Design for a coherent-scatter imaging system compatible with screening mammography.
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ABSTRACT:
SUBMITTER: Kern K
PROVIDER: S-EPMC4999495 | biostudies-other | 2016 Jul
REPOSITORIES: biostudies-other
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Project description:Conventional mammography can suffer from poor contrast between healthy and cancerous tissues due to the small difference in attenuation properties. Coherent scatter slot scan imaging is an imaging technique which provides additional information and is compatible with conventional mammography. A Monte Carlo simulation of coherent scatter slot scan imaging was performed to assess its performance and provide system optimization. Coherent scatter could be exploited using a system similar to conventional slot scan mammography system with antiscatter grids tilted at the characteristic angle of cancerous tissues. System optimization was performed across several parameters, including source voltage, tilt angle, grid distances, grid ratio, and shielding geometry. The simulated carcinomas were detectable for tumors as small as 5 mm in diameter, so coherent scatter analysis using a wide-slot setup could be promising as an enhancement for screening mammography. Employing coherent scatter information simultaneously with conventional mammography could yield a conventional high spatial resolution image with additional coherent scatter information.
| S-EPMC4999523 | biostudies-other
Project description:BackgroundBreast cancer is the most common cancer and the leading cause of death among Latinas in the United States. The Multi-level Intervention to Increase Participation in Mammography Screening study (¡Fortaleza Latina!) is a partnership among research institutions, a Latino-serving community-based primary care clinic organization, and a cancer treatment center. The study will assess the efficacy of a clinic- and patient-level program to increase breast cancer screening among Latinas in Western Washington.Methods/designThe intervention is a multi-level breast cancer screening program in four participating primary care clinics. The study is a parallel randomized controlled trial of 600 Latino women aged 42-74 who are non-compliant with breast cancer screening guidelines. Participants will be randomized within clinic using block randomization to: (1) a control arm (usual care); and (2) a theory-based counseling program consisting of a 'promotora' or community health worker-led home-based intervention to encourage breast cancer screening. At the clinic-level, two clinics will offer additional mammography services provided by a mobile mammography unit operated by the Seattle Cancer Care Alliance. The primary endpoint is the rate of mammography uptake over the 1-year follow-up period.DiscussionThis multi-level intervention aims to raise rates of participation in breast cancer screening among Latino women. If effective, the program may improve rates of early detection of breast cancer in Latino women. Clinicaltrials.govRegistration numberNCT02010008.
| S-EPMC9629029 | biostudies-literature
Project description:We present a novel approach to coherent photonic THz systems supporting complex modulation. The proposed scheme uses a single optical path avoiding the problems of current implementations, which include: phase decorrelation, 3-dB power loss, and polarization and power matching circuits. More importantly, we show that our novel approach is compatible with direct modulation of the output of an optical frequency comb (i.e., not requiring the demultiplexing of two tones from the comb), further simplifying the system and enabling an increase in the transmitted RF power for a fixed average optical power injected into the photodiode.
| S-EPMC9184747 | biostudies-literature
Project description:PURPOSE:To assess the association between geographic access to mammography facilities and women's mammography utilization frequency. METHODS:Using data from the population-based 1995-2007 Wisconsin Women's Health study, we used proportional odds and logistic regression to test whether driving times to mammography facilities and the number of mammography facilities within 10 km of women's homes were associated with mammography frequency among women aged 50-74 years and whether associations differed between Rural-Urban Commuting Areas and income and education groups. RESULTS:We found evidence for nonlinear relationships between geographic access and mammography utilization (nonlinear effects of driving times and facility density, P-values .01 and .005, respectively). Having at least one nearby mammography facility was associated with greater mammography frequency among urban women (1 vs. 0 facilities, odds ratio 1.26, 95% confidence interval, 1.09-1.47), with similar effects among rural women. Adding more facilities had decreasing marginal effects. Long driving times tended to be associated with lower mammography frequency. We found no effect modification by income, education, or urbanicity. In rural settings, mammography nonuse was higher, facility density smaller, and driving times to facilities were longer. CONCLUSIONS:Having at least one mammography facility near one's home may increase mammography utilization, with decreasing effects per each additional facility.
