824 resultados para Ultrasound (US)


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Musculoskeletal ultrasonography (US) is an established and validated imaging technique in rheumatology. Ultrasonography is able to directly visualize soft tissue pathologies such as synovial tissue changes. Pathological findings in superficial cartilage, bone lesions and synovial tissue changes in the context of rheumatoid arthritis, spondyloarthritis or crystal arthropathies may only be seen by sonography or detected earlier by ultrasonography compared to conventional imaging techniques. The activity of an inflammatory arthropathy can be visualized using Doppler and power Doppler US. US is helpful in the detection of early inflammatory changes, particularly in patients with undifferentiated arthritis and/or unremarkable conventional radiography. In addition to diagnosis in early arthritis and monitoring of therapy in rheumatoid arthritis, sonography is able to detect pivotal pathologies in spondyloarthritis and crystal deposition diseases such as gout, pseudogout and apatite deposition disease. Ultrasound-guided diagnostic and therapeutic interventions are characterized by their excellent accuracy and improvement of clinical effectiveness compared to unguided procedures. In conclusion, ultrasonography plays a pivotal role in the assessment and monitoring of therapy in rheumatic diseases.

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To document the current state of musculoskeletal US (MSUS) training and extent of implementation among rheumatologists in the member countries of EULAR.

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Radiofrequency neurotomy is a recognized treatment for cervical zygapophysial joint pain. In several studies, the method has provided complete pain relief in 60-70% of the patients for approximately 9 months. The validated technique has the disadvantage of procedural times of 2-4 hours because several lesions are performed to take into account the variable nerve course. We tested the hypothesis that ultrasound localization of the nerves would enable us to reduce the number of lesions performed, while reaching the benchmark of at least 80% pain relief in 80% of patients with a median duration of 35 weeks, as achieved by a previous investigation using the standard method.

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To document the practice and training opportunities of US-guided arthrocentesis and joint injection (UGAJ) among rheumatologists in the member countries of the European League Against Rheumatism (EULAR).

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The purpose of this study was to demonstrate the improvement in diagnostic quality and diagnostic accuracy of SonoVue microbubble contrast-enhanced ultrasound (CE-US) versus unenhanced ultrasound imaging during the investigation of extracranial carotid or peripheral arteries. 82 patients with suspected extracranial carotid or peripheral arterial disease received four SonoVue doses (0.3 ml, 0.6 ml, 1.2 ml and 2.4 ml) with Doppler ultrasound performed before and following each dose. Diagnostic quality of the CE-US examinations was evaluated off-site for duration of clinically useful contrast enhancement, artefact effects and percentage of examinations converted from non-diagnostic to diagnostic. Accuracy, sensitivity and specificity were assessed as agreement of CE-US diagnosis evaluated by an independent panel of experts with reference standard modality. The median duration of clinically useful signal enhancement significantly increased with increasing SonoVue doses (p< or =0.002). At the dose of 2.4 ml of SonoVue, diagnostic quality evaluated as number of inconclusive examinations significantly improved, falling from 40.7% at baseline down to 5.1%. Furthermore, SonoVue significantly (p<0.01) increased the accuracy, sensitivity and specificity of assessment of disease compared with baseline ultrasound. SonoVue increases the diagnostic quality of Doppler images and improves the accuracy of both spectral and colour Doppler examinations of extracranial carotid or peripheral arterial disease.

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OBJECTIVE: To assess the response of RA patients to rituximab (RTX) treatment using a sensitive imaging technique for synovitis. METHODS: Twenty-three RA patients were treated with two 1000-mg infusions of the B-cell depleting antibody, RTX, in an observational protocol. Clinical response was assessed by the European League Against Rheumatism (EULAR) response criteria. High-resolution grey-scale and colour-coded power Doppler (PD) ultrasonography was performed at baseline and 6 months after RTX. The second to fifth MCP and PIP joints were bilaterally examined with joints in a neutral 0 position from a palmar view and scored from 0 to 3. RESULTS: Median disease activity score (DAS28) improved from 5.03 to 3.56 (P = 0.001), which corresponded to a EULAR moderate response in 11 of 23 patients and a EULAR good response in another 6 patients. Improved control of disease activity by RTX was also indicated by tapering of median daily corticosteroid doses from 10 to 5 mg, without flare ups. Mean grey-scale scores correlated with the swollen joint count at baseline (r = 0.484, P = 0.022) and month 6 (r = 0.519, P = 0.011). Mean grey-scale scores improved upon RTX from a 0.90 median (range 0.13-1.87) to 0.75 (range 0.19-1.50, P = 0.023). Frequency of PD positive joints was low (6.1%) at baseline and did not significantly change following RTX treatment. CONCLUSIONS: High-resolution grey-scale ultrasonography (US) examination confirmed reduced synovial hyperplasia, but the applied PD method displayed no significant changes. Therefore, only grey-scale US is recommended in follow-up examinations after RTX treatment.

