1,720,957 research outputs found
Interventional Radiology in the Biliary Tree, Liver, and Pancreas
No full textInterventional radiology offers the opportunity to perform several diagnostic and therapeutic procedures, with the advantage of a mini-invasive percutaneous approach. Many vascular procedures can be performed, once a transarterial or transvenous access is obtained. Biliary interventions are usually performed to treat bile duct strictures or to reconstitute biliary drainage after major surgical interventions complicated by bile duct damage. Hepatic transvenous procedures offer the opportunity to efficiently treat portal hypertension, one of the major cirrhosis-related problems.
Oncologic patients can be accurately diagnosed through ultrasound-guided or computed tomography-guided acquisition of tissue samples (biopsy) or aspirate. Moreover, they can receive a broad spectrum of percutaneous treatments, developed from the application of different physical principles
Pancreatic Cancer
No full textBook Overview: Provides the reader with a fully integrated multimodality approach (radiology and molecular imaging); Focused on diagnostic pathways for the staging and re-staging of oncologic disease; Presents therapeutic strategies in oncology, with image-guided interventions as well a
Quantitative Edge Analysis Can Differentiate Pancreatic Carcinoma from Normal Pancreatic Parenchyma
No full text: This study aimed to introduce specific image feature analysis, focusing on pancreatic margins, and to provide a quantitative measure of edge irregularity, evidencing correlations with the presence/absence of pancreatic adenocarcinoma. We selected 50 patients (36 men, 14 women; mean age 63.7 years) who underwent Multi-detector computed tomography (MDCT) for the staging of pancreatic adenocarcinoma of the tail of the pancreas. Computer-assisted quantitative edge analysis was performed on the border fragments in MDCT images of neoplastic and healthy glandular parenchyma, from which we obtained the root mean square deviation SD of the actual border from the average boundary line. The SD values relative to healthy and neoplastic borders were compared using a paired t-test. A significant SD difference was observed between healthy and neoplastic borders. A threshold SD value was also found, enabling the differentiation of adenocarcinoma with 96% specificity and sensitivity. We introduced a quantitative measure of boundary irregularity, which correlates with the presence/absence of pancreatic adenocarcinoma. Quantitative edge analysis can be promptly performed on select border fragments in MDCT images, providing a useful supporting tool for diagnostics and a possible starting point for machine learning recognition based on lower-dimensional feature space
The Many Faces of the Angry Peritoneum
No full textThe peritoneum is a thin membrane that lines the abdominal cavity and covers the abdominal organs. It serves as a conduit for the spread of various pathological processes, including gas and fluid collections, inflammation, infections, and neoplastic conditions. Peritoneal carcinomatosis is the most common and well-known pathology involving the peritoneum, typically resulting from the dissemination of gastrointestinal and pelvic malignancies. However, numerous benign and malignant peritoneal diseases can mimic the imaging appearance of peritoneal carcinomatosis. The aim of this review is to revisit the anatomy of peritoneal compartments and elucidate the patterns of peritoneal disease spread. Emphasis is placed on identifying the distinctive imaging features of both neoplastic and non-neoplastic peritoneal diseases that differ from peritoneal carcinomatosis
A Case of Wernicke’s Encephalopathy After Sleeve Gastrectomy
No full textBackground: Wernicke's encephalopathy, resulting from thiamine deficiency, is a rare but serious neurological complication of bariatric procedures. A clinical and radiologic diagnosis is often difficult, and thiamine blood tests are not broadly available. Only a few cases of Wernicke's encephalopathy after sleeve gastrectomy have been reported in the literature, nonetheless, subjects can be underdiagnosed, and their cases can be underreported. Case presentation: We present the case of a 20-year-old female patient who developed Wernicke's encephalopathy after sleeve gastrectomy for grade II obesity with metabolic complications. She was presented to the Emergency Department showing confusion, gait ataxia and horizontal nystagmus two months after surgery. Persistent vomiting and lack of compliance with vitamin intake were reported. Cerebral MRI showed acute bilateral lesions in the periaqueductal and periventricular regions. Parenteral thiamine supplementation was administered, obtaining a progressive resolution of altered mental status, motor ataxia, and nystagmus. She was discharged on oral thiamine supplementation and underwent a multidisciplinary rehabilitation program, since anterograde, retrograde, and working memory impairment persisted. After a 2-year follow-up, she was compliant with a balanced fractionated diet and vitamin supplementation. A new cerebral MRI showed regression of the neuroradiological findings, but minimal memory impairment remained. Conclusion: Wernicke's encephalopathy is a concrete possibility after sleeve gastrectomy and should always be suspected in patients with recurrent vomiting, poor nutritional intake, and non-compliance to vitamin supplementation. Immediate and aggressive thiamine supplementation is mandatory to prevent patients from irreversible neurological impairment, even though full recovery is not always achieved
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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