Beth Bjerregaard

Herlev Hospital, Herlev, Capital Region, Denmark

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Publications (31)38.92 Total impact

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    ABSTRACT: To determine the impact of comprehensiveness of cytology registration on the proportion of cervical cancer patients without a recent screening history. For Danish women diagnosed with cervical cancer in 2003-2007, we used cytology data from the nationwide Danish Pathology Data Bank and the National Health Service Register. In five steps, we included data from an increasing number of cervical screening laboratories into the analysis, and calculated the proportions of screened women who had cytology registered in two screening rounds prior to the cancer diagnosis. In total, 1867 cervical cancer patients were included in the analysis. When looking only at the screening history in the laboratory that diagnosed the cancer, it appeared that only 40% of women were screened in the last two rounds. This proportion increased to 55% when nationwide screening data were used. This corresponded to a 25% decrease in the proportion of patients without a recent screening history. The level of comprehensiveness of screening data makes a measurable difference when evaluating the screening histories of women with cervical cancer. It is important that actions for the improvement of a screening program are based on comprehensive cytology registrations.
    No preview · Article · Jan 2012 · Preventive Medicine
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    Beth Bjerregaard · Ole B Larsen
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    ABSTRACT: The National Board of Health, Denmark in 1997 published guidelines for reporting of pathology data and the Danish Pathology Register (DPR) was established. DPR contains patient, pathology, and workload data. All records are subject to error tracing. The DPR covers all pathology data in Denmark. The data is used by the pathologists in the daily diagnostic process. The National Board of Health uses the data in the Danish Cancer Registry and DPR is unique for research as data can be linked to tissue biobanks and clinical databases.
    Preview · Article · Jul 2011 · Scandinavian Journal of Public Health
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    ABSTRACT: Diagnostic histological and cytological specimens are routinely stored in pathology department archives. These biobanks are a valuable research resource for many diseases, particularly if they can be linked to high quality population-based health registries, allowing large retrospective epidemiological studies to be carried out. Such studies are of significant importance, for example in the search for novel prognostic and predictive biomarkers in the era of personalized medicine. Denmark has a wealth of highly-regarded population-based registries that are ideally suited to conduct this type of epidemiological research. We describe two recent additions to these databases: the Danish National Pathology Registry (DNPR) and its underlying national online registration database, the Danish Pathology Data Bank (DPDB). The DNPR and the DPDB contain detailed nationwide records of all pathology specimens analyzed in Denmark since 1997, and an incomplete but nonetheless valuable record of specimens from some pathology departments dating back to the 1970s. The data are of high quality and completeness and are sufficient to allow precise and efficient localization of the specimens. We describe the relatively uncomplicated procedures required to use these pathology databases in clinical research and to gain access to the archived specimens.
    Full-text · Article · Aug 2010 · Clinical Epidemiology
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    ABSTRACT: The classification problem consists of using some known objects, usually described by a large vector of features, to induce a model that classifies others into known classes. Feature selection is widely used as the first stage of the classification task to reduce the dimension of the problem, decrease noise and improve speed by the elimination of irrelevant or redundant features. The present paper deals with the optimization of nearest neighbour classifiers via intelligent and nature inspired algorithms for a very significant medical problem, the Pap smear cell classification problem. The algorithms used include tabu search, genetic algorithms, particle swarm optimization and ant colony optimization. The proposed complete algorithmic scheme is tested on two sets of data. The first consists of 917 images of Pap smear cells and the second set consists of 500 images, classified carefully by expert cyto-technicians and doctors. Each cell is described by 20 numerical features, and the cells fall into seven classes representing a variety of normal and abnormal cases. Nevertheless, from the medical diagnosis viewpoint, a minimum requirement corresponds to the general two-class problem of correct separation between normal and abnormal cells.
    No preview · Article · Nov 2009 · Expert Systems
  • G Dounias · B Bjerregaard · J Jantzen · A Tsakonas · N Ampazis · G Panagi · E Panourgias
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    ABSTRACT: In this study the performance of various intelligent methodologies is compared in the task of pap-smear diagnosis. The selected intelligent methodologies are briefly described and explained, and then, the acquired results are presented and discussed for their comprehensibility and usefulness to medical staff, either for fault diagnosis tasks, or for the construction of automated computer-assisted classification of smears. The intelligent methodologies used for the construction of pap-smear classifiers, are different clustering approaches, feature selection, neuro-fuzzy systems, inductive machine learning, genetic programming, and second order neural networks. Acquired results reveal the power of most intelligent techniques to obtain high quality solutions in this difficult problem of medical diagnosis. Some of the methods obtain almost perfect diagnostic accuracy in test data, but the outcome lacks comprehensibility. On the other hand, results scoring high in terms of comprehensibility are acquired from some methods, but with the drawback of achieving lower diagnostic accuracy. The experimental data used in this study were collected at a previous stage, for the purpose of combining intelligent diagnostic methodologies with other existing computer imaging technologies towards the construction of an automated smear cell classification device.
    No preview · Article · Feb 2006 · Oncology Reports
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    Mogens Vyberg · Beth Bjerregaard · Martin Bak · Inge Gram · Henrik Hvolris

