Search results for "ULTRASOUND"
showing 10 items of 1259 documents
Entwicklung der Hornhautdicke während der UV-Vernetzungstherapie unter Anwendung verschiedener Kompositionen von Riboflavin-Augentropfen
2011
Background During the UVA-cross-linking treatment in keratoconus patients, the UVA rays are partially absorbed in the stroma of the riboflavin-loaded cornea. This effect protects the corneal endothelium from UVA irradiation damage. The intensity of UVA light reaching the endothelium is inversely correlated with corneal thickness. The common composition of riboflavin eye drops may lead to a marked reduction in corneal thickness increasing the risk of endothelial damage. Patients and methods In a retrospective analysis of 23 UVA-cross-linking procedures on 23 patients we collected data about the pre-, intra- and postoperative corneal thickness (measured with ultrasound). Among these patients …
Sonographische Verlaufskontrolle von experimentellen Muskelverletzungen
1995
Experimental muscle lesions were produced in 28 rabbits by stab incision, thus creating a lesion of known extent and site. The changes in the course of healing were followed up and documented at short intervals for a period of two months via sonography. The changes take place in regular course and can be explained by fine tissue changes, taking into consideration the fundamentals of theoretical ultrasound physics. Sonography renders both valuable assistance in diagnosing muscular lesions and in following up the healing process--the latter, however, with some reservations due to the clinical terminology defining the extent of muscular lesions.
New trends in photobiology
1993
Abstract At the beginning of our century few scientists paid attention to the phenomenon of inactivation of photosynthesis by high light intensities which was later called photoinhibition. In the period 1925–1950, the idea was established that photoinhibition is a reversible inactivation, determined by light intensity and exposure time, followed by irreversible damage of the photosynthetic apparatus. However, the absence of a uniform terminology demonstrates that photoinhibition was not completely perceived and understood. In 1956, B. Kok gave the first definition of photoinhibition as a photochemical inactivation of pigment complexes.
Hyperspectral venous image quality assessment for optimum illumination range selection based on skin tone characteristics
2014
Background Subcutaneous veins localization is usually performed manually by medical staff to find suitable vein to insert catheter for medication delivery or blood sample function. The rule of thumb is to find large and straight enough vein for the medication to flow inside of the selected blood vessel without any obstruction. The problem of peripheral difficult venous access arises when patient’s veins are not visible due to any reason like dark skin tone, presence of hair, high body fat or dehydrated condition, etc. Methods To enhance the visibility of veins, near infrared imaging systems is used to assist medical staff in veins localization process. Optimum illumination is crucial to obt…
Effects of high power ultrasound treatments on the phenolic, chromatic and aroma composition of young and aged red wine
2019
Abstract In this study, the effects of both ultrasonic bath and probe treatments on the phenolic, chromatic and aroma composition of young red wine Cabernet Sauvignon were studied and modeled by artificial neural networks (ANNs). Moreover, the effect of high power ultrasound (HPU) along with antioxidants addition (sulfur dioxide and glutathione) was investigated during 6 months of aging in bottles. Lower amplitude and temperature, shorter treatment duration and particularly lower frequency showed a more favorable and milder effect on the chemical composition of wine. In the case of the ultrasonic probe treatment, similar effect was achieved primarily by a larger probe diameter as well as lo…
Diagnóstico de Metástasis Ováricas de un linfoma B diseminado mediante ecografía 3D
2018
RESUMEN La participación del aparato genitourinario en el contexto de la enfermedad hematológica maligna es bien conocida. No obstante, la afectación ovárica por linfomas es inusual, ya sea de novo o como manifestación tardía de linfoma diseminado. El objetivo de esta comunicación es exponer la aportación diagnóstica de la ecografía tridimensional (3D) en la detección de metástasis ováricas, cuando todavía algunas de las pruebas de imagen estándar como la tomografía computarizada (TAC) son normales. En este caso presentamos una paciente con linfoma B difuso de células grandes mediastínico de crecimiento rápido y diseminación precoz a aparato gastrointestinal y genitourinario. ABSTRACT Genit…
Numerical and experimental study of liquid metal stirring by rotating permanent magnets
2018
In this work, we study liquid gallium stirring by rotating permanent magnets. We demonstrate possibility of easily creating different flow patterns by rotating permanent magnets, which can be industrially important for controlling heat and mass transfer processes in the system. Unlike the typical approach of simulating magnet rotation as a transient problem and time-averaging the Lorentz forces, we solve the magnet rotation as a harmonic (frequency domain) problem, which leads to forces equal to time-averaged ones and decreases the simulation time considerably. Numerical results are validated using qualitative flow structure results from the neutron radiography visualization of tracer parti…
Transjugular intrahepatic portosystemic shunt (TIPS) complications: what diagnostic radiologists should know
2022
Transjugular intrahepatic portosystemic shunt (TIPS) is an effective therapy for portal hypertension complications and can successfully treat variceal bleeding and refractory ascites. Although TIPS is relatively safe, procedural- or shunt-related morbidity can reach 20%, and procedural complications have a fatality rate of 2%. Delayed recognition and treatment of TIPS complications can lead to life-threatening clinical scenarios. Complications can vary from stent migration or malpositioning to nontarget organ injury, TIPS dysfunction, encephalopathy, or liver failure. This review aims to outline the role of diagnostic radiology in assessing post-TIPS complications.[GRAPHICS].
Usefulness of alpha-fetoprotein in the diagnosis of hepatocellular carcinoma
2003
With the widespread use of ultrasonography (US) and computerized tomography (CT), the usefulness of α-fetoprotein assay in the diagnosis of hepatocellular carcinoma (HCC) has decreased. The aim of our study was to evaluate the best cut-off value for serum α-fetoprotein to discriminate between liver cirrhosis (LC) and HCC and the factors influencing levels in a Sicilian population. Three hundred and seventy-two patients with LC and 197 with HCC-associated LC were studied. The etiology was: HCV in 288 cases (77.4%) of LC and 147 cases (75%) of HCC; HBV in 31 cases (8.3%) of LC and 15 cases (7.6%) of HCC; HCV/HBV in 21 cases (5.6%) of LC and 6 cases (3.0%) of HCC; non-viral in 32 cases (8.6%) …
Contrast ultrasound LI-RADS LR-5 identifies hepatocellular carcinoma in cirrhosis in a multicenter restropective study of 1,006 nodules
2018
Background & Aims The use of contrast enhanced ultrasound (CEUS) for the diagnosis of hepatocellular carcinoma (HCC) in cirrhosis was questioned because of the risk of a false positive diagnosis in cases of cholangiocarcinoma. The American College of Radiology has recently released a scheme (CEUS Liver Imaging Reporting and Data System [LI-RADS®]) to classify lesions at risk of HCC investigated by CEUS. The aim of the present study was to validate this LI-RADS scheme for the diagnosis of HCC. Methods A total of 1,006 nodules from 848 patients with chronic liver disease at risk of HCC were collected in five Italian centers and retrospectively analyzed. Nodules were classified as LR-5, (HCC) …