160 resultados para Power Doppler ultrasound
em Université de Lausanne, Switzerland
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BACKGROUND: Angiographic studies suggest that acute vasospasm within 48 h of aneurysmal subarachnoid hemorrhage (SAH) predicts symptomatic vasospasm. However, the value of transcranial Doppler within 48 h of SAH is unknown. METHODS: We analyzed 199 patients who had at least 1 middle cerebral artery (MCA) transcranial Doppler examination within 48 h of SAH onset. Abnormal MCA mean blood flow velocity (mBFV) was defined as >90 cm/s. Delayed cerebral ischemia (DCI) was defined as clinical deterioration or radiological evidence of infarction due to vasospasm. RESULTS: Seventy-six patients (38%) had an elevation of MCA mBFV >90 cm/s within 48 h of SAH onset. The predictors of elevated mBFV included younger age (OR = 0.97 per year of age, p = 0.002), admission angiographic vasospasm (OR = 5.4, p = 0.009) and elevated white blood cell count (OR = 1.1 per 1,000 white blood cells, p = 0.003). Patients with elevated mBFV were more likely to experience a 10 cm/s fall in velocity at the first follow-up than those with normal baseline velocities (24 vs. 10%, p < 0.01), suggestive of resolving spasm. DCI developed in 19% of the patients. An elevated admission mBFV >90 cm/s during the first 48 h (adjusted OR = 2.7, p = 0.007) and a poor clinical grade (Hunt-Hess score 4 or 5, OR = 3.2, p = 0.002) were associated with a significant increase in the risk of DCI. CONCLUSION: Early elevations of mBFV correlate with acute angiographic vasospasm and are associated with a significantly increased risk of DCI. Transcranial Doppler ultrasound may be an early useful tool to identify patients at higher risk to develop DCI after SAH.
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Background/Purpose: Since the end of 2009, an ultrasound scoring call SONAR has been implemented for RA patients as a routine tool in the SCQM registry (Swiss Clinical Quality Management registry for rheumatic diseases). A cross-sectional evaluation of patients with active disease and clinical remission according to the DAS28ESR and the novel ACR/EULAR remission criteria from 2010 clearly indicated a good correlational external validity of synovial pathologies with clinical disease activity in RA (2012 EULAR meeting. Objective: of this study was to evaluate the sensitivity to change of B-mode and Power-Doppler scores in a longitudinal perspective along with the changes in DAS28ESR in two consecutive visits among the patients included in the SCQM registry Methods: All patients who had at least two SONAR scores and simultaneous DAS28ESR evaluations between December 2009 and June 2012 were included in this study. The data came from 20 different operators working mostly in hospitals but also in private practices, who had received a previous teaching over 3 days in a reference center. The SONAR score includes a semi-quantitative B mode and Power-Doppler evaluation of 22 joints from 0 to 3, maximum 66 points for each score. The selection of these 22 joints was done in analogy to a 28 joint count and further restricted to joint regions with published standard ultrasound images. Both elbows and wrist joints were dynamically scanned from the dorsal and the knee joints from a longitudinal suprapatellar view in flexion and in joint extension. The bilateral evaluation of the second to fifth metacarpophalangeal and proximal interphalangeal joints was done from a palmar view in full extension, and the Power-Doppler scoring from a dorsal view with hand and finger position in best relaxation. Results: From the 657 RA patients with at least one score performed, 128 RA patients with 2 or more consultations of DAS28ESR, and a complete SONAR data set could be included. The mean (SD) time between the two evaluations was 9.6 months (54). The mean (SD) DAS28ESR was: 3.5 (1.3) at the first visit and was significantly lower (mean 3.0, SD.2.0, p:_0.0001) at the second visit. The mean (SD) of the total B mode was 12 (9.5) at baseline and 9.6 (7.6) at follow-up (p_0.0004). The Power-Doppler score at entry was 2.9 (5.7) and 1.9 (3.6), at the second visit, p _0.0001. The Pearson r correlation between change in DAS28ESR and the B mode was 0.44 (95% CI: 0.29, 0.57, p_ 0.0001),and 0.35 (95% CI: 0.16, 0.50, p _ 0.0002) for the Power-Doppler score,. Clinical relevant change in DAS (_1.1) was associated with a change of total B mode score _3 in 23/32 patients and a change a Doppler score _0.5 in 19/26. Conclusion: This study confirms that the SONAR score is sensitive to change and provides a complementary method of assessing RA disease activity to the DAS that could be very useful in daily practice.