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The efficacy of everolimus with reduced cyclosporine in de novo heart transplant patients has been demonstrated convincingly in randomized studies. Moreover, everolimus-based immunosuppression in de novo heart transplant recipients has been shown in two randomized trials to reduce the increase in maximal intimal thickness based on intravascular ultrasound, indicating attenuation of cardiac allograft vasculopathy (CAV). Randomized trials of everolimus in de novo heart transplantation have also consistently shown reduced cytomegalovirus infection versus antimetabolite therapy. In maintenance heart transplantation, conversion from calcineurin inhibitors to everolimus has demonstrated a sustained improvement in renal function. In de novo patients, a renal benefit may only be achieved if there is an adequate reduction in exposure to calcineurin inhibitor therapy. Delayed introduction of everolimus may be appropriate in patients at high risk of wound healing complications, e.g. diabetic patients or patients with ventricular assist device. The current evidence base suggests that the most convincing reasons for use of everolimus from the time of heart transplantation are to slow the progression of CAV and to lower the risk of cytomegalovirus infection. A regimen of everolimus with reduced-exposure calcineurin inhibitor and steroids in de novo heart transplant patients represents a welcome addition to the therapeutic armamentarium.

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INTRODUCTION: Cigarette smoking during pregnancy is associated with poor maternal and child health outcomes. Effective interventions to increase smoking cessation rates are needed particularly for pregnant women unable to quit in their first trimester. Real-time ultrasound feedback focused on potential effects of smoking on the fetus may be an effective treatment adjunct, improving smoking outcomes. METHODS: A prospective randomized trial was conducted to evaluate the efficacy of a smoking cessation intervention consisting of personalized feedback during ultrasound plus motivational interviewing-based counseling sessions. Pregnant smokers (N = 360) between 16 and 26 weeks of gestation were randomly assigned to one of three groups: Best Practice (BP) only, Best Practice plus ultrasound feedback (BP+US), or Motivational Interviewing-based counseling plus ultrasound feedback (MI+US). Assessments were conducted at baseline and end of pregnancy (EOP). RESULTS: Analyses of cotinine-verified self-reported smoking status at EOP indicated that 10.8% of the BP group was not smoking at EOP; 14.2% in the BP+US condition and 18.3% who received MI+US were abstinent, but differences were not statistically significant. Intervention effects were found conditional upon level of baseline smoking, however. Nearly 34% of light smokers (< or =10 cigarettes/day) in the MI+US condition were abstinent at EOP, followed by 25.8% and 15.6% in the BP+US and BP conditions, respectively. Heavy smokers (>10 cigarettes/day) were notably unaffected by the intervention. DISCUSSION: Future research should confirm benefit of motivational interviewing plus ultrasound feedback for pregnant light smokers and explore mechanisms of action. Innovative interventions for pregnant women smoking at high levels are sorely needed.

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Purpose: Congenital uterine anomalies often remain asymptomatic until they cause problems, for example during pregnancy. We studied the diagnostic aspects of two- and three-dimensional ultrasound and MRI. Materials and Methods: 63 women referred for suspected uterine anomalies were studied: In the first group (until July 2008) with 2 D-US and MRI, in the second group (from August 2008) additionally with 3 D-US; these women also had diagnostic or therapeutic operative confirmation. In the third group, only 3D-US was used. Results: In all women 3D-US was possible and successful. The most common anomaly was a subseptate uterus, while a septate uterus was less frequent, and uterus bicornis (unicollis) and uterus didelphys (bicornis bicollis) were rare. The women in the first two groups all underwent at least diagnostic hysteroscopy, and some (subseptate or septate uterus) underwent operative hysteroscopy. After preoperative volume imaging, laparoscopies were required less often. 3D-US diagnoses as judged by intraoperative findings were correct in 100 % of cases, while the MRI diagnoses in the same group were correct in only 7/13 cases. Conclusion: Since the introduction of volume imaging (MRI, later 3 D-US), laparoscopy during hysteroscopic septum resection was not necessary in the majority of cases. 3D-US brings the diagnostics of uterine anomalies back into the hands of the gynecologist and can provide the gynecological surgeon with a higher subjective degree of certainty during operative hysteroscopy.