    Full-text · Article · Apr 2005 · Ugeskrift for laeger
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    ABSTRACT: To demonstrate and compare the application of different genetic programming (GP) based intelligent methodologies for the construction of rule-based systems in two medical domains: the diagnosis of aphasia's subtypes and the classification of pap-smear examinations. Past data representing (a) successful diagnosis of aphasia's subtypes from collaborating medical experts through a free interview per patient, and (b) correctly classified smears (images of cells) by cyto-technologists, previously stained using the Papanicolaou method. Initially a hybrid approach is proposed, which combines standard genetic programming and heuristic hierarchical crisp rule-base construction. Then, genetic programming for the production of crisp rule based systems is attempted. Finally, another hybrid intelligent model is composed by a grammar driven genetic programming system for the generation of fuzzy rule-based systems. Results denote the effectiveness of the proposed systems, while they are also compared for their efficiency, accuracy and comprehensibility, to those of an inductive machine learning approach as well as to those of a standard genetic programming symbolic expression approach. The proposed GP-based intelligent methodologies are able to produce accurate and comprehensible results for medical experts performing competitive to other intelligent approaches. The aim of the authors was the production of accurate but also sensible decision rules that could potentially help medical doctors to extract conclusions, even at the expense of a higher classification score achievement.
    Full-text · Article · Dec 2004 · Artificial Intelligence in Medicine
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    ABSTRACT: We analyzed genetic changes in condylomas (four cases), vulvar intraepithelial neoplasia I-III (VIN I-III, eleven cases), and primary vulvar squamous cell carcinomas (VSCC, ten cases) by high-resolution comparative genomic hybridization (HR-CGH) and flowcytometry. All samples were also human papilloma virus (HPV)-genotyped. Gain of chromosome 1, the aberration most often seen in VIN III (67%), was not seen in HPV-positive or -negative VSCCs (0%). Both VIN III and VSCC frequently showed gain of 3q (56 and 70%, respectively). The VIN III samples often demonstrated gain of 20q (56%) and 20p (44%), and the VSCC samples gain of 8q (60%), loss of 3p (50%), and 8p (40%). None of the four most frequent changes in the VSCC samples occurred exclusively in the HPV-positive or -negative samples. As expected, we did not find any cytogenetic changes in condylomas and nearly any changes in VIN I-II.
    No preview · Article · Feb 2004 · Cytogenetic and Genome Research
  • G Panagi · B Bjerregaard · J Jantzen · N Ampazis · A Tsakonas · E Panourgias · G Dounias

