1,720,961 research outputs found
Magnetic resonance imaging of breast cancer: Does the time interval between biopsy and MRI influence MRI-pathology discordance in lesion sizing?
No full textBackground Breast magnetic resonance imaging (MRI) is more accurate than ultrasound and mammography in estimating local extension of both invasive breast cancer and ductal carcinoma in situ (DCIS) and it is part of a breast cancer patient's preoperative management. Purpose To verify if time interval between breast biopsy and preoperative MRI, lesion margins, and biopsy technique can influence tumor sizing on MRI. Material and Methods By a database search, we retrospectively identified all women with a newly diagnosed, biopsy-proven, primary breast cancer who underwent MRI before surgery. The time interval between biopsy and MRI, the type of biopsy procedure, and various pathological features of tumors were collected. We defined the concordance between MRI and pathology measurements as a difference of 30 days (P < 0.05). By means of multivariate analysis, we found that DCIS subtype and the presence of poorly defined margins on MRI are the only two factors independently and strongly associated with MRI-pathology discordance in lesion sizing. Conclusion Size, histology, and margins of tumors may affect the accuracy of MRI measurements. The type of biopsy procedure and the time interval between biopsy and preoperative MRI are not independently associated to MRI-pathology discordance
Incidental physiological sliding hiatal hernia: a single center comparison study between CT with water enema and CT colonography
No full textPURPOSE:
Hiatal hernia is a well-known factor impacting on most mechanisms underlying gastroesophageal reflux, related with the risk of developing complications such as erosive esophagitis, Barrett's esophagus and ultimately, esophageal adenocarcinoma. It is our firm opinion that an erroneous reporting of hiatal hernia in CT exams performed with colonic distention may trigger a consecutive diagnostic process that is not only unnecessary, inducing a unmotivated anxiety in the patient, but also expensive and time-consuming for both the patient and the healthcare system. The purposes of our study were to determine whether colonic distention at CT with water enema and CT colonography can induce small sliding hiatal hernias and to detect whether hiatal hernias size modifications could be considered significant for both water and gas distention techniques.
METHODS:
We retrospectively evaluated 400 consecutive patients, 200 undergoing CT-WE and 200 undergoing CTC, including 59 subjects who also underwent a routine abdominal CT evaluation on a different time, used as internal control, while a separate group of 200 consecutive patients who underwent abdominal CT evaluation was used as external control. Two abdominal radiologists assessed the CT exams for the presence of a sliding hiatal hernia, grading the size as small, moderate, or large; the internal control groups were directly compared with the corresponding CT-WE or CTC study looking for a change in hernia size. We used the Student's t test applying a size-specific correction factor, in order to account for the effect of colonic distention: these "corrected" values were then individually compared with the external control group.
RESULTS:
A sliding hiatal hernia was present in 51 % (102/200) of the CT-WE patients and in 48.5 % (97/200) of the CTC patients. Internal control CT of the 31 patients with a hernia at CT-WE showed resolution of the hernia in 58.1 % (18/31) of patients, including 76.5 % (13/17) and 45.5 % (5/11) of small and moderate hernias. Comparison CT of the 28 patients with a hiatal hernia at CTC showed the absence of the hernia in 57.1 % (16/28) patients, including 68.8 % (11/16) and 50 % (5/10) of small and moderate hernias. The prevalence of sliding hiatal hernias in the external control group was 22 % (44/200), significantly lower than the CT-WE and CTC cohorts' prevalence of 51 % (p < 0.0001) and 48.5 % (p < 0.0001). After applying the correction factors for the CT-WE and the CTC groups, the estimated residual prevalences (16 and 18.5 %, respectively) were much closer to that of the external control patients (p = 0.160 for CT-WE and p = 0.455 for CTC).
CONCLUSIONS:
We believe that incidental findings at CT-WE and CTC should be considered according to the clinical background, and that small sliding hiatal hernias should not be reported in patients with symptoms not related to reflux disease undergoing CT-WE or CTC: When encountering these findings, accurate anamnesis and review of medical history looking for GERD-related symptoms are essential, in order to address these patients to a correct diagnostic iter, taking advantage from more appropriate techniques such as endoscopy or functional techniques
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Seronegative spondyloarthropathies: what radiologists should know
No full textInflammatory involvement of the spine and sacroiliac joints is the most peculiar feature of seronegative spondyloarthropathies (SpA), which include ankylosing spondylitis, psoriatic arthritis, reactive arthritis (Reiter's syndrome), enteropathic spondylitis (related to inflammatory bowel diseases) and undifferentiated spondyloarthropathies. SAPHO syndrome may also be considered a SpA, but there is no clear agreement in this respect. Imaging, along with clinical and laboratory evaluation, is an important tool to reach a correct diagnosis and to provide a precise grading of disease progression, influencing both clinical management and therapy. Conventional radiography, which is often the first-step imaging modality in SpA, does not allow an early diagnosis. Computed tomography (CT) demonstrates with a very high spatial resolution the tiny structural alterations of cortical and spongy bone before they become evident on plain film radiographs. Magnetic resonance imaging (MRI) is the only modality that provides demonstration of bone marrow oedema, which reflects vasodilatation and inflammatory hyperaemia. The primary aim of this review article was to examine the involvement of the spine and sacroiliac joints in SpA using a multimodal radiological approach (radiography, CT, MRI), providing a practical guide for the differential diagnosis of these conditions
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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