546 research outputs found
Polytomous diagnosis of ovarian tumors as benign, borderline, primary invasive or metastatic: development and validation of standard and kernel-based risk prediction models
No full text25.03.14 KB. Ok to add published version to spiral, OA pape
Common Book Author Kelsey Timmerman to Visit Campus
No full textOn Oct. 3, Timmerman will speak about his book at 8 p.m. in Byrnes Auditorium. It is a free cultural event and open to the public
Travels of Kelsey Timmerman Map
No full textThis map shows the countries visited by author Kelsey Timmerman for his book "Where Am I Wearing." The book details the garment production industry and the lives of its workers in factories around the world. The book was chosen as the freshman common reader for Ball State University for 2012
Students Experience Guatemala with Common Book Author Kelsey Timmerman
No full textStudents spent seven days in Guatemala, visiting fair trade cooperatives and coffee farmers and touring the area. Kelsey Timmerman wrote the 2012-13 Common Book, Where Am I Wearing
Long-term outcome and pre-interventional predictors for late intervention after uterine fibroid embolization
No full textOBJECTIVES: To assess the long-term freedom of surgical conversion after uterine fibroid embolization (UFE) and to define predictors for better clinical outcome. Additionally, the potential of pregnancy after UFE is assessed. STUDY DESIGN: Single-center retrospective cohort study including 190 patients who underwent UFE between 2001 and 2016. Data were obtained by postal questionnaire including symptom severity, late reintervention rate and post procedural fertility. Patient characteristics were extracted from the patients' electronic medical records. The cumulative rate of freedom from treatment failure was determined by Kaplan-Meier analysis. Cox regression models were used for univariate analyses of the association between patient preinterventional characteristics and late surgical conversion. Secondary outcome measures were patient specific predictors of treatment failure and evaluation of post-procedural fertility. RESULTS: Long-term follow-up was available for a median of 6.1 years (range 1.2-15.2 y) in 95 out of 190 patients (50 %). Freedom from treatment failure showed a cumulative rate of 72.9 % after 10 years and stable until end of follow-up. A 63.8 % reduction in symptoms and a 23.3% increase in quality of life was found. Significant increase of treatment failure was found in patients with increasing pre-interventional uterine volume (p = 0.0003) or dominant fibroid volume (p = 0.0042); 9 out of 23 patients (39.13 %) with child-bearing wish became pregnant and conceived one or more children after UFE. CONCLUSION: UFE is associated with sustained long-term symptom control. Larger size uterus or dominant fibroma are correlated with higher late surgical conversion rate. Last, women can become pregnant and deliver after UFE.status: Publishe
Ultrasound in female fertility investigation
No full textMen and women who desire children aim for a healthy offspring. For a woman, this means an ovulation, successful conception and transport of the zygote along the fallopian tube, implantation in the endometrial cavity, progress of the pregnancy to viability and a safe delivery resulting in a live born child in good health and happy parents. A fertility investigation aims primarily at identifying factors that may affect the couple’s chances for a successful conception and embryo implantation.
This work focuses on information concerning female fertility that is obtainable with ultrasonography.
With current ultrasound technology available in most gynecological offices and fertility centers, it is possible to obtain reliable and accurate information on many aspects of a woman’s reproductive organs: evaluation of ovulation (ovarian morphology), tubal transport (tubal patency testing), implantation (morphology of the uterus and in particular the uterine cavity, endometrium, endomyometrial junction and myometrium) and pelvic endometriosis. Moreover, an ultrasound examination is relatively cheap, easy to perform from a logistic point of view and not very time consuming, expensive nor invasive compared to other diagnostic modalities.
The study populations consist of prospective cohorts of consecutive women attending the Gynecological Ultrasound Unit (head Prof Dr D. Timmerman) of the Department of Obstetrics and Gynecology of the University Hospital Gasthuisberg in Leuven. The women were referred for targeted ultrasound evaluation of ovarian reserve/function, tubal patency, uterine cavity or endometriosis. Women included in this work were referred mostly by fertility specialists of the Leuven University Fertility Center (LUFC) (head: Prof Dr T. D’Hooghe; since 2016 Prof Dr C. Meuleman) or by gynecologists. The studies on contrast sonography of the uterine cavity (GIS) are part of the ‘bleeding clinic’ and the International Endometrial Tumor Analysis (IETA) project, both led by Dr T. Van den Bosch. The Clinical Data Miner (CDM) used for the inter- and intra-observer assessment studies is a KU Leuven project by Ir. A. Installé for web-based standardized data collection.
The first chapter recalls some basic principles of medical imaging by ultrasound. It is important to take into account the technical limitations of ultrasound imaging. In women of reproductive age, the point of time in the menstrual cycle and/or the use of hormonal preparations are relevant when interpreting ultrasound images. Inappropriate timing may lead to reduced accuracy, erroneous diagnosis or to inconclusive results necessitating a repeat ultrasound scan.