    No preview · Conference Paper · Jan 2004
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    ABSTRACT: This paper demonstrates two methodologies for the construction of rule-based systems in medical decision making. The first approach consists of a method combining genetic programming and heuristic hierarchical rule-base construction. The second model is composed by a strongly-typed genetic programming system for the generation of fuzzy rule-based systems. Two different medical domains are used to evaluate the models. The first field is the diagnosis of subtypes of Aphasia. Two models for crisp rule-bases are presented. The first one discriminates between four major types and the second attempts the classification between all common types. A third model consisted of a GPgenerated fuzzy rule-based system is tested on the same domain. The second medical domain is the classification of Pap-Smear Test examinations where a crisp rulebased system is constructed. Results denote the effectiveness of the proposed systems. Comparisons on the system's comprehensibility and the transparency are included. These comparisons include for the Aphasia domain, previous work consisted of two neural network models.
    Full-text · Article · Mar 2002
  • Antonio Aru · Peter Norup · Beth Bjerregaard · Benny Andreasson · Thomas Horn
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    ABSTRACT: Osteoclast-like giant cells (OLGC) in leiomyomatous tumors of the uterus are rarely seen, and their significance is unknown. We present a case of a large leiomyomatous tumor in which OLGC were found in only few sections showing leiomyosarcoma whereas the majority of sections revealed a leiomyoma. Though radically operated, the patient died a few months later with recurrent tumor in the pelvis and metastases to the lungs.
    No preview · Article · May 2001 · Acta Obstetricia Et Gynecologica Scandinavica
  • Beth Bjerregaard · Jan Jantzen · D Landwehr · A G Foldberg

    No preview · Conference Paper · May 2001
  • Antonio Aru · Peter Norup · Beth Bjerregaard · Benny Andreasson · Thomas Horn
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    ABSTRACT: Osteoclast-like giant cells (OLGC) in leiomyomatous tumors of the uterus are rarely seen, and their significance is unknown. We present a case of a large leiomyomatous tumor in which OLGC were found in only few sections showing leiomyosarcoma whereas the majority of sections revealed a leiomyoma. Though radically operated, the patient died a few months later with recurrent tumor in the pelvis and metastases to the lungs.
    No preview · Article · Mar 2001 · Acta Obstetricia Et Gynecologica Scandinavica
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    ABSTRACT: To assess the validity of low-field MR in staging cervical cancer compared to clinical staging. A total of 95 women entered the study over a 3-year period. MR examinations with a 0.1 T resistive magnet using a body coil and clinical staging according to the FIGO recommendations (1988) were performed within 2 weeks from clinical diagnosis. T1- and T2-weighted sequences were obtained in transversal and sagittal acquisitions, and an additional T1 before and after contrast (randomisation to 0.1 or 0.3 mmol/kg b.w. gadodiamide). Treatment decisions on surgery or radiation therapy were made solely on the clinical staging. Sixty-one patients were found to be eligible for surgery. In 5 women, the pathological results revealed a more advanced stage of the disease than assessed by clinical staging. MR correctly staged 4 of the 5 but otherwise tended to overstate the disease. Contrast enhancement significantly reduced this trend (p<0.05) regardless of the contrast medium dose used. Divided into two groups, an operable (less than stage 2b) and an inoperable group (more than stage 2a), the clinical staging correctly classified 57 patients (accuracy 92%) compared to 52 patients with MR using contrast enhancement (accuracy 84%). The specificity was no higher than 31%, whereas the reproducibility of the MR assessment was fairly good with kappa values around 0.65 for both intra- and inter-observer variations. Conclusion: In the present set-up, clinical assessment was superior to low-field MR in staging cervical cancer. When using contrast enhancement, the staging accuracies of low-field MR were comparable to the ones reported for techniques with higher tesla values, whereas the specificity and reproducibility errors were lower. The method, therefore, needs to be optimised.
    No preview · Article · Dec 2000 · Acta Radiologica

