1,720,980 research outputs found
Advanced Imaging of Pancreatic Neoplasms
No full textImaging has a pivotal role in pancreatic neoplasms, ranging from diagnosis to treatment monitor. It is crucial, especially for pancreatic ductal adenocarcinoma (PDAC), to obtain an early diagnosis, since the therapeutic approach is mainly surgical and may be curative only in early-stage disease. For this reason, every advance in imaging should be evaluated and tested to produce a step forward in lesion identification
Malignant obstructive jaundice: Imaging and percutaneous intervention
No full textiliary obstruction is a common clinical problem. Malignant obstructive jaundice is frequently caused by cholangiocarcinoma and pancreatic head adenocarcinoma, which are often inoperable at presentation and carry a dismal prognosis; less common causes include metastatic lymph nodes at the hepatic hilum and gallbladder cancer. The management of patients with a suspected malignant biliary obstruction ultimately depends on local expertise, availability, cost, and the multidisciplinary cooperation. An adequate assessment of malignant obstructive jaundice requires the use of various noninvasive imaging modalities, as ultrasound, computed tomography and magnetic resonance imaging to identify the level and the cause of the obstruction and to plan the treatment. Percutaneous intervention is an effective method of palliation in such patients, thereby improving their quality of life. It may also be an adjunct to surgical management by improving hepatic function before surgical resection or neoadjuvant therapy. This chapter reviews standards of care in terms of non-invasive diagnosis and percutaneous treatment of malignant biliary obstruction
fMRI in Resting State as a Radiological Tool in Pharmaceutic Research: An Experimental Clinical Trial with Alprazolam
No full textPURPOSE: The aim of the study was to highlight the presence of modifications in the Default Mode Network (DMN) detected by means of fMRI in Resting State after
the administration of a neurotropic drug, the Alprazolam, and therefore to suggest fMRI as an alternative and non invasive tool for future pharmacological
experimentations in vivo.
METHOD AND MATERIALS: 11 healthy subjects (5 males; mean age: 32 years) were enrolled in a double-blind randomized study. They received Alprazolam or
placebo and underwent two fMRI scans each. Data were acquired at 1.5 T (Magnetom Symphony, Siemens, Enlargen, Germany). Functional connectivity and
activation maps were obtained by means of independent component analysis using FSL (FMRIB software Library 4.1, Oxford, UK). A F-test (p<0.05) was applied in
order to detect statistical differences between groups and Dual-Regression (p<0.05) permitted to obtain spatial maps defining the between-subject
group-consistency.
RESULTS: The reproducibility of fMRI in Resting State was demonstrated with a consistent detection of DMN in all subjects and all conditions, furthermore a
statistically non-significant difference between baselines was found (p<0,11242). The Dual-Regression analysis showed a diffuse significant higher functional
connectivity in the brain after the administration of Alprazolam, mainly in the precuneus/posterior cingulate cortex within the DMN, and also between the DMN and
other cerebral areas, in particular the basal ganglia. No significant differences in DMN were detected after placebo administration.
CONCLUSION: fMRI in Resting State reproducibility was demonstrated and connectivity modifications in DMN and other cerebral areas occur after Alprazolam
administration.
CLINICAL RELEVANCE/APPLICATION: fMRI should be considered an applicable model in humans during future clinical trials
Analisi radiomica delle modificazioni dopo radioterapia neoadiuvante in pazienti con adenocarcinoma del pancreas
No full textNo abstract availabl
Path Tracing vs. Volume Rendering Technique in Post-Surgical Assessment of Bone Flap in Oncologic Head and Neck Reconstructive Surgery: A Preliminary Study
Full text linkThis study aims to compare a relatively novel three-dimensional rendering called Path Tracing (PT) to the Volume Rendering technique (VR) in the post-surgical assessment of head and neck oncologic surgery followed by bone flap reconstruction. This retrospective study included 39 oncologic patients who underwent head and neck surgery with free bone flap reconstructions. All exams were acquired using a 64 Multi-Detector CT (MDCT). PT and VR images were created on a dedicated workstation. Five readers, with different expertise in bone flap reconstructive surgery, independently reviewed the images (two radiologists, one head and neck surgeon and two otorhinolaryngologists, respectively). Every observer evaluated the images according to a 5-point Likert scale. The parameters assessed were image quality, anatomical accuracy, bone flap evaluation, and metal artefact. Mean and median values for all the parameters across the observer were calculated. The scores of both reconstruction methods were compared using a Wilcoxon matched-pairs signed rank test. Inter-reader agreement was calculated using Spearman’s rank correlation coefficient. PT was considered significantly superior to VR 3D reconstructions by all readers (p < 0.05). Inter-reader agreement was moderate to strong across four out of five readers. The agreement was stronger with PT images compared to VR images. In conclusion, PT reconstructions are significantly better than VR ones. Although they did not modify patient outcomes, they may improve the post-surgical evaluation of bone-free flap reconstructions following major head and neck surgery
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
VALUTAZIONE CON IVIM-DWI DELLE LESIONI SOLIDE DEL PANCREAS: RIPRODUCIBILITÀ ED UTILITÀ PER LA DIFFERENZIAZIONE
No full textnon disponibile; comunicazione oral
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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