| S-EPMC5819606 | biostudies-literature
Project description:Introduction: Since 2008 the German Mammography Screening Programme has been available throughout Germany to all women aged between 50 and 69. The programme strictly follows the European Guidelines. There are controversial discussions in the media as well as in the specialised press. Materials and Methods: Overview of the available data with regard to an evaluation of randomised studies and with regard to quality-assured screening programmes in accordance with EU Guidelines (including data from 18 screening countries). Results: Positive effects of screening: reduction in mortality, less invasive treatment. Negative effects: False-positive diagnoses and biopsy recommendations, so-called overdiagnoses, radiation dose. Limits of screening: Interval carcinomas, incomplete reduction in mortality. A mathematical synopsis of the latest publications from the European screening programmes with the diagnosis rates in Germany determined from >?4.6 million screening examinations produces the following: a total of 10?000 mammograms are created for 1000 women (P) taking part in the Mammography Screening Programme (each of whom undergoes 10 mammograms in 20 years). Overall, the risk of triggering breast cancer through a mammogram is very clearly below the annual natural risk of suffering from breast cancer. In the German screening, of these 1000 women, an average of 288 women are called back once in 20 years as a result of changes that are ultimately benign (<?3?% per cycle). Of these, 74 of the 288 women undergo a biopsy due to a benign change (false-positive biopsy recommendations, usually punch or vacuum biopsies). According to EUROSCREEN, 71 carcinomas develop among participants (56 are discovered in the screening, 15 in the interval), and 67 carcinomas among non-participants (N-P) (in some cases, several years later) during this period. The 4 additional diagnoses among the Ps are referred to as overdiagnoses, as they do not contribute to a reduction in mortality (these participants die beforehand from other causes of death). With regard to the carcinomas that concern the screening periods, 11 women out of 1000 die among the Ps; there are 19 deaths among the N-Ps (within the observation period plus follow-up period). Discussion: The false-positive rate is unavoidable, but is far lower with mammography screening than with other methods. Overdiagnoses are to be expected with any early detection. All calculations require assumptions and are therefore highly discrepant. They have very low evidence levels. The radiation dose should not be an argument against screening when applied correctly due to the very low risk and significant benefits. Interval carcinomas indicate the limits of a mammography screening programme. False-negatives only represent a subset of the interval carcinomas and are not to be equated with them. There is a very high evidence level for a significant reduction in mortality through mammography screening. For the first time, an independent expert commission has confirmed the results of the randomised studies and the statement of the WHO from 2002 and their further validity. Participants can expect a reduction in mortality of 30?%. Data from the current European screening programmes confirm a mortality reduction of 43?%, corresponding to 8/19 saved lives among 71 women with breast cancer or 1000 asymptomatic Ps. Many additional Ps benefit from less invasive treatment due to the early detection. Conclusions: As a result of the risk/benefit ratio, mammography screening should absolutely be recommended to asymptomatic women aged between 50-69. High importance is given to the provision of education for women by the treating gynaecologists as regards the opportunities for quality-assured early detection available to them in the healthcare system.
| S-EPMC3862045 | biostudies-literature
Project description:To introduce the development of the first magnetic resonance imaging (MRI)-compatible robotic system capable of automated brachytherapy seed placement.An MRI-compatible robotic system was conceptualized and manufactured. The entire robot was built of nonmagnetic and dielectric materials. The key technology of the system is a unique pneumatic motor that was specifically developed for this application. Various preclinical experiments were performed to test the robot for precision and imager compatibility.The robot was fully operational within all closed-bore MRI scanners. Compatibility tests in scanners of up to 7 Tesla field intensity showed no interference of the robot with the imager. Precision tests in tissue mockups yielded a mean seed placement error of 0.72 +/- 0.36 mm.The robotic system is fully MRI compatible. The new technology allows for automated and highly accurate operation within MRI scanners and does not deteriorate the MRI quality. We believe that this robot may become a useful instrument for image-guided prostate interventions.