  • No preview · Conference Paper · Mar 2000

  • No preview · Conference Paper · Mar 1999
  • C Riber · H Tønnesen · A Aru · B Bjerregaard
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    ABSTRACT: The objectives of this study were to determine observer variation in the assessment of the histopathologic diagnosis of acute appendicitis. Two consultant pathologists independently evaluated 415 appendectomy specimens (set I). After a consensus conference at which the observers unified the criteria of the diagnosis of acute appendicitis, another 396 appendectomy specimens (set II) were evaluated. To calculate the intra-observer variation, one observer evaluated set II once more. Finally, using the consensus diagnosis as the final diagnosis, the diagnostic accuracy of the surgeon, the primary pathology report, and the two observer evaluations was calculated. In set I no difference was found in the level of agreement on the diagnosis of acute appendicitis versus other diagnoses, and a kappa value of 0.85 was obtained. In set II a kappa value of 0.88 was obtained, which was not significantly different from the kappa value in set I. However, the consensus conference did increase the level of agreement on the diagnosis of acute appendicitis. The intra-observer variation was calculated, and a kappa value of 0.88 was obtained. The cases in which the observers disagreed on a positive diagnosis were cases of mild appendicitis. The question remains how many specimens would have shown these changes if all tissue had been developed for microscopy. The observers' diagnoses were the most reliable, and there was a significant decrease in the diagnostic accuracy compared with both the primary pathology report and the surgeon's opinion, the last one being the least accurate. These observations stress how important it is for the pathologist to discuss the diagnostic criteria of the diagnosis of acute appendicitis and for the surgeon to go back to the patient's record and look up the histopathologic diagnosis.
    No preview · Article · Feb 1999 · Scandinavian Journal of Gastroenterology
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    ABSTRACT: A possible relation between joint replacement and malignancy has previously been suggested in a few cases. In the majority of these cases, the authors found either malignant fibrous histiocytomas or osteosarcomas. We hereby report the first case of a liposarcoma in the vicinity of a joint prosthesis.
    Full-text · Article · Feb 1999 · International Orthopaedics
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    ABSTRACT: Næsten alle kvinder i Danmark deltager i vaginalcytologiske screeningsprogrammer dvs. regelmæssige undersø gelser af celler (smear) fra livmoderhalsen. Smearscreening er i dag hovedsagelig en manuel procedure. Formålet med vores projekt er at udvikle et computerstyret system til automatisk screening for livmoderhalskræft med samme eller bedre diagnostiske kvalitet end den nuværende manuelle screening og til en salgspris, så der spares ressourcer. Projektet er et offentligt/privat udviklingsprojekt stø ttet af Erhvervsfremme Styrelsen. Projektet er et lærestykke i samarbejde mellem forskellige instanser ved opstart af et stø rre projekt i sygehusregi inddragende Patologisk-anatomisk Institut, Amtsssygehuset i Herlev, Sygehusdirektoratet og Centralindkø b, Kø benhavns Amt, Patologisk Institut, Randers Centralsygehus og Danmarks Tekniske Universitet. Projektet startede 1. juli 1998 og resultatet af en pilotundersø gelse viser, at de allerede tilgængelige teknikker og viden hos både den offentlige og den private part er velegnede til at lø se opgaven.
    No preview · Article · Jan 1999
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    ABSTRACT: We present a case of Mazabraud's syndrome, a rare benign disease, with multiple intramuscular myxomas of the thoracic wall associated with fibrous dysplasia of bone. CT, MR imaging and ultrasonography (US) of the thorax showed 2 well circumscribed homogeneous intramuscular tumors. A US-guided needle biopsy with a large-core needle (2.0 mm) and a fine needle (0.8 mm) showed that the tumors were intramuscular myxomas with no sign of malignancy. 99mTc bone scintigraphy showed a markedly increased uptake in the right lower skull, and multiple smaller foci. CT of the skull revealed a right-sided unilateral bone thickening of the orbit and the ethmoidal cells, and right-sided exophthalmia. This case history suggests that patients with multiple intramuscular myxomas should be preoperatively examined for osseous lesions. A postoperative follow-up should also be performed to detect other soft-tissue myxomas not as yet clinically detectable, or rare osseous complications.
    No preview · Article · Jun 1997 · Acta Radiologica