Search results for "microbubbles"
showing 10 items of 25 documents
Conic optical fiber probe for generation and characterization of microbubbles in liquids
2021
Abstract A novel optical fiber probe has been developed to provide mechanical stability to microbubbles generated in fluids, the tip of the fiber is etched with hydrofluoric acid to pierce a truncated horn that fastens the microbubbles to the fiber tip and prevents misalignment or detachment caused by convection currents, vibrations or shocks in the liquid. Microbubbles are photo-thermally generated on the etched fiber and used as Fabry-Perot cavity sensor. Two methods were used to interrogate the probe: the first one, in the wavelength domain, is suitable for calibration in static or quasi static situations; the second one, in the time domain, can be used in dynamic environments. Experimen…
Targeting distinct myeloid cell populations in vivo using polymers, liposomes and microbubbles
2016
Identifying intended or accidental cellular targets for drug delivery systems is highly relevant for evaluating therapeutic and toxic effects. However, limited knowledge exists on the distribution of nano- and micrometer-sized carrier systems at the cellular level in different organs. We hypothesized that clinically relevant carrier materials, differing in composition and size, are able to target distinct myeloid cell subsets that control inflammatory processes, such as macrophages, neutrophils, monocytes and dendritic cells. Therefore, we analyzed the biodistribution and in vivo cellular uptake of intravenously injected poly(N-(2-hydroxypropyl) methacrylamide) polymers, PEGylated liposomes…
Parametrical Optomechanical Oscillations in PhoXonic Whispering Gallery Mode Resonators
2019
AbstractWe report on the experimental and theoretical analysis of parametrical optomechanical oscillations in hollow spherical phoxonic whispering gallery mode resonators due to radiation pressure. The optically excited acoustic eigenmodes of the phoxonic cavity oscillate regeneratively leading to parametric oscillation instabilities.
The added diagnostic value of 64-row multidetector CT combined with contrast-enhanced US in the evaluation of hepatocellular nodule vascularity: impl…
2009
The aim of this study was to assess the added diagnostic value of contrast-enhanced US (CEUS) combined with 64-row multidetector CT (CT) in the assessment of hepatocellular nodule vascularity in patients with liver cirrhosis. One hundred and six cirrhotic patients (68 male, 38 female; mean age +/- SD, 70 +/- 7 years) with 121 biopsy-proven hepatocellular nodules (72 hepatocellular carcinomas, 10 dysplastic and 15 regenerative nodules, 12 hemangiomas, and 12 other benignancies) detected during US surveillance were prospectively recruited. Each nodule was scanned by CEUS during the arterial (10-40 s), portal venous (45-90 s), and delayed sinusoidal phase (from 100 s after microbubble injectio…
Analysis of different contrast enhancement patterns after microbubble-based contrast agent injection in liver hemangiomas with atypical appearance on…
2006
BACKGROUND: We describe different possible enhancement patterns in liver hemangiomas with atypical appearance on baseline ultrasound after microbubble-based contrast agent injection. METHODS: From a series of 253 consecutive lesions that were indeterminate on baseline ultrasound and then scanned after injection of air-filled microbubble contrast agent, 65 focal liver lesions were retrospectively selected on the basis of a diagnosis of liver hemangioma on multiphase contrast-enhanced computed tomography (n = 23), magnetic resonance imaging (n = 27), or histology (n = 15). Each lesion was scanned during arterial phase (30 s after microbubble injection) and late phase (5 min after injection). …
Contrast-enhanced transcranial Doppler ultrasonography in the diagnosis of brain death
2013
The diagnosis of brain death (BD) is based on clinical criteria including deep coma, brain stem areflexia and apnoea. Depending on different local guidelines, confirmatory technical tests are sometimes mandatory.1 Since the 1990s, transcranial Doppler sonography (TCD) has found its place in these circumstances and fulfils most of the criteria of an ‘ideal test’ in confirming BD. To confirm intracranial circulatory arrest (CA) with Doppler sonography, typical flow patterns must be recorded in bilateral intracranial and extracranial brain-supplying arteries.2 A completely absent intracranial flow signal is not a reliable sign to determine CA because this can be due to transmission problems. I…
Analysis of Internal Jugular Vein Insufficiency—A Comparison of Two Ultrasound Methods
2006
Abstract Jugular venous valve insufficiency is a contributing factor to different pathologic conditions. For assessment of insufficiency, two ultrasound techniques have been developed, that are based on very different methodology (direct Doppler assessment versus air contrast ultrasound venography [ACUV]). This study was conducted to compare these two methods to improve comparability of existing studies and diagnostic accuracy in future studies. The function of 40 valves was determined in 20 individuals during a Valsalva maneuver. For direct Doppler assessment, valvular competence was assessed on basis of Doppler recordings, following recently established criteria. Valvular insufficiency in…
Hepatic focal nodular hyperplasia: contrast-enhanced ultrasound findings with emphasis on lesion size, depth and liver echogenicity
2010
To correlate contrast-enhanced ultrasound (CEUS) findings of hepatic focal nodular hyperplasia (FNH) with lesion size, depth and liver echogenicity and to compare CEUS with baseline US. Two radiologists evaluated baseline US and CEUS examinations of 92 FNHs (mean size: 3.1 +/- 1.7 cm) in 71 patients (59 women and 12 men) to detect the "spoke-wheel" sign, central scar and feeding vessel. The FNHs were grouped and analysed by dimension, depth and liver echogenicity. At least one sign could be detected at CEUS in 27 out of 36 (75%) FNHs larger than 3 cm and in 17 out of 56 (30%) FNH measuring 3 cm or less (p 0.05) as well as between CEUS or baseline US/CD with regard to lesion size, depth or l…
Left ventricular volume determination using Albunex.
1996
The aim of this study was to assess the ability of intravenous injection of Albunex to improve left ventricular volume determination in patients with various cardiac diseases. It is conceivable that the intravenous injection of microbubbles could improve echocardiographic left ventricular border delineation leading to improved interobserver variability. Echocardiograms were obtained during simultaneous intravenous injection of 0.08 and 0.12 ml/kg Albunex (four-chamber view). Within 6 hours after the recording of the contrast echocardiograms routine left heart angiography was performed. Volumes were measured using the slice method in native and contrast echocardiograms as well as in the angi…
Characterization of benign hepatic tumors arising in fatty liver with SonoVue and pulse inversion US.
2007
Background: We describe the spectrum of contrast-enhancement patterns of benign hepatic tumors arising in fatty liver on contrast-enhanced ultrasound (US). Methods: Sixteen patients (12 women and four men) with 27 benign hepatic tumors (17 hemangiomas, eight focal nodular hyperplasias, and two hepatocellular adenomas) arising in fatty liver underwent baseline and pulse inversion US after administration of SonoVue. Two experienced radiologists evaluated baseline echogenicity and dynamic enhancement pattern of each lesion in comparison with adjacent liver parenchyma. Results: After administration of SonoVue, in the arterial phase 13 of 17 hemangiomas showed peripheral globular enhancement and…