| S-EPMC3100553 | biostudies-literature
Project description:Research and discovery of novel radiopharmaceuticals and targets thereof generally involves initial studies in cell cultures, followed by animal studies, both of which present several inherent limitations. The objective of this work was to develop a tissue bioreactor (TBR) enabling modulation of the microenvironment and to integrate the TBR with a small-animal PET scanner to facilitate imaging biomarker research and discovery and validation of radiopharmaceuticals.The TBR chamber is a custom-blown, water-jacketed, glass vessel enclosed in a circulating perfusion bath powered by a peristaltic pump, which is integrated within the field of view of the PET scanner. The chamber is in series with a gas exchanger and a vessel for degassing the system during filling. Dissolved oxygen/temperature probes and septa for injection or sampling are located at the inlet and outlet of the cell chamber. A pH probe is located at the chamber outlet. Effluent is collected in the fraction collector as mixed-cup samples. In addition, both medium and tissue chamber can be sampled to investigate tissue and secretory products through multiscale analysis. As a proof of concept, we studied the effects of lipids on glucose uptake using HepG2 cells. To that end, we varied the nutrient substrate environment over a period of approximately 27 d, before and after the addition of lipids, and studied the effects of pioglitazone, a peroxisome proliferator-activated receptor ? agonist, on lipid and glucose uptake. In parallel, the TBR was imaged by PET in conjunction with (11)C-palmitate in the presence and absence of lipids to characterize (11)C-palmitate uptake.The O2 consumption, glucose consumption, lactate production, and free fatty acid consumption and production rates were consistent in demonstrating the effects of lipids on glucose uptake. Pioglitazone exhibited improved glucose uptake within 3 d of treatment. Semiquantitative analysis suggested that lipids induced greater (11)C-palmitate uptake.The integrated TBR offers a platform to monitor and modulate the tissue microenvironment, thus facilitating tissue-specific imaging and therapeutic biomarkers of disease, identification of molecular diagnostic markers, and validation of radiopharmaceuticals in both rodent and human cell lines.
| S-EPMC3971724 | biostudies-literature
Project description:PurposeTo evaluate the clinical effectiveness and cost-effectiveness of screening strategies in which MR imaging and screen-film mammography were used, alone and in combination, in women with BRCA1 mutations.Materials and methodsBecause this study did not involve primary data collection from individual patients, institutional review board approval was not needed. By using a simulation model, we compared three annual screening strategies for a cohort of 25-year-old BRCA1 mutation carriers, as follows: (a) screen-film mammography, (b) MR imaging, and (c) combined MR imaging and screen-film mammography (combined screening). The model was used to estimate quality-adjusted life-years (QALYs) and lifetime costs. Incremental cost-effectiveness ratios were calculated. Input parameters were obtained from the medical literature, existing databases, and calibration. Costs (2007 U.S. dollars) and quality-of-life adjustments were derived from Medicare reimbursement rates and the medical literature. Sensitivity analysis was performed to evaluate the effect of uncertainty in parameter estimates on model results.ResultsIn the base-case analysis, annual combined screening was most effective (44.62 QALYs), and had the highest cost ($110973), followed by annual MR imaging alone (44.50 QALYs, $108641), and annual mammography alone (44.46 QALYs, $100336). Adding annual MR imaging to annual mammographic screening cost $69125 for each additional QALY gained. Sensitivity analysis indicated that, when the screening MR imaging cost increased to $960 (base case, $577), or breast cancer risk by age 70 years decreased below 58% (base case, 65%), or the sensitivity of combined screening decreased below 76% (base case, 94%), the cost of adding MR imaging to mammography exceeded $100000 per QALY.ConclusionAnnual combined screening provides the greatest life expectancy and is likely cost-effective when the value placed on gaining an additional QALY is in the range of $50000-$100000.Supplemental materialhttp://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.09091086/-/DC1.
