1,720,978 research outputs found
A Registration Framework for Evaluation of T1, T2 and DWI Signal Intensities in Multiple Myeloma.
No full textQuantitative characterization and identification of lymph nodes and Nasopharingeal Carcinoma by coregistered magnetic resonance images
No full textIn this study we developed a technique to improve the identification of carcinoma and pathological lymph nodes in cases of Nasopharingeal Carcinoma (NPC), through a quantitative characterization of the tissues based on MR images: 3D VIBE (Volumetric Interpolated Breath-hold Examination) T1-CE (Contrast Enhanced), T1, T2 and Diffusion Weighted Imaging (DWI) for b-values 0,300,500,700,1000. The procedure included two phases: 1) coregistration of volumes and 2) tissue characterization.
Concerning the first phase, the DICOM images were reassembled spatially and resampled with isotropic 0.5mm resolution. Coregistration was performed by two multiresolution rigid transformations, merging head and neck volumes, plus a final multiresolution non rigid transformation. The anatomical 3D CE-VIBE volume was taken as reference.
The procedure for tissue characterization is semi automated and it required a radiologist to identify an example of tissue from the primary tumor and a metastatic lymph node. We generated a 8-dimensional membership function to perform a fuzzy-like identification of these tissues. The result of this procedure was the generation of two maps, which showed complementary characterization of lymph nodes and carcinoma. A few example will be shown to evidence the potentiality of this method in identification and characterization of NPC lesions
ITAC volume assessment through a Gaussian hidden Markov random field model-based algorithm
No full textBlunt trauma of the spleen: the delayed rupture in computed tomography
No full textWe retrospectively reviewed CT scans of 18 patients (12 males and 6 females; mean age: 43.6 years) with the diagnosis of blunt splenic trauma. All patients underwent CT at different times after the trauma. The cases were divided into 2 groups: according to the time at which the CT was perfomed, the 1st group consisted of 11 patients scanned within 48 h after the trauma; the 2nd group consisted of 7 patients studied with CT at variable times after the traumatic event (mean time: 6.5 days; range 3-13 days). All lesions in the 1st group (11 patients) had indistinct margins, while lesions of patients in the 2nd group (7 patients) always showed clean-cut and regular edges. Early lesions were always hyperdense, late ones hypodense. CT diagnosis always matched the surgeon's diagnosis . We can confirm the diagnostic value of CT of splenic lesions in blunt abdominal traumas
Sviluppo di un algoritmo di segmentazione EM per la determinazione della volumetria delle neoplasie delle fosse nasali e dei seni paranasali da indagini di risonanza magnetica
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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
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