1,720,961 research outputs found
18F-Choline PET/CT-Positive Lytic Bone Lesions in Prostate Cancer and Accidental Myeloma Detection
No full textABSTRACT: F-choline PET/CT was performed for suspected prostate cancer relapse in a 67-year-old man with hip pain and a rapid rise in prostate-specific antigen values (1.1 ng/mL). PET imaging showed an area of increased F-choline bone uptake in the right ischium. Coregistered CT images showed a lytic bone lesion. The infrequent CT appearance of a possible prostate carcinoma metastasis led to additional laboratory testing that showed a monoclonal γ-peak and to subsequent biopsy, which revealed a solitary plasmocytoma
The prognostic value of F-18 fluorodeoxyglucose bone marrow uptake in patients with recent diagnosis of multiple myeloma : a comparative study with Tc-99m sestamibi
No full textPurpose: We assessed the prognostic value of F-18 fluorodeoxyglucose (FDG) uptake in the bone marrow of patients with multiple myeloma (MM) in comparison with Tc-99m methoxy-isobutyl-isonitrile (MIBI). Methods: The extent and intensity of FDG and MIBI uptake in the bone marrow of 18 patients with a recent diagnosis of MM were assessed by visual score and by calculating the mean SUV (mSUV) for FDG and the femora/thigh ratio (TG/BKG, [Target/Background ratio]) for MIBI images. These parameters were correlated with clinical indexes of disease using hemoglobin and beta-2-microglobulin levels and plasma cell infiltrate (PCI) percentage. The mean values of the visual score, mSUV, and TG/BKG levels were compared in patients deceased after a relatively short follow-up (n = 9; group A) and in patients with a longer survival or were alive at the end of the study (n = 9; group B). Results: Significant correlations of mSUV and TG/BKG values with PCI percentages and beta-2-microglobulin were found (P < 0.05). The extent of FDG and MIBI bone marrow uptake was greater in patients of group A (P < 0.01). Higher values of mSUV (P < 0.01) and TG/BKG (P < 0.05) were also observed in patients of group A. These results were consistent with the differences (not statistically significant) in hemoglobin, albumin, beta-2-microglobulin levels, and PCI percentages observed in the 2 groups. Conclusion: Our study demonstrates that an increase of FDG bone marrow uptake may predict a more aggressive disease, as much as MIBI uptake. Therefore, an additional analysis of FDG bone marrow images should be performed in patients undergoing PET studies during the initial staging of MM
Staging non-small lung cancer with positron emission tomography: diagnostic value, impact on patient management, and cost-effectiveness
No full textThe aim of this study was to compare two preoperative staging procedures of non-small cell lung cancer (NSCLC): one using positron emission tomography (PET) and one using conventional imaging studies. Accuracy, effects on patient management, and costs were calculated. Four hundred thirteen consecutive patients with NSCLC were prospectively examined with PET and conventional imaging studies. A simulation calculated the costs of the two strategies. The accuracy of PET for metastases was 97.5% versus 84% of conventional imaging (P < 0.001). The accuracy of PET for mediastinal staging was 97%, whereas that of computed tomography was 68% (P < 0.001). The expected number of unnecessary surgeries was 24 for the conventional strategy and 8 for the PET strategy (P = 0.007). The PET strategy was less expensive. This study shows that PET is an economical tool in NSCLC staging (even in the European economic environment), with high accuracy and important management aspects
Role of Tc-99m sestamibi scintigraphy in the diagnosis and surgical decision-making process in primary hyperparathyroid disease
No full textUltrasound (US) and scintigraphy are used most frequently of all the available imaging techniques for the preoperative evaluation of patients with possible primary hyperparathyroid disease. The aim of this study was to assess the value of dual-phase Tc-99m MIBI scintigraphy compared with US in the detection of adenomatous or hyperplastic glands and in the surgical decision-making process for patients with a biochemical diagnosis of primary hyperparathyroid disease
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
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