| S-EPMC2826703 | biostudies-literature
Project description:BackgroundIn Germany, all women aged 50-69 have been invited to biennial mammography screening since 2009. We aimed to assess longitudinal adherence over ten years in women aged 50 in 2009 and characterize the different adherence groups.MethodsUsing the German Pharmacoepidemiological Research Database (GePaRD, ~ 20% of the German population), we included women aged 50 in 2009 (baseline) with continuous health insurance coverage and without breast cancer or in-situ-carcinoma. We followed them until age 59 and categorized them according to mammography screening participation into the following groups: never, 1-2, 3-4, 5-6 times. We characterized these groups, inter alia, regarding the use of other preventive measures, non-screening mammography (i.e., mammography outside the organized screening program) and menopausal hormone therapy.ResultsOverall, 82,666 women were included. Of these, 27.6% never participated in the screening program, 15.1% participated 1-2 times, 31.7% participated 3-4 times and 25.6% participated regularly (5-6 times). Among regular participants, 91% utilized other preventive measures (e.g., cervical cancer screening, general health checkup) before baseline as compared to 66% among non-participants. Menopausal hormone therapy was least common among non-participants (11% vs. 18% among regular participants). Among non-participants, the proportions using ≥ 1, ≥ 2, and ≥ 3 non-screening mammographies between age 50-59 were 25%, 18%, and 15%, respectively.ConclusionsUsing a large cohort based on claims data, this study provides novel insights into longitudinal adherence to the mammography screening program and the use of mammography outside of the program in Germany. Between age 50-59, 57% of eligible women participated at least three times in the German mammography screening program and 28% (~ 3 in 10 women) never participated. Among non-participants, 15% had at least three non-screening mammographies during this period, indicating potential gray screening. Participants more often utilized other preventive measures as compared to non-participants.
| S-EPMC10469853 | biostudies-literature
Project description:Despite the demonstrated need to increase screening mammography utilization and strong evidence that mail and telephone outreach to women can increase screening, most managed care organizations have not adopted comprehensive outreach programs. The uncertainty about optimum strategies and cost effectiveness have retarded widespread acceptance. While 70% of women report getting a mammogram within the prior 2 years, repeat mammography rates are less than 50%. This 5-year study is conducted though a Central Massachusetts healthcare plan and affiliated clinic. All women have adequate health insurance to cover the test.This randomized study compares 3 arms: reminder letter alone; reminder letter plus reminder call; reminder letter plus a second reminder and booklet plus a counselor call. All calls provide women with the opportunity to schedule a mammogram in a reasonable time. The invention period will span 4 years and include repeat attempts. The counselor arm is designed to educate, motivate and counsel women in an effort to alleviate PCP burden.All women who have been in the healthcare plan for 24 months and who have a current primary care provider (PCP) and who are aged 51-84 are randomized to 1 of 3 arms. Interventions are limited to women who become ? 18 months from a prior mammogram. Women and their physicians may opt out of the intervention study.Measurement of completed mammograms will use plan billing records and clinic electronic records. The primary outcome is the proportion of women continuously enrolled for ? 24 months who have had ? 1 mammogram in the last 24 months. Secondary outcomes include the number of women who need repeat interventions. The cost effectiveness analysis will measure all costs from the provider perspective.So far, 18,509 women aged 51-84 have been enrolled into our tracking database and were randomized into one of three arms. At baseline, 5,223 women were eligible for an intervention. We anticipate that the outcome will provide firm data about the maximal effectiveness as well as the cost effectiveness of the interventions both for increasing the mammography rate and the repeat mammography rate.http://clinicaltrials.gov/NCT01332032.
| S-EPMC3133545 | biostudies-literature