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OBJECTIVE: To evaluate the correlation between clinical measures of disease activity and a ultrasound (US) scoring system for synovitis applied by many different ultrasonographers in a daily routine care setting within the Swiss registry for RA (SCQM) and further to determine the sensitivity to change of this US Score. METHODS: One hundred and eight Swiss rheumatologists were trained in performing the Swiss Sonography in Arthritis and Rheumatism (SONAR) score. US B-mode and Power Doppler (PwD) scores were correlated with DAS28 and compared between the clinical categories in a cross-sectional cohort of patients. In patients with a second US (longitudinal cohort), we investigated if change in US score correlated with change in DAS and evaluated the responsiveness of both methods. RESULTS: In the cross-sectional cohort with 536 patients, correlation between the B-mode score and DAS28 was significant but modest (Pearson coefficient r=0.41, P<0.0001). The same was true for the PwD score (r=0.41, P<0.0001). In the longitudinal cohort with 183 patients we also found a significant correlation between change in B-mode and in PwD score with change in DAS28 (r=0.54, P<0.0001 and r=0.46, P<0.0001, respectively). Both methods of evaluation (DAS and US) showed similar responsiveness according to standardized response mean (SRM). CONCLUSIONS: The SONAR Score is practicable and was applied by many rheumatologists in daily routine care after initial training. It demonstrates significant correlations with the degree of as well as change in disease activity as measured by DAS. On the level of the individual, the US score shows many discrepancies and overlapping results exist.
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Objective: The treatment of choice in end-stage renal disease is¦transplantation.¦Hemodynamic disturbances can evoke graft loss, while early ultrasound¦identification of vascular problems improves outcome. The primary endpoint¦of this study was to identify differences in post-op complications with and¦without systematic, intraoperative Doppler ultrasound use. A secondary aim¦was to find a predictive resistance index limit which would show where surgical¦reintervention was necessary.¦Methods: Between Jan 2000 and Dec 2010, 108 renal transplants were¦performed from living donors at our institution. In group 1 (n = 67),¦intra-operative duplex ultrasound and intra-parenchymatous resistance index¦measurements assessed patients, while in group 2 (n = 41), no ultrasound was¦performed.¦Results. There were no inter-group differences in the overall post-op¦complication rate or in benefit to graft or patient survival with Doppler use,¦however, significantly more vascular complications (10% vs. 0%, p = 0·02) and¦more acute rejections (37% vs. 10%) occurred in group 2 than in group 1,¦respectively. When the resistance index was <0·5 intra-operatively, immediate¦surgical revision was undertaken to raise the index >0·6.¦Results: There were no inter-group differences in the overall post-op¦complication rate or in benefit to graft or patient survival with Doppler use,¦however, significantly more vascular complications (10% vs. 0%, p = 0·02) and¦more acute rejections (37% vs. 10%) occurred in group 2 than in group 1,¦respectively. When the resistance index was <0·5 intra-operatively, immediate¦surgical revision was undertaken to raise the index >0·6.¦Conclusion: This is the first report demonstrating benefits of systematic¦intraoperative Doppler ultrasound on post-operative complications in renal¦transplantation from living donors. Our results support surgical revision with a¦resistance index <0·5.
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This paper presents a review of different methods enabling the monitoring of cerebral function in neonatal and paediatric intensive care. EEG, evoked potentials, conventional radiological studies, computerized tomography, ultrasound, intracranial pressure measurements, nuclear magnetic resonance, Doppler ultrasound, radioisotope studies, angiography, infra-red spectral analysis and last, but not least, clinical examination produce information regarding the neurological state of the patient which must be critically analysed in order to ensure optimal management of the case. Unfortunately, and in spite of impressive progress in non-invasive monitoring of the cerebral function, we are still forced to make important medical and ethical decisions without precise information about the neurological state of our patients.
