7 research outputs found

    A 3D MR-acquisition scheme for nonrigid bulk motion correction in simultaneous PET-MR.

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    PURPOSE: Positron emission tomography (PET) is a highly sensitive medical imaging technique commonly used to detect and assess tumor lesions. Magnetic resonance imaging (MRI) provides high resolution anatomical images with different contrasts and a range of additional information important for cancer diagnosis. Recently, simultaneous PET-MR systems have been released with the promise to provide complementary information from both modalities in a single examination. Due to long scan times, subject nonrigid bulk motion, i.e., changes of the patient's position on the scanner table leading to nonrigid changes of the patient's anatomy, during data acquisition can negatively impair image quality and tracer uptake quantification. A 3D MR-acquisition scheme is proposed to detect and correct for nonrigid bulk motion in simultaneously acquired PET-MR data. METHODS: A respiratory navigated three dimensional (3D) MR-acquisition with Radial Phase Encoding (RPE) is used to obtain T1- and T2-weighted data with an isotropic resolution of 1.5 mm. Healthy volunteers are asked to move the abdomen two to three times during data acquisition resulting in overall 19 movements at arbitrary time points. The acquisition scheme is used to retrospectively reconstruct dynamic 3D MR images with different temporal resolutions. Nonrigid bulk motion is detected and corrected in this image data. A simultaneous PET acquisition is simulated and the effect of motion correction is assessed on image quality and standardized uptake values (SUV) for lesions with different diameters. RESULTS: Six respiratory gated 3D data sets with T1- and T2-weighted contrast have been obtained in healthy volunteers. All bulk motion shifts have successfully been detected and motion fields describing the transformation between the different motion states could be obtained with an accuracy of 1.71 ± 0.29 mm. The PET simulation showed errors of up to 67% in measured SUV due to bulk motion which could be reduced to less than 10% with the proposed motion compensation approach. CONCLUSIONS: A MR acquisition scheme which yields both high resolution 3D anatomical data and highly accurate nonrigid motion information without an increase in scan time is presented. The proposed method leads to a strong improvement in both MR and PET image quality and ensures an accurate assessment of tracer uptake

    Prevalence, symptoms and management of uterine fibroids: an international internet-based survey of 21,746 women

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    <p>Abstract</p> <p>Background</p> <p>In 2009 the Uterine Bleeding and Pain Women's Research Study (UBP-WRS) was conducted interviewing 21,479 women across 8 countries in order to gain patient-based prevalence data on uterine pain and bleeding indications and investigate uterine symptoms and women's treatment experiences. This article shows relevant results of the study for the indication uterine fibroids providing data on self-reported prevalence, symptomatology and management of uterine fibroids.</p> <p>Methods</p> <p>2,500 women (USA: 4,500 women) in each country (Brazil, Canada, France, Germany, Italy, South Korea, the UK, the USA) completed an online survey. Women included were in their reproductive age (age group 15-49 years; USA: 18-49 years) and had ever experienced menstrual bleedings. Quotas were applied for age, region, level of education and household income of respondents. Variables have been analyzed descriptively and exploratory statistical tests have been performed.</p> <p>Results</p> <p>The self-reported prevalence of uterine fibroids ranged from 4.5% (UK) to 9.8% (Italy), reaching 9.4% (UK) to 17.8% (Italy) in the age group of 40-49 years. Women with a diagnosis of uterine fibroids reported significantly more often about bleeding symptoms than women without a diagnosis: heavy bleedings (59.8% vs. 37.4%), prolonged bleedings (37.3% vs. 15.6%), bleeding between periods (33.3% vs. 13.5%), frequent periods (28.4% vs. 15.2%), irregular and predictable periods (36.3% vs. 23.9%). Furthermore women with diagnosed uterine fibroids reported significantly more often about the following pain symptoms: pressure on the bladder (32.6% vs. 15.0%), chronic pelvic pain (14.5% vs. 2.9%), painful sexual intercourse (23.5% vs. 9.1%) and pain occurring mid-cycle, after and during menstrual bleeding (31.3%, 16.7%, 59.7%, vs. 17.1%, 6.4%, 52.0%). 53.7% of women reported that their symptoms had a negative impact on their life in the last 12 month, influencing their sexual life (42.9%), performance at work (27.7%) and relationship & family (27.2%).</p> <p>Conclusions</p> <p>Uterine fibroid is a common concern in women at fertile age causing multiple bleeding and pain symptoms which can have a negative impact on different aspects in women's life.</p

    Development of an Alternative Test System for Chronic Testing of Lotic Macroinvertebrate Species: A Case Study with the Insecticide Imidacloprid

