Search results for "Sound"
showing 10 items of 1845 documents
Quality control for exposure assessment in epidemiological studies
2010
In the framework of an epidemiological study, dosemeters were used for the assessment of radio frequency electromagnetic field exposure. To check the correct dosemeter's performance in terms of consistency of recorded field values over the entire study period, a quality control strategy was developed. In this paper, the concept of quality control and its results is described. From the 20 dosemeters used, 19 were very stable and reproducible, with deviations of a maximum of +/- 1 dB compared with their initial state. One device was found to be faulty and its measurement data had to be excluded from the analysis. As a result of continuous quality control procedures, the confidence in the meas…
Theoretical and experimental study of the role of cell-cell dipole interaction in dielectrophoretic devices: application to polynomial electrodes
2013
BACKGROUND: We aimed to investigate the effect of cell-cell dipole interactions in the equilibrium distributions in dielectrophoretic devices. METHODS: We used a three dimensional coupled Monte Carlo-Poisson method to theoretically study the final distribution of a system of uncharged polarizable particles suspended in a static liquid medium under the action of an oscillating non-uniform electric field generated by polynomial electrodes. The simulated distributions have been compared with experimental ones observed in the case of MDA-MB-231 cells in the same operating conditions. RESULTS: The real and simulated distributions are consistent. In both cases the cells distribution near the elec…
Color-coded duplex endoscopic ultrasound of the adrenals.
2008
Imaging of the adrenals by endoscopic ultrasound (EUS) is a valuable technique for detection and localization of adrenal lesions, but endosonomorphological tumor distinction remains difficult. In this single-center study, the amount of blood flow in common adrenal lesions, such as adrenal adenomas, adrenal hyperplasia, and pheochromocytomas, was visualized by color-coded duplex EUS (CD-EUS) and was retrospectively analysed. Therefore, we reviewed our EUS database to evaluate and correlate the perfusion patterns of common adrenal lesions with histologically confirmed diagnosis, possible malignancy, and endosonomorphological features such as echogeneity, echostructure, and tumor size. CD-EUS …
Choledochocele imaged with magnetic resonance cholangiography.
2000
Choledochal cysts are rare developmental malformations of the biliary tree. Percutaneous and endoscopic ultrasound, as well as endoscopic retrograde cholangiopancreatography, are recommended diagnostic tools. Magnetic resonance cholangiography may also contribute to the workup and treatment plan of patients with choledochal cysts. We report a 25-yr-old white woman with episodic nausea and moderate epigastric dyscomfort. Magnetic resonance cholangiography showed a rather spherical, cyst-like, fluid-filled structure in continuity with the prepapillary segment of the common bile duct, thus making a choledochocele (type III choledochal cyst) likely. The patient was treated by endoscopic sphinct…
German Survey on EUS-Guided Diagnosis and Management of Gastrointestinal Stromal Tumors (GISTs) - Evidence or "Gut-Feeling"?
2015
To examine practice patterns of endosonographers in diagnosing and managing gastrointestinal stromal tumors (GISTs) in Germany.A modified published survey (Ha et al., Gastrointest Endosc 2009) was sent to endosonographic ultrasound (EUS) customers in Germany. The survey was also publicized on the homepage of an EUS interest group. To avoid duplicate opinions, participants were asked to return one survey per institution.142 centers of roughly 850 German EUS centers responded. 25 % were from University hospitals and 74 % from community hospitals. 61 % performed 2 EUS scans for suspected subepithelial lesions/week. Although 97 % of respondents believed that tissue acquisition with CD117 immuno…
Curative endoscopic therapy in patients with early esophageal squamous-cell carcinoma or high-grade intraepithelial neoplasia.
2007
Background and study aims Endoscopic resection of esophageal squamous-cell neoplasia with curative intent is considered to be a safe and effective alternative treatment to radical surgery in cases where the neoplasia is intraepithelial or limited to the mucosal layer. These patients are at risk for recurrent malignancy in the preserved esophagus, however. We conducted a prospective study to evaluate the efficacy and safety of endoscopic resection and to analyze variables associated with recurrence in patients with mucosal or intraepithelial squamous-cell neoplasia. Patients and methods Between December 1997 and September 2005, 65 patients (mean age +/- standard deviation [SD] 62.9 +/- 9.5 y…
Biliopancreatic Endoscopy in Altered Anatomy
2021
Background and Objectives: Anatomical post-surgical alterations of the upper gastrointestinal (GI) tract have always been challenging for performing diagnostic and therapeutic endoscopy, especially when biliopancreatic diseases are involved. Esophagectomy, gastrectomy with various reconstructions and pancreaticoduodenectomy are among the most common surgeries causing upper GI tract alterations. Technological improvements and new methods have increased the endoscopic success rate in these patients, and the literature has been rapidly increasing over the past few years. The aim of this systematic review is to identify evidence on the available biliopancreatic endoscopic techniques performed i…
Direct image-guided retroperitoneal approach and treatment of the pancreas by using natural orifice transluminal endoscopic surgery after EUS sugar-a…
2021
Endoscopic ultrasound and early diagnosis of pancreatic cancer
2007
Incidence of pancreatic cancer has increased, but prognosis remains poor. Curative treatment is dependent on early diagnosis. Endoscopic ultrasound (EUS) has been described as highly sensitive and accurate in staging, superior to other imaging modalities in early publications. With rapid advances in technology, other imaging techniques have reached better results. EUS still has the highest accuracy in assessing tumor size and lymph node involvement. For assessment of tumor respectability, a combination of a computed tomography (CT) scan and EUS seems to be the procedure with the highest accuracy. Promising new techniques might improve the diagnostic yield of EUS. But there are several reaso…
Endoscopic ultrasonography findings in autoimmune pancreatitis
2011
Endoscopic ultrasonography is an established diagnostic tool for pancreatic masses and chronic pancreatitis. In recent years there has been a growing interest in the worldwide medical community in autoimmune pancreatitis (AIP), a form of chronic pancreatitis caused by an autoimmune process. This paper reviews the current available literature about the endoscopic ultrasonographic findings of AIP and the role of this imaging technique in the management of this protean disease.