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We present the case of a young man with compression of both renal arteries by the crura of the diaphragm. Correct diagnosis of renal artery entrapment is difficult but crucial. The investigations rely on an high index of suspicion and include Doppler ultrasound and spiral computed tomography angiography, which permits visualization of the diaphragm and its relationships with the aorta. This pathology, unlike common renal artery stenoses, requires surgical decompression and sometimes aortorenal bypass graft.
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Radiological investigations using gadolinium or intravenous iodinated contrast products are used cautiously in patients suffering from chronic kidney disease because of their risk of acute kidney injury and systemic nephrogenic fibrosis. In this article, we review several radiological alternatives that can be useful to obtain renal anatomical and/or functional information in this patient population. The basic principles, indications, and advantages and limitations of Doppler ultrasound with measurement of the resistance index, contrast-enhanced ultrasound, and a technique called BOLD-MRI (blood-oxygenation level dependent-MRI) are discussed.
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PURPOSE: Continuous positive airway pressure (CPAP) is the gold standard treatment for obstructive sleep apnea. However, the physiologic impact of CPAP on cerebral blood flow (CBF) is not well established. Ultrasound can be used to estimate CBF, but there is no widespread accepted protocol. We studied the physiologic influence of CPAP on CBF using a method integrating arterial diameter and flow velocity (FV) measurements obtained for each vessel supplying blood to the brain. METHODS: FV and lumen diameter of the left and right internal carotid, vertebral, and middle cerebral arteries were measured using duplex Doppler ultrasound with and without CPAP at 15 cm H(2)O, applied in a random order. Transcutaneous carbon dioxide (PtcCO(2)), heart rate (HR), blood pressure (BP), and oxygen saturation were monitored. Results were compared with a theoretical prediction of CBF change based on the effect of partial pressure of carbon dioxide on CBF. RESULTS: Data were obtained from 23 healthy volunteers (mean ± SD; 12 male, age 25.1 ± 2.6 years, body mass index 21.8 ± 2.0 kg/m(2)). The mean experimental and theoretical CBF decrease under CPAP was 12.5 % (p < 0.001) and 11.9 % (p < 0.001), respectively. The difference between experimental and theoretical CBF reduction was not statistically significant (3.84 ± 79 ml/min, p = 0.40). There was a significant reduction in PtcCO(2) with CPAP (p = <0.001) and a significant increase in mean BP (p = 0.0017). No significant change was observed in SaO(2) (p = 0.21) and HR (p = 0.62). CONCLUSION: Duplex Doppler ultrasound measurements of arterial diameter and FV allow for a noninvasive bedside estimation of CBF. CPAP at 15 cm H(2)O significantly decreased CBF in healthy awake volunteers. This effect appeared to be mediated predominately through the hypocapnic vasoconstriction coinciding with PCO(2) level reduction. The results suggest that CPAP should be used cautiously in patients with unstable cerebral hemodynamics.
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CONTEXT: The incidence of localised prostate cancer is increasing worldwide. In light of recent evidence, current, radical, whole-gland treatments for organ-confined disease have being questioned with respect to their side effects, cancer control, and cost. Focal therapy may be an effective alternative strategy. OBJECTIVE: To systematically review the existing literature on baseline characteristics of the target population; preoperative evaluation to localise disease; and perioperative, functional, and disease control outcomes following focal therapy. EVIDENCE ACQUISITION: Medline (through PubMed), Embase, Web of Science, and Cochrane Review databases were searched from inception to 31 October 2012. In addition, registered but not yet published trials were retrieved. Studies evaluating tissue-preserving therapies in men with biopsy-proven prostate cancer in the primary or salvage setting were included. EVIDENCE SYNTHESIS: A total of 2350 cases were treated to date across 30 studies. Most studies were retrospective with variable standards of reporting, although there was an increasing number of prospective registered trials. Focal therapy was mainly delivered to men with low and intermediate disease, although some high-risk cases were treated that had known, unilateral, significant cancer. In most of the cases, biopsy findings were correlated to specific preoperative imaging, such as multiparametric magnetic resonance imaging or Doppler ultrasound to determine eligibility. Follow-up varied between 0 and 11.1 yr. In treatment-naïve prostates, pad-free continence ranged from 95% to 100%, erectile function ranged from 54% to 100%, and absence of clinically significant cancer ranged from 83% to 100%. In focal salvage cases for radiotherapy failure, the same outcomes were achieved in 87.2-100%, 29-40%, and 92% of cases, respectively. Biochemical disease-free survival was reported using a number of definitions that were not validated in the focal-therapy setting. CONCLUSIONS: Our systematic review highlights that, when focal therapy is delivered with intention to treat, the perioperative, functional, and disease control outcomes are encouraging within a short- to medium-term follow-up. Focal therapy is a strategy by which the overtreatment burden of the current prostate cancer pathway could be reduced, but robust comparative effectiveness studies are now required.
