Breast-conserving surgery accompanied by adjuvant radiotherapy is the standard of care for patients with early-stage breast cancer. However, re-excision is reported in 20-30 % of cases, largely because of close or involved tumor margins in the specimen. Several intraoperative tumor margin assessment techniques have been proposed to overcome this issue, however, none have been widely adopted.
View Article and Find Full Text PDFUnlabelled: Breast-conserving surgery (BCS) is commonly used for the treatment of early-stage breast cancer. Following BCS, approximately 20% to 30% of patients require reexcision because postoperative histopathology identifies cancer in the surgical margins of the excised specimen. Quantitative micro-elastography (QME) is an imaging technique that maps microscale tissue stiffness and has demonstrated a high diagnostic accuracy (96%) in detecting cancer in specimens excised during surgery.
View Article and Find Full Text PDFWe demonstrate a convolutional neural network (CNN) for multi-class breast tissue classification as adipose tissue, benign dense tissue, or malignant tissue, using multi-channel optical coherence tomography (OCT) and attenuation images, and a novel Matthews correlation coefficient (MCC)-based loss function that correlates more strongly with performance metrics than the commonly used cross-entropy loss. We hypothesized that using multi-channel images would increase tumor detection performance compared to using OCT alone. 5,804 images from 29 patients were used to fine-tune a pre-trained ResNet-18 network.
View Article and Find Full Text PDFBiomed Opt Express
March 2021
Intraoperative margin assessment is needed to reduce the re-excision rate of breast-conserving surgery. One possibility is optical palpation, a tactile imaging technique that maps stress (force applied across the tissue surface) as an indicator of tissue stiffness. Images (optical palpograms) are generated by compressing a transparent silicone layer on the tissue and measuring the layer deformation using optical coherence tomography (OCT).
View Article and Find Full Text PDFInadequate margins in breast-conserving surgery (BCS) are associated with an increased likelihood of local recurrence of breast cancer. Currently, approximately 20% of BCS patients require repeat surgery due to inadequate margins at the initial operation. Implementation of an accurate, intraoperative margin assessment tool may reduce this re-excision rate.
View Article and Find Full Text PDFEffective intraoperative tumor margin assessment is needed to reduce re-excision rates in breast-conserving surgery (BCS). Mapping the attenuation coefficient in optical coherence tomography (OCT) throughout a sample to create an image (attenuation imaging) is one promising approach. For the first time, three-dimensional OCT attenuation imaging of human breast tissue microarchitecture using a wide-field (up to ~45 × 45 × 3.
View Article and Find Full Text PDFCompression optical coherence elastography (OCE) typically requires a mechanical actuator to impart a controlled uniform strain to the sample. However, for handheld scanning, this adds complexity to the design of the probe and the actuator stroke limits the amount of strain that can be applied. In this work, we present a new volumetric imaging approach that utilizes bidirectional manual compression via the natural motion of the user's hand to induce strain to the sample, realizing compact, actuator-free, handheld compression OCE.
View Article and Find Full Text PDFOptical coherence elastography (OCE) has been proposed for a range of clinical applications. However, the majority of these studies have been performed using bulky, lab-based imaging systems. A compact, handheld imaging probe would accelerate clinical translation, however, to date, this had been inhibited by the slow scan rates of compact devices and the motion artifact induced by the user's hand.
View Article and Find Full Text PDFIt has been demonstrated that optical coherence micro-elastography (OCME) provides additional contrast of tumor compared to optical coherence tomography (OCT) alone. Previous studies, however, have predominantly been performed on mastectomy specimens. Such specimens typically differ substantially in composition and geometry from the more clinically relevant wide-local excision (WLE) specimens excised during breast-conserving surgery.
View Article and Find Full Text PDFHandheld imaging probes are needed to extend the clinical translation of optical elastography to applications, yet such probes have received little attention. In this paper, we present the first demonstration of optical palpation using a handheld probe. Optical palpation is a variant of optical elastography that uses three-dimensional optical coherence tomography (3D-OCT) to provide maps of stress at the tissue surface under static compression.
View Article and Find Full Text PDFObjectives: To i) describe the demographic and assault characteristics of males alleging recent sexual assault, ii) determine the severity and frequency of general body injury and the frequency of anal and genital injury, iii) identify vulnerability factors and assault characteristics associated with injury.
Design: Cross-sectional study.
Setting: Sexual Assault Resource Centre (SARC), Western Australia.
Currently, 20-30% of patients undergoing breast-conserving surgery require a second surgery due to insufficient surgical margins in the initial procedure. We have developed a wide-field quantitative micro-elastography system for the assessment of tumor margins. In this technique, we map tissue elasticity over a field-of-view of ~46 × 46 mm.
View Article and Find Full Text PDFObjectives: To describe the frequency and severity of general body injury in women alleging recent sexual assault and then identify demographic and assault characteristics associated with injury severity.
Design: Cross-sectional study.