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Background: Infraclavicular brachial plexus nerve blockade (ICNB) is a very common anesthetic procedure performed for upper extremity surgery at the elbow and distally, however the rate of adequate analgesia is variable among patients. Ultrasound guidance (US) has not been demonstrated to increase the success rate of ICNB when compared to nerve stimulator (NS) guidance. Combined US and NS guided ICNB have not been reported, although there is a call for more trials comparing the two techniques. This study was performed to observe if a specific anatomic region near the axillary artery of the brachial plexus identified by finger flexion with nerve stimulation results in improved postoperative analgesia. Method: Patients undergoing elective elbow arthroplasty received a postoperative ICNB. The angle of the nerve stimulator needle tip and the radial distance from the center of the arterial lumen at which an optimal finger flexion twitch response was observed were measured with ultrasound imaging. Pain scores and postoperative opioid dosages on discharge from the post anesthesia care unit and at 24 hours after surgery were recorded. Results: 11 patients enrolled in this study. Adequate finger flexion response to nerve stimulation that resulted in complete analgesia was more frequently observed when the needle was located in the postero-superior quadrant in relation to the axillary artery. Identifying a specific point near the brachial plexus in relation to the artery that consistently provides superior analgesia is desirable and would lead to improved analgesia and faster onset time of nerve blockade and would reduce the need for other approaches for brachial plexus blockade with their associated disadvantages.

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Purpose: To compare corneal thickness measurements using Orbscan II (OII) and ultrasonic (US) pachymetry in normal and in keratoconic eyes. Setting: Eye Department, Heartlands and Solihull NHS Trust, Birmingham, United Kingdom. Methods: Central corneal thickness (CCT) was measured by means of OII and US pachymetry in 1 eye of 72 normal subjects and 36 keratoconus patients. The apical corneal thickness (ACT) in keratoconus patients was also evaluated using each method. The mean of the difference, standard deviation (SD), and 95% limits of agreement (LoA = mean ± 2 SD), with and without applying the default linear correction factor (LCF), were determined for each sample. The Student t test was used to identify significant differences between methods, and the correlation between methods was determined using the Pearson bivariate correlation. Bland-Altman analysis was performed to confirm that the results of the 2 instruments were clinically comparable. Results: In normal eyes, the mean difference (± 95% LoA) in CCT was 1.04 μm ± 68.52 (SD) (P>.05; r = 0.71) when the LCF was used and 46.73 ± 75.40 μm (P = .0001; r = 0.71) without the LCF. In keratoconus patients, the mean difference (± 95% LoA) in CCT between methods was 42.46 ± 66.56 μm (P<.0001: r = 0.85) with the LCF, and 2.51 ± 73.00 μm (P>.05: r = 0.85) without the LCF. The mean difference (± 95% LoA) in ACT for this group was 49.24 ± 60.88 μm (P<.0001: r = 0.89) with the LCF and 12.71 ± 68.14 μm (P = .0077; r = 0.89) when the LCF was not used. Conclusions: This study suggests that OII and US pachymetry provide similar readings for CCT in normal subjects when an LCF is used. In keratoconus patients, OII provides a valid clinical tool for the noninvasive assessment of CCT when the LCF is not applied. © 2004 ASCRS and ESCRS.

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We report a characterization of the acoustic sensitivity of microstructured polymer optical fiber interferometric sensors at ultrasonic frequencies from 100kHz to 10MHz. The use of wide-band ultrasonic fiber optic sensors in biomedical ultrasonic and optoacoustic applications is an open alternative to conventional piezoelectric transducers. These kind of sensors, made of biocompatible polymers, are good candidates for the sensing element in an optoacoustic endoscope because of its high sensitivity, its shape and its non-brittle and non-electric nature. The acoustic sensitivity of the intrinsic fiber optic interferometric sensors depends strongly of the material which is composed of. In this work we compare experimentally the intrinsic ultrasonic sensitivities of a PMMA mPOF with other three optical fibers: a singlemode silica optical fiber, a single-mode polymer optical fiber and a multimode graded-index perfluorinated polymer optical fiber. © 2014 SPIE.