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Increased renal resistive index (RRI) has been recently associated with target organ damage and cardiovascular or renal outcomes in patients with hypertension and diabetes mellitus. However, reference values in the general population and information on familial aggregation are largely lacking. We determined the distribution of RRI, associated factors, and heritability in a population-based study. Families of European ancestry were randomly selected in 3 Swiss cities. Anthropometric parameters and cardiovascular risk factors were assessed. A renal Doppler ultrasound was performed, and RRI was measured in 3 segmental arteries of both kidneys. We used multilevel linear regression analysis to explore the factors associated with RRI, adjusting for center and family relationships. Sex-specific reference values for RRI were generated according to age. Heritability was estimated by variance components using the ASSOC program (SAGE software). Four hundred women (mean age±SD, 44.9±16.7 years) and 326 men (42.1±16.8 years) with normal renal ultrasound had mean RRI of 0.64±0.05 and 0.62±0.05, respectively (P<0.001). In multivariable analyses, RRI was positively associated with female sex, age, systolic blood pressure, and body mass index. We observed an inverse correlation with diastolic blood pressure and heart rate. Age had a nonlinear association with RRI. We found no independent association of RRI with diabetes mellitus, hypertension treatment, smoking, cholesterol levels, or estimated glomerular filtration rate. The adjusted heritability estimate was 42±8% (P<0.001). In a population-based sample with normal renal ultrasound, RRI normal values depend on sex, age, blood pressure, heart rate, and body mass index. The significant heritability of RRI suggests that genes influence this phenotype.
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This study examined the electromyographic, cerebral and muscle hemodynamic responses during intermittent isometric contractions of biceps brachii at 20, 40, and 60% of maximal voluntary contraction (MVC). Eleven volunteers completed 2 min of intermittent isometric contractions (12/min) at an elbow angle of 90° interspersed with 3 min rest between intensities in systematic order. Surface electromyography (EMG) was recorded from the right biceps brachii and near infrared spectroscopy (NIRS) was used to simultaneously measure left prefrontal and right biceps brachii oxyhemoglobin (HbO2), deoxyhemoglobin (HHb), and total hemoglobin (Hbtot). Transcranial Doppler ultrasound was used to measure middle cerebral artery velocity (MCAv) bilaterally. Finger photoplethysmography was used to record beat-to-beat blood pressure and heart rate. EMG increased with force output from 20 to 60% MVC (P < 0.05). Cerebral HbO2 and Hbtot increased while HHb decreased during contractions with differences observed between 60% vs. 40% and 20% MVC (P < 0.05). Muscle HbO2 decreased while HHb increased during contractions with differences being observed among intensities (P < 0.05). Muscle Hbtot increased from rest at 20% MVC (P < 0.05), while no further change was observed at 40 and 60% MVC (P > 0.05). MCAv increased from rest to exercise but was not different among intensities (P > 0.05). Force output correlated with the root mean square EMG and changes in muscle HbO2 (P < 0.05), but not changes in cerebral HbO2 (P > 0.05) at all three intensities. Force output declined by 8% from the 1st to the 24th contraction only at 60% MVC and was accompanied by systematic increases in RMS, cerebral HbO2 and Hbtot with a leveling off in muscle HbO2 and Hbtot. These changes were independent of alterations in mean arterial pressure. Since cerebral blood flow and oxygenation were elevated at 60% MVC, we attribute the development of fatigue to reduced muscle oxygen availability rather than impaired central neuronal activation.