The second chapter is on reporting of ultrasound images. In reporting ultrasound findings, errors in communication can be avoided by using best practice initiatives on what to scan and how to report using standardized terms and definitions as proposed in the IOTA, IETA, and MUSA and IDEA consensus papers. It is equally important to specify the criteria used to define (ab)normality e.g. in CUA or PCOM.
An ultrasound examination in the fertility workup is a real-time 2D evaluation of uterine and ovarian morphology and of adnexal and pelvic pathology (e.g. hydrosalpinx, endometriosis). Additional information can be obtained with 3D volume ultrasound and the use of contrast agents.
3D volume ultrasound is particularly useful to assess ovarian and uterine morphology (chapter 3). Coronal images of the uterus are needed for accurate diagnosis of CUA and are useful to assess the uterine cavity (e.g. position of IUCD), endometrium (e.g. polyp) and myometrium (e.g. junctional zone). A 3D volume to assess the number, size and follicle distribution may be particularly useful in multifollicular ovaries. Specific software (e.g. automated volume count, inversed rendering) may reduce examination time, improve inter- and intra-observer agreement and thus reliability of the assessment and improve communication with the patient and with those involved in patient management. Off-line analysis can be used in quality assessment, teaching and training.
Contrast enhanced sonography is discussed in chapter 4. Anechoic contrast fluid instilled in the uterine cavity (FIS) improves the detection of congenital or acquired intracavitary lesions. Gel offers some practical advantages compared to saline. Hysterosalpingo-contrast-sonography (HyCoSy) is evaluation of tubal patency with ultrasound. An echogenic contrast agent such as gelfoam (HyFoSy) allows for accurate and reliable non-invasive screening and can replace HSG.
An ultrasound-based approach in female fertility investigation is suggested in chapter 5. TV ultrasound allows for accurate assessment of uterine morphology, intracavitary and myometrial lesions, ovarian function and tubal patency. Deep infiltrating pelvic endometriosis and adenomyosis can be detected and mapped and the depth of invasion can be estimated.
Finally, women should not be alarmed unnecessarily and/or be subjected to treatment because of ultrasound images only. The clinical relevance of ultrasound findings is to be ascertained and a risk benefit analysis is to be discussed with the patient before setting up treatment.status: Publishe
A new imaging technology to reduce the radiation dose during uterine fibroid embolization
No full textBackground Uterine fibroid embolization (UFE) is a minimally invasive imaging-guided treatment using radiation exposure. Purpose To compare the patients’ radiation exposure during UFE before and after introduction of a new X-ray imaging platform. Material and Methods Forty-one patients were enrolled in a prospective, comparative two-arm project before and after introduction of a new X-ray imaging platform with reduced dose settings, i.e. novel real-time image processing techniques (AlluraClarity). Demographic, pre-interventional imaging, and procedural data, including dose area product (DAP) and estimated organ dose on the ovaries and uterus, were recorded and angiographic quality of overall procedure was assessed. Results There were no significant differences in demographic characteristics and preoperative fibroid and uterine volumes in the two groups. The new imaging platform led to a significant reduction in mean total DAP (102 vs. 438 Gy.cm2; P < 0.001), mean fluoroscopy DAP (32 vs. 138 Gy.cm2; P < 0.001), mean acquisition DAP (70 vs. 300 Gy.cm2; P < 0.001), and acquisition DAP estimated organ dose in ovaries (42 vs. 118 mGy; P < 0.001) and uterus (40 vs. 118 mGy, P < 0.001), without impairment of the procedure and angiographic image quality. Conclusion A substantial 77% reduction of DAP values and 64% and 66% reduction in organ dose on ovaries and uterus, respectively, was demonstrated with the new imaging platform, while maintaining optimal imaging quality and efficacy. </jats:sec
Parution : Noel Clycq et al. (eds), Radicalisation. A Marginal Phenomenon or a Mirror to Society?, Leuven University Press, Febr. 2019
No full textRadicalisation A Marginal Phenomenon or a Mirror to Society? Edited by Noel Clycq, Christiane Timmerman, Dirk Vanheule, Rut Van Caudenberg, and Stiene Ravn Vital insights into the complex nature of the concept of radicalisationRadicalisation is a topical and a much-discussed concept in current European societies. Its use in policy and societal discourses, such as media coverage and educational contexts, is very sensitive. This thought-provoking collection of essays critically addresses ..