Setting: Sexual Assault Resource Centre (SARC), Western Australia.
Background: The Sexual Assault Resource Center (SARC) in Perth, Western Australia provides free 24-hour medical, forensic, and counseling services to persons aged over 13 years following sexual assault.
Objective: The aim of this research was to design a data management system that maintains accurate quality information on all sexual assault cases referred to SARC, facilitating audit and peer-reviewed research.
Methods: The work to develop SARC Medical Services Clinical Information System (SARC-MSCIS) took place during 2007-2009 as a collaboration between SARC and Curtin University, Perth, Western Australia.
Objectives: To describe the frequency of genital and anal injury and associated demographic and assault characteristics in women alleging sexual assault.
Design: Cross-sectional study.
Setting: Sexual Assault Resource Centre (SARC), Western Australia.
Aims/hypothesis: The study aimed to assess the incidence, age of onset, survival and relative hazard of dementia in well-categorised community-based patients with type 2 diabetes compared with a matched cohort of individuals without diabetes.
Methods: A longitudinal observational study was undertaken involving 1291 participants with type 2 diabetes from the Fremantle Diabetes Study and 5159 matched residents without documented diabetes. Linkage with health-related databases was used to detect incident dementia.
Background: Acute myocardial infarction (AMI) incidence has been declining throughout the developed world. Australia has been an outlier to this trend, with AMI incidence reportedly increasing. This study provides a detailed investigation on the incidence of acute myocardial infarction (AMI) in Western Australia overall, and by age, sex, level of geographic remoteness and socioeconomic status.
View Article and Find Full Text PDFObjective: To describe the prevalence, risk factors, signs and symptoms of non-fatal strangulation (NFS) in women referred to a Sexual Assault Resource Centre (SARC) following recent sexual assault.
Methods: A cross-sectional study using data routinely collected at time of forensic examination of women (age ≥ 13 years) referred to the Western Australian SARC between Jan-2009 and Mar-2015 alleging a recent sexual assault. Data on demographics, assault characteristics and forensic findings were available.
Objective: Although prospective studies suggest light-to-moderate chronic alcohol intake protects against coronary artery disease in type 2 diabetic patients, the balance of effects on individual cardiovascular risk factors needs further assessment. We examined the effects of alcohol consumption on 24-h ambulatory blood pressure (BP) and heart rate (HR), high-density lipoprotein cholesterol, fibrinogen, C-reactive protein, homocysteine, and glycaemic control in well controlled type 2 diabetes.
Methods: Twenty-four participants aged 49-66 year were randomized to a three-period crossover study with women drinking red wine 230 ml/day (∼24 g alcohol/day) and men drinking red wine 300 ml/day (∼31 g alcohol/day), or equivalent volumes of dealcoholized red wine (DRW) or water, each for 4 weeks.
Objective: To examine the association of mid-life exposure to several psychiatric disorders with the development of late-life dementia.
Methods: A matched case-control study using Western Australian state-wide hospital inpatient, outpatient mental health and emergency records linked to death records. Incident dementia cases (2000-2009) aged 65 to 84 years were sex- and age-matched to an electoral roll control.
Background: The Australian Pharmaceutical Benefits Scheme (PBS) first subsidized cholinesterase inhibitors (CEIs) for Alzheimer's disease in 2001, introducing a novel therapy for a previously untreatable common condition. This study aims to determine Australian rates of CEI use and to assess equality of access to treatment based on socioeconomic status and geographic remoteness.
Methods: Pharmaceutical claims records were used to identify all Australians prescribed CEIs between January 2003 and December 2010.
Dementia-related healthcare planning requires accurate information on dementia patient characteristics and hospitalization trends at a population level. This population-based retrospective cohort study was designed to evaluate factors associated with total hospital length-of-stay (tLOS) in the last year of life (1990-2005) in Western Australians with dementia. Using linked hospital and death records, 29,884 dementia cases were identified.
View Article and Find Full Text PDFBackground/aim: To use health record data linkage to improve case ascertainment and death rate estimates of deaths with dementia.
Methods: Retrospective population study. Western Australians older than 20 years who died between 1990 and 2005 with a dementia diagnosis in Western Australian hospitals and/or death records using the Western Australian Data Linkage System were classed as having a lifetime history of dementia.
Our study investigated health service use for people in the last year of life, comparing those who died with and without Alzheimer's disease (AD) documented on the death certificate. Using a population-based retrospective cohort design, and utilizing the Western Australian Data Linkage System for the period 2000-2002 (2.5 years), the study found that 992 people died of either AD alone or AD with at least one other condition recorded on the death certificate.
View Article and Find Full Text PDFThere is considerable evidence that chronic moderate-to-high alcohol consumption increases blood pressure. The mechanisms by which this occurs are not clear. Alcohol consumption can induce oxidative stress and cytochrome P450 (CYP450) isoforms that are associated with oxidative stress and may influence vascular tone.
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