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Precise focusing is essential for transcranial MRI-guided focused ultrasound (TcMRgFUS) to minimize collateral damage to non-diseased tissues and to achieve temperatures capable of inducing coagulative necrosis at acceptable power deposition levels. CT is usually used for this refocusing but requires a separate study (CT) ahead of the TcMRgFUS procedure. The goal of this study was to determine whether MRI using an appropriate sequence would be a viable alternative to CT for planning ultrasound refocusing in TcMRgFUS. We tested three MRI pulse sequences (3D T1 weighted 3D volume interpolated breath hold examination (VIBE), proton density weighted 3D sampling perfection with applications optimized contrasts using different flip angle evolution and 3D true fast imaging with steady state precision T2-weighted imaging) on patients who have already had a CT scan performed. We made detailed measurements of the calvarial structure based on the MRI data and compared those so-called 'virtual CT' to detailed measurements of the calvarial structure based on the CT data, used as a reference standard. We then loaded both standard and virtual CT in a TcMRgFUS device and compared the calculated phase correction values, as well as the temperature elevation in a phantom. A series of Bland-Altman measurement agreement analyses showed T1 3D VIBE as the optimal MRI sequence, with respect to minimizing the measurement discrepancy between the MRI derived total skull thickness measurement and the CT derived total skull thickness measurement (mean measurement discrepancy: 0.025; 95% CL (-0.22-0.27); p = 0.825). The T1-weighted sequence was also optimal in estimating skull CT density and skull layer thickness. The mean difference between the phase shifts calculated with the standard CT and the virtual CT reconstructed from the T1 dataset was 0.08 ± 1.2 rad on patients and 0.1 ± 0.9 rad on phantom. Compared to the real CT, the MR-based correction showed a 1 °C drop on the maximum temperature elevation in the phantom (7% relative drop). Without any correction, the maximum temperature was down 6 °C (43% relative drop). We have developed an approach that allows for a reconstruction of a virtual CT dataset from MRI to perform phase correction in TcMRgFUS.
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Meta-analysis of prospective studies shows that quantitative ultrasound of the heel using validated devices predicts risk of different types of fracture with similar performance across different devices and in elderly men and women. These predictions are independent of the risk estimates from hip DXA measures.Introduction Clinical utilisation of heel quantitative ultrasound (QUS) depends on its power to predict clinical fractures. This is particularly important in settings that have no access to DXA-derived bone density measurements. We aimed to assess the predictive power of heel QUS for fractures using a meta-analysis approach.Methods We conducted an inverse variance random effects meta-analysis of prospective studies with heel QUS measures at baseline and fracture outcomes in their follow-up. Relative risks (RR) per standard deviation (SD) of different QUS parameters (broadband ultrasound attenuation [BUA], speed of sound [SOS], stiffness index [SI], and quantitative ultrasound index [QUI]) for various fracture outcomes (hip, vertebral, any clinical, any osteoporotic and major osteoporotic fractures) were reported based on study questions.Results Twenty-one studies including 55,164 women and 13,742 men were included in the meta-analysis with a total follow-up of 279,124 person-years. All four QUS parameters were associated with risk of different fracture. For instance, RR of hip fracture for 1 SD decrease of BUA was 1.69 (95% CI 1.43-2.00), SOS was 1.96 (95% CI 1.64-2.34), SI was 2.26 (95%CI 1.71-2.99) and QUI was 1.99 (95% CI 1.49-2.67). There was marked heterogeneity among studies on hip and any clinical fractures but no evidence of publication bias amongst them. Validated devices from different manufacturers predicted fracture risks with similar performance (meta-regression p values > 0.05 for difference of devices). QUS measures predicted fracture with a similar performance in men and women. Meta-analysis of studies with QUS measures adjusted for hip BMD showed a significant and independent association with fracture risk (RR/SD for BUA = 1.34 [95%CI 1.22-1.49]).Conclusions This study confirms that heel QUS, using validated devices, predicts risk of different fracture outcomes in elderly men and women. Further research is needed for more widespread utilisation of the heel QUS in clinical settings across the world.