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Polymer optical fibre (POF) is a relatively new and novel technology that presents an innovative approach for ultrasonic endoscopic applications. Currently, piezo electric transducers are the typical detectors of choice, albeit possessing a limited bandwidth due to their resonant nature and a sensitivity that decreases proportionally to their size. Optical fibres provide immunity from electromagnetic interference and POF in particular boasts more suitable physical characteristics than silica optical fibre. The most important of these are lower acoustic impedance, a reduced Young's Modulus and a higher acoustic sensitivity than single-mode silica fibre at both 1 MHz and 10 MHz. POF therefore offers an interesting alternative to existing technology. Intrinsic fibre structures such as Bragg gratings and Fabry-Perot cavities may be inscribed into the fibre core using UV lasers. These gratings are a modulation of the refractive index of the fibre core and provide the advantages of high reflectivity, customisable bandwidth and point detection. We present a compact in fibre ultrasonic point detector based upon a POF Bragg grating (POFBG) sensor. We demonstrate that the detector is capable of leaving a laboratory environment by using connectorised fibre sensors and make a case for endoscopic ultrasonic detection through use of a mounting structure that better mimics the environment of an endoscopic probe. We measure the effects of water immersion upon POFBGs and analyse the ultrasonic response for 1, 5 and 10 MHz.

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Advanced oxidation processes (AOPs) are modern methods using reactive hydroxyl radicals for the mineralization of organic pollutants into simple inorganic compounds, such as CO2 and H2O. Among AOPs electrochemical oxidation (EO) is a method suitable for coloured and turbid wastewaters. The degradation of pollutants occurs on electrocatalytic electrodes. The majority of electrodes contain in their structure either expensive materials (diamond and Pt-group metals) or are toxic for the environment compounds (Sb or Pb). One of the main disadvantages of electrochemical method is the polarization and contamination of electrodes due to the deposition of reaction products on their surface, which results in diminishing of the process efficiency. Ultrasound combined with the electrochemical degradation process eliminates electrode contamination because of the continuous mechanical cleaning effect produced by the formation and collapse of acoustic cavitation bubbles near to the electrode surface. Moreover, high frequency ultrasound generates hydroxyl radicals at water sonolysis. Ultrasound-assisted EO is a non-selective method for oxidation of different organic compounds with high degradation efficiencies. The aim of this research was to develop novel sustainable and cost-effective electrodes working as electrocatalysts and test their activity in electrocatalytic oxidation of organic compounds such as dyes and organic acids. Moreover, the goal of the research was to enhance the efficiency of electrocatalytic degradation processes by assisting it with ultrasound in order to eliminate the main drawbacks of a single electrochemical oxidation such as electrodes polarization and passivation. Novel Ti/Ta2O5-SnO2 electrodes were developed and found to be electrocatalytically active towards water (with 5% Ta content, 10 oxide film layers) and organic compounds oxidation (with 7.5% Ta content, 8 oxide film layers) and therefore these electrodes can be applicable in both environmental and energy fields. The synergetic effect of combined electrolysis and sonication was shown while conducting sonoelectrochemical (EO/US) degradation of methylene blue (MB) and formic acid (FA). Complete degradation of MB and FA was achieved after 45 and 120 min of EO/US process respectively in neutral media. Mineralization efficiency of FA over 95% was obtained after 2 h of degradation using high frequency ultrasound (381, 863, 1176 kHz) combined with 9.1 mA/cm2 current density. EO/US degradation of MB provided over 75% mineralization in 8 h. High degradation kinetic rates and mineralization efficiencies of model pollutants obtained in EO/US experiments provide the preconditions for further extrapolation of this treatment method to pilot scale studies with industrial wastewaters.

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Unpredicted difficult intubation can have severe consequences, and it is a significant source of morbidity and mortality. Although recent studies indicate that specific ultrasonography (US) measurements may be predictors of difficult laryngoscopy, their use is still limited, and its quantification is missing. The purpose of this prospective observational study is to evaluate the use of US-measured distance from skin to epiglottis (DSE) for difficult laryngoscopy prediction.