125 resultados para INTRAVASCULAR ULTRASOUND ELASTOGRAPHY
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Purpose To investigate the differences in viscoelastic properties between normal and pathologic Achilles tendons ( AT Achilles tendon s) by using real-time shear-wave elastography ( SWE shear-wave elastography ). Materials and Methods The institutional review board approved this study, and written informed consent was obtained from 25 symptomatic patients and 80 volunteers. One hundred eighty ultrasonographic (US) and SWE shear-wave elastography studies of AT Achilles tendon s without tendonopathy and 30 studies of the middle portion of the AT Achilles tendon in patients with tendonopathy were assessed prospectively. Each study included data sets acquired at B-mode US (tendon morphology and cross-sectional area) and SWE shear-wave elastography (axial and sagittal mean velocity and relative anisotropic coefficient) for two passively mobilized ankle positions. The presence of AT Achilles tendon tears at B-mode US and signal-void areas at SWE shear-wave elastography were noted. Results Significantly lower mean velocity was shown in tendons with tendonopathy than in normal tendons in the relaxed position at axial SWE shear-wave elastography (P < .001) and in the stretched position at sagittal (P < .001) and axial (P = .0026) SWE shear-wave elastography . Tendon softening was a sign of tendonopathy in relaxed AT Achilles tendon s when the mean velocity was less than or equal to 4.06 m · sec(-1) at axial SWE shear-wave elastography (sensitivity, 54.2%; 95% confidence interval [ CI confidence interval ]: 32.8, 74.4; specificity, 91.5%; 95% CI confidence interval : 86.3, 95.1) and less than or equal to 5.70 m · sec(-1) at sagittal SWE shear-wave elastography (sensitivity, 41.7%; 95% CI confidence interval : 22.1, 63.3; specificity, 81.8%; 95% CI confidence interval : 75.3, 87.2) and in stretched AT Achilles tendon s, when the mean velocity was less than or equal to 4.86 m · sec(-1) at axial SWE shear-wave elastography (sensitivity, 66.7%; 95% CI confidence interval : 44.7, 84.3; specificity, 75.6%; 95% CI confidence interval : 68.5, 81.7) and less than or equal to 14.58 m · sec(-1) at sagittal SWE shear-wave elastography (sensitivity, 58.3%; 95% CI confidence interval : 36.7, 77.9; specificity, 83.5%; 95% CI confidence interval : 77.2, 88.7). Anisotropic results were not significantly different between normal and pathologic AT Achilles tendon s. Six of six (100%) partial-thickness tears appeared as signal-void areas at SWE shear-wave elastography . Conclusion Whether the AT Achilles tendon was relaxed or stretched, SWE shear-wave elastography helped to confirm and quantify pathologic tendon softening in patients with tendonopathy in the midportion of the AT Achilles tendon and did not reveal modifications of viscoelastic anisotropy in the tendon. Tendon softening assessed by using SWE shear-wave elastography appeared to be highly specific, but sensitivity was relatively low. © RSNA, 2014.
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In three-dimensional (3D) coronary magnetic resonance angiography (MRA), the in-flow contrast between the coronary blood and the surrounding myocardium is attenuated as compared to thin-slab two-dimensional (2D) techniques. The application of a gadolinium (Gd)-based intravascular contrast agent may provide an additional source of signal and contrast by reducing T(1blood) and supporting the visualization of more distal or branching segments of the coronary arterial tree. In six healthy adults, the left coronary artery (LCA) system was imaged pre- and postcontrast with a 0.075-mmol/kg bodyweight dose of the intravascular contrast agent B-22956. For imaging, an optimized free-breathing, navigator-gated and -corrected 3D inversion recovery (IR) sequence was used. For comparison, state-of-the-art baseline 3D coronary MRA with T(2) preparation for non-exogenous contrast enhancement was acquired. The combination of IR 3D coronary MRA, sophisticated navigator technology, and B-22956 allowed for an extensive visualization of the LCA system. Postcontrast, a significant increase in both the signal-to-noise ratio (SNR; 46%, P < 0.05) and contrast-to-noise ratio (CNR; 160%, P < 0.01) was observed, while vessel sharpness of the left anterior descending (LAD) artery and the left coronary circumflex (LCX) were improved by 20% (P < 0.05) and 18% (P < 0.05), respectively.
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Ultrasound (US) has become a useful tool in the detection of early disease, differential diagnosis, guidance of treatment decisions and treatment monitoring of rheumatoid arthritis (RA). In 2008, the Swiss Sonography in Arthritis and Rheumatism (SONAR) group was established to promote the use of US in inflammatory arthritis in clinical practice. A scoring system was developed and taught to a large number of Swiss rheumatologists who already contributed to the Swiss Clinical Quality Management (SCQM) database, a national patient register. This paper intends to give a Swiss consensus about best clinical practice recommendations for the use of US in RA on the basis of the current literature knowledge and experience with the Swiss SONAR score. Literature research was performed to collect data on current evidence. The results were discussed among specialists of the Swiss university centres and private practice, following a structured procedure. Musculoskelatal US was found to be very helpful in establishing the diagnosis and monitoring the evolution of RA, and to be a reliable tool if used by experienced examiners. It influences treatment decisions such as continuing, intensifying or stepping down therapy. The definite modalities of integrating US into the diagnosis and monitoring of RA treatments will be defined within a few years. There are, however, strong arguments to use US findings as of today in daily clinical care. Some practical recommendations about the use of US in RA, focusing on the diagnosis and the use of the SONAR score, are proposed.
