system" that proposes tracers enter the brain along periarterial "spaces" and leave the brain along the walls of veins. The object of the present study is to test the hypothesis that: (1) tracers from the CSF enter the cerebral cortex along pial-glial basement membranes as there are no perivascular "spaces" around cortical arteries, (2) tracers leave the brain along smooth muscle cell basement membranes that form the Intramural Peri-Arterial Drainage (IPAD) pathways for the elimination of interstitial fluid and solutes from the brain. 2 μL of 100 μM soluble, fluorescent fixable amyloid β (Aβ) were injected into the CSF of the cisterna magna of 6-10 and 24-30 month-old male mice and their brains were examined 5 and 30 min later. At 5 min, immunocytochemistry and confocal microscopy revealed Aβ on the outer aspects of cortical arteries colocalized with α-2 laminin in the pial-glial basement membranes. At 30 min, Aβ was colocalised with collagen IV in smooth muscle cell basement membranes in the walls of cortical arteries corresponding to the IPAD pathways. No evidence for drainage along the walls of veins was found. Measurements of the depth of penetration of tracer were taken from 11 regions of the brain. Maximum depths of penetration of tracer into the brain were achieved in the pons and caudoputamen. Conclusions drawn from the present study are that tracers injected into the CSF enter and leave the brain along separate periarterial basement membrane pathways. The exit route is along IPAD pathways in which Aβ accumulates in cerebral amyloid angiopathy (CAA) in Alzheimer's disease. Results from this study suggest that CSF may be a suitable route for delivery of therapies for neurological diseases, including CAA

Meteor light curves: the relevant parameters

We investigate a uniform sample of 113 light curves (LCs) of meteors collected at the Wise Observatory in November 2002 while observing the Leonid meteor shower. We use previously defined descriptors such as the skewness F and a recently defined pointedness parameter along with a number of other measurable or derived quantities to explore the parameter space in search of meaningful LC descriptors. We make extensive use of statistical techniques to reveal links among the variables and to understand their relative importance. In particular, we show that meteors with long-duration trails rise slowly to their maximal brightness and also decay slowly from there while showing milder flaring than other meteors. Early skewed LCs show a fast rise to the peak. We show that the duration of te luminous phase of the meteor is th emost important variable differentiating among the 2002 LCs. The skewness parameter F appears only as the 2nd or 3rd in explaining the LC variance. We suggest that the pointedness parameter P could possibly be useful to discriminate among meteors from different showers, or to compare observations and model predictions.Comment: 10 pages (2 figures) in press with MNRA

CANPART : a research proposal concerning increased canadian citizens' participation in Habitat : the United Nations Conference on Human Settlements

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It takes patience and persistence to get negative feedback from patients

Background: Patient experience surveys are increasingly used to gain information about the quality of healthcare. This paper investigates whether patients who respond early or late, and before and after reminders, to a large national survey of in-patient experience differ in systematic ways in how they evaluate the care they received. Methods: The English national in-patient survey of 2009 obtained data from just under 70,000 patients. We analyse their responses to the question “Overall, how did you rate the care you received” in relation to the time they took to respond and whether or not they had had a reminder, using statistical models designed to examine the length of time taken for an event to occur, known as “failure time regression models”. Results: 41 per cent of patients responded after the first questionnaire and 11 per cent after reminders. Those who were least positive in their evaluation of care replied on average 3.1 days later than the most positive. However, the main dividing line was between patients who responded to the initial mailing or to the reminders. Even controlling for other factors that influence the likelihood of an early response, those who respond after the initial mailing were more likely to be positive about the care they received. Conclusion: This study, using a large national dataset, shows that bias towards a positive evaluation of care could be introduced if the length of time that patients are allowed to respond is truncated or if reminders are omitted. Both patience (time) and persistence (reminders) are required to achieve unbiased results. Quality improvement efforts depend on having accurate data and negative evaluations are particularly valuable. The relevance of these findings for recent developments in patient evaluation and quality improvement are drawn out, as well as the implications for practitioners, managers and policy makers