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    There are currently few suitable test systems for the chronic toxicity testing of aquatic macroinvertebrates under stream conditions. Therefore, a new test system mimicking running water conditions was developed for testing with lotic insects. This system uses small test cages, with 10 of these suspended inside each 25‐L container and rotating at 0.1 m/s, to create a water flow for the individual organism inside each cage. To test the performance of the new exposure system, chronic effects (21 d) of the neonicotinoid imidacloprid were investigated with field‐collected larvae of the stonefly Protonemura sp. Endpoints were survival, growth, and/or emergence (depending on the developmental stage of the larvae at the start of the exposure). Two experiments conducted 1 yr apart showed good reproducibility: growth 10% effect concentration (EC10) values were 15.3 and 18.5 μg/L and no‐observed‐effect concentration (NOEC) values were 30.3 and 21.5 μg/L. A third experiment, performed with further‐developed larval instars, showed a significant effect of imidacloprid on emergence (with EC10 of 5.97 μg/L and NOEC of 2.89 μg/L) and a significant effect on survival (with median lethal concentration of 44.7 µg/L). The results of the present study show that the newly developed test system provides a suitable approach for toxicity testing with stonefly larvae and potentially for other lotic macroinvertebrate species. Environ Toxicol Chem 2021;40:2229–2239. © 2021 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC

    Alarmin S100A8/S100A9 as a biomarker for molecular imaging of local inflammatory activity

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    Inflammation has a key role in the pathogenesis of various human diseases. The early detection, localization and monitoring of inflammation are crucial for tailoring individual therapies. However, reliable biomarkers to detect local inflammatory activities and to predict disease outcome are still missing. Alarmins, which are locally released during cellular stress, are early amplifiers of inflammation. Here, using optical molecular imaging, we demonstrate that the alarmin S100A8/S100A9 serves as a sensitive local and systemic marker for the detection of even sub-clinical disease activity in inflammatory and immunological processes like irritative and allergic contact dermatitis. In a model of collagen-induced arthritis, we use S100A8/S100A9 imaging to predict the development of disease activity. Furthermore, S100A8/S100A9 can act as a very early and sensitive biomarker in experimental leishmaniasis for phagocyte activation linked to an effective Th1-response. In conclusion, the alarmin S100A8/S100A9 is a valuable and sensitive molecular target for novel imaging approaches to monitor clinically relevant inflammatory disorders on a molecular level

    Interim FDG-PET analysis to identify patients with aggressive non-Hodgkin lymphoma who benefit from treatment intensification: a post-hoc analysis of the PETAL trial

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    The randomized PETAL trial failed to demonstrate a benefit of interim FDG-PET (iPET)-based treatment intensification over continued standard therapy with CHOP (plus rituximab (R) in CD20-positive lymphomas). We hypothesized that PET analysis of all lymphoma manifestations may identify patients who benefitted from treatment intensification. A previously developed neural network was employed for iPET analysis to identify the highest pathological FDG uptake (max-SUVAI) and the mean FDG uptake of all lymphoma manifestations (mean-SUVAI). High mean-SUVAI uptake was determined separately for iPET-positive and iPET-negative patients. The endpoint was time-to-progression (TTP). There was a significant interaction of additional rituximab and mean-SUVAI in the iPET-negative group (HR = 0.6, p < 0.05). Patients with high mean-SUVAI had significantly prolonged TTP when treated with 6xR-CHOP + 2 R (not reached versus 52 months, p < 0.05), whereas max-SUVmanual failed to show an impact of additional rituximab. In the iPET-positive group, patients with high mean-SUVAI had a significantly longer TTP with (R-)CHOP than with the Burkitt protocol (14 versus 4 months, p < 0.01). Comprehensive iPET evaluation may provide new prognosticators in aggressive lymphoma. Additional application of rituximab was associated with prolonged TTP in iPET-negative patients with high mean-SUVAI. Comprehensive iPET interpretation could identify high-risk patients who benefit from study-specific interventions

    Chronic thromboembolic pulmonary hypertension (CTEPH): Updated Recommendations from the Cologne Consensus Conference 2018

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    Chronic thromboembolic pulmonary hypertension (CTEPH) is a subgroup of pulmonary hypertension that differs fromall other forms of PHin terms of its pathophysiology, patient characteristics and treatment. For implementation of the European Guidelines on Diagnosis and Treatment of Pulmonary Hypertension in Germany, the Cologne Consensus Conference 2016 was held and last updated in spring of 2018. One of the working groups was dedicated to CTEPH, practical and controversial issues were commented and updated. In every patient with suspected PH, CTEPH or chronic thromboembolic disease (CTED, i.e. symptomatic residual vasculopathy without pulmonary hypertension) should be excluded. Primary treatment is surgical pulmonary endarterectomy (PEA) in a multidisciplinary CTEPH centre. Inoperable patients or patients with persistent or recurrent CTEPH after PEA are candidates for targeted drug therapy. There is increasing experience with balloon pulmonary angioplasty (BPA) for inoperable patients; this option, like PEA, is reserved for specialised centres with expertise in this treatment method. (c) 2018 Published by Elsevier B.V
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