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This nested case-control analysis of a Swiss ambulatory cohort of elderly women assessed the discriminatory power of urinary markers of bone resorption and heel quantitative ultrasound for non-vertebral fractures. The tests all discriminated between cases and controls, but combining the two strategies yielded no additional relevant information. INTRODUCTION: Data are limited regarding the combination of bone resorption markers and heel quantitative bone ultrasound (QUS) in the detection of women at risk for fracture. METHODS: In a nested case-control analysis, we studied 368 women (mean age 76.2 +/- 3.2 years), 195 with low-trauma non-vertebral fractures and 173 without, matched for age, BMI, medical center, and follow-up duration, from a prospective study designed to predict fractures. Urinary total pyridinolines (PYD) and deoxypyridinolines (DPD) were measured by high performance liquid chromatography. All women underwent bone evaluations using Achilles+ and Sahara heel QUS. RESULTS: Areas under the receiver operating-characteristic curve (AUC) for discriminative models of the fracture group, with 95% confidence intervals, were 0.62 (0.56-0.68) and 0.59 (0.53-0.65) for PYD and DPD, and 0.64 (0.58-0.69) and 0.65 (0.59-0.71) for Achilles+ and Sahara QUS, respectively. The combination of resorption markers and QUS added no significant discriminatory information to either measurement alone with an AUC of 0.66 (0.60-0.71) for Achilles+ with PYD and 0.68 (0.62-0.73) for Sahara with PYD. CONCLUSIONS: Urinary bone resorption markers and QUS are equally discriminatory between non-vertebral fracture patients and controls. However, the combination of bone resorption markers and QUS is not better than either test used alone.
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This study aimed to assess application of ultrasound (US) combined with microbubbles (MB) to transfect the ciliary muscle of rat eyes. Reporter DNA plasmids encoding for Gaussia luciferase, β-galactosidase or the green fluorescent protein (GFP), alone or mixed with 50% Artison MB, were injected into the ciliary muscle, with or without US exposure (US set at 1 MHz, 2 W/cm(2), 50% duty cycle for 2 min). Luciferase activity was measured in ocular fluids at 7 and 30 days after sonoporation. At 1 week, the US+MB treatment showed a significant increase in luminescence compared with control eyes, injected with plasmid only, with or without MB (×2.6), and, reporter proteins were localized in the ciliary muscle by histochemical analysis. At 1 month, a significant decrease in luciferase activity was observed in all groups. A rise in lens and ciliary muscle temperature was measured during the procedure but did not result in any observable or microscopic damages at 1 and 8 days. The feasibility to transfer gene into the ciliary muscle by US and MB suggests that sonoporation may allow intraocular production of proteins for the treatment of inflammatory, angiogenic and/or degenerative retinal diseases.
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For radiotherapy treatment planning of retinoblastoma inchildhood, Computed Tomography (CT) represents thestandard method for tumor volume delineation, despitesome inherent limitations. CT scan is very useful inproviding information on physical density for dosecalculation and morphological volumetric information butpresents a low sensitivity in assessing the tumorviability. On the other hand, 3D ultrasound (US) allows ahigh accurate definition of the tumor volume thanks toits high spatial resolution but it is not currentlyintegrated in the treatment planning but used only fordiagnosis and follow-up. Our ultimate goal is anautomatic segmentation of gross tumor volume (GTV) in the3D US, the segmentation of the organs at risk (OAR) inthe CT and the registration of both. In this paper, wepresent some preliminary results in this direction. Wepresent 3D active contour-based segmentation of the eyeball and the lens in CT images; the presented approachincorporates the prior knowledge of the anatomy by usinga 3D geometrical eye model. The automated segmentationresults are validated by comparing with manualsegmentations. Then, for the fusion of 3D CT and USimages, we present two approaches: (i) landmark-basedtransformation, and (ii) object-based transformation thatmakes use of eye ball contour information on CT and USimages.
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Introduction: A standardized three-dimensional ultrasonographic (3DUS) protocol is described that allows fetal face reconstruction. Ability to identify cleft lip with 3DUS using this protocol was assessed by operators with minimal 3DUS experience. Material and Methods: 260 stored volumes of fetal face were analyzed using a standardized protocol by operators with different levels of competence in 3DUS. The outcomes studied were: (1) the performance of post-processing 3D face volumes for the detection of facial clefts; (2) the ability of a resident with minimal 3DUS experience to reconstruct the acquired facial volumes, and (3) the time needed to reconstruct each plane to allow proper diagnosis of a cleft. Results: The three orthogonal planes of the fetal face (axial, sagittal and coronal) were adequately reconstructed with similar performance when acquired by a maternal-fetal medicine specialist or by residents with minimal experience (72 vs. 76%, p = 0.629). The learning curve for manipulation of 3DUS volumes of the fetal face corresponds to 30 cases and is independent of the operator's level of experience. Discussion: The learning curve for the standardized protocol we describe is short, even for inexperienced sonographers. This technique might decrease the length of anatomy ultrasounds and improve the ability to visualize fetal face anomalies.