Taming instabilities in power grid networks by decentralized control
No full textRenewables will soon dominate energy production in our electric power system. And yet, how to integrate renewable energy into the grid and the market is still a subject of major debate. Decentral Smart Grid Control (DSGC) was recently proposed as a robust and decentralized approach to balance supply and demand and to guarantee a grid operation that is both economically and dynamically feasible. Here, we analyze the impact of network topology by assessing the stability of essential network motifs using both linear stability analysis and basin volume for delay systems. Our results indicate that if frequency measurements are averaged over sufficiently large time intervals, DSGC enhances the stability of extended power grid systems. We further investigate whether DSGC supports centralized and/or decentralized power production and find it to be applicable to both. However, our results on cycle-like systems suggest that DSGC favors systems with decentralized production. Here, lower line capacities and lower averaging times are required compared to those with centralized production
Ontwikkelen van evidence-based strategieën voor diagnostiek en klinischhandelen bij eierstoktumoren: resultaten van de International OvarianTumour Analysis (IOTA) studies
No full textWhilst patients with ovarian cancer clearly benefit from centralised, comprehensive care in dedicated cancer centres, unfortunately the majority of them still do not receive appropriate specialist treatment. Any improvement in the accuracy of current triaging and referral pathways whether using new imaging tests or biomarkers would therefore be of value in order to optimise the appropriate selection of patients for such care (Chapter 1).
An analysis of the current evidence shows that such diagnostic tests are now available, but still await recognition, acceptance and widespread adoption. It is therefore to be hoped that present guidance relating to the classification of ovarian masses will soon become more “evidence-based”. These include the International Ovarian Tumour Analysis (IOTA) LR2 risk prediction model and ultrasound-based IOTA Simple Rules (SR) (Chapter 2).
Based on a comprehensive recent meta-analysis both currently offer the optimal “evidence-based” approach to discriminating between cancer and benign conditions in women with adnexal tumours needing surgery (Chapter 3). The IOTA LR2 risk model and SR are reliable diagnostic tests having been shown to maintain a high sensitivity for cancer after independent external validation and both temporal and external validation by the IOTA group in the hands of examiners with various levels of ultrasound expertise (Chapter 4 and 5). Both diagnostic approaches also offer more accurate triage compared to the current standard of care diagnostic test Risk of Malignancy Index (RMI).
The development of the IOTA Assessment of Different NEoplasias in the AdneXa (ADNEX) multiclass risk prediction model represents an important step forward towards more individualised patient care in this area (Chapter 6). The ADNEX model is novel and enables the more specific subtyping of adnexal cancers (i.e. borderline tumours, stage 1 invasive ovarian cancer, stage II-IV invasive ovarian cancer, and secondary metastatic malignant tumours) and shares similar levels of accuracy to IOTA LR2 and SR for basic discrimination between cancer and benign disease. Its use has the potential to further improve and fine-tune management decisions and so reduce the morbidity and mortality associated with adnexal pathology.
Biomarkers are also attractive, popular and recommended tools to support clinical judgment of the nature of an adnexal mass. At present two novel commercial biomarkerbased algorithms have been developed in order to improve the poor accuracy of serum CA125; the Multivariate Index Assay and the ROMA algorithm. The latter utilises levels of CA125 and a new emerging epithelial biomarker human-epididymis-protein-4 (HE4) combined with the patient’s menopausal status to classify patients as at high or low risk for malignancy (Chapter 7). This test rapidly gained widespread attention, as evidenced by its numerous validation studies throughout the world. However, based on the findings of this thesis both commercial tests still seem redundant for preoperative diagnosis if good quality transvaginal ultrasonography (TVS) is available and the IOTA models are used in the correct manner (Chapter 3 and Chapter 7).
TVS is accepted as the most appropriate initial imaging investigation to identify and characterise any mass if present in women suspected of having adnexal pathology (chapter 8). Other imaging modalities such as computed-tomography (CT) and [18F]-fluorodeoxyglucose positron emission tomography ([18F]-FDG-PET) both lack accuracy for preoperative diagnosis and are more useful tools for staging of malignant disease and the assessment of ovarian cancer recurrence. Magnetic resonance imaging (MRI) may have a limited role to play in characterising so-called “difficult masses” after ultrasound review. The IOTA prediction models and rules offer new criteria that we can use to clearly define complex or “difficult to classify” adnexal masses to focus the role for second-line imaging tests such as conventional MRI combined with dynamic contrastenhanced (DCE) or diffusion-weighted (DWI) sequences on masses where further tests other than ultrasonography would be of value to minimise healthcare costs (Chapter 8).
The IOTA study has made significant progress in relation to the preoperative classification of adnexal masses, however what is now needed is to see if these or new diagnostic tools will have a positive influence on both clinical management and patient outcomes in true interventional studies; can assist clinicians to select patients with adnexal masses that are suitable for expectant management; and that will work in all health care settings (i.e. primary vs secondary vs tertiary care). The future agenda of the IOTA project will focus on these important themes (Chapter 9).status: Publishe
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