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Supplementation of elderly institutionalized women with vitamin D and calcium decreased hip fractures and increased hip bone mineral density. Quantitative ultrasound (QUS) measurements can be performed in nursing homes, and easily repeated for follow-up. However, the effect of the correction of vitamin D deficiency on QUS parameters is not known. Therefore, 248 institutionalized women aged 62-98 years were included in a 2-year open controlled study. They were randomized into a treated group (n = 124), receiving 440 IU of vitamin D3 combined with 500 mg calcium (1250 mg calcium carbonate, Novartis) twice daily, and a control group (n = 124). One hundred and three women (42%), aged 84.5 +/- 7.5 years, completed the study: 50 in the treated group, 53 in the controls. QUS of the calcaneus, which measures BUA (broadband ultrasound attenuation) and SOS (speed of sound), and biochemical analysis were performed before and after 1 and 2 years of treatment. Only the results of the women with a complete follow-up were taken into account. Both groups had low initial mean serum 25-hydroxyvitamin D levels (11.9 +/- 1.2 and 11.7 +/- 1.2 micrograms/l; normal range 6.4-40.2 micrograms/l) and normal mean serum parathyroid hormone (PTH) levels (43.1 +/- 3.2 and 44.6 +/- 3.5 ng/l; normal range 10-70 ng/l, normal mean 31.8 +/- 2.3 ng/l). The treatment led to a correction of the metabolic disturbances, with an increase in 25-hydroxyvitamin D by 123% (p < 0.01) and a decrease in PTH by 18% (p < 0.05) and of alkaline phosphatase by 15% (p < 0.01). In the controls there was a worsening of the hypovitaminosis D, with a decrease of 25-hydroxyvitamin D by 51% (p < 0.01) and an increase in PTH by 51% (p < 0.01), while the serum calcium level decreased by only 2% (p < 0.01). After 2 years of treatment BUA increased significantly by 1.6% in the treated group (p < 0.05), and decreased by 2.3% in the controls (p < 0.01). Therefore, the difference in BUA between the treated subjects and the controls (3.9%) was significant after 2 years (p < 0.01). However, SOS decreased by the same amount in both groups (approximately 0.5%). In conclusion, BUA, but not SOS, reflected the positive effect on bone of supplementation with calcium and vitamin D3 in a population of elderly institutionalized women.
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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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We hypothesized that combining clinical risk factors (CRF) with the heel stiffness index (SI) measured via quantitative ultrasound (QUS) would improve the detection of women both at low and high risk for hip fracture. Categorizing women by risk score improved the specificity of detection to 42.4%, versus 33.8% using CRF alone and 38.4% using the SI alone. This combined CRF-SI score could be used wherever and whenever DXA is not readily accessible. INTRODUCTION AND HYPOTHESIS: Several strategies have been proposed to identify women at high risk for osteoporosis-related fractures; we wanted to investigate whether combining clinical risk factors (CRF) and heel QUS parameters could provide a more accurate tool to identify women at both low and high risk for hip fracture than either CRF or QUS alone. METHODS: We pooled two Caucasian cohorts, EPIDOS and SEMOF, into a large database named "EPISEM", in which 12,064 women, 70 to 100 years old, were analyzed. Amongst all the CRF available in EPISEM, we used only the ones which were statistically significant in a Cox multivariate model. Then, we constructed a risk score, by combining the QUS-derived heel stiffness index (SI) and the following seven CRF: patient age, body mass index (BMI), fracture history, fall history, diabetes history, chair-test results, and past estrogen treatment. RESULTS: Using the composite SI-CRF score, 42% of the women who did not report a hip fracture were found to be at low risk at baseline, and 57% of those who subsequently sustained a fracture were at high risk. Using the SI alone, corresponding percentages were 38% and 52%; using CRF alone, 34% and 53%. The number of subjects in the intermediate group was reduced from 5,400 (including 112 hip fractures) and 5,032 (including 111 hip fractures) to 4,549 (including 100 including fractures) for the CRF and QUS alone versus the combination score. CONCLUSIONS: Combining clinical risk factors to heel bone ultrasound appears to correctly identify more women at low risk for hip fracture than either the stiffness index or the CRF alone; it improves the detection of women both at low and high risk.
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The objective was to design a vascular phantom compatible with digital subtraction angiography, computerized tomography angiography, ultrasound and magnetic resonance angiography (MRA). Fiducial markers were implanted at precise known locations in the phantom to facilitate identification and orientation of plane views from three-dimensional (3-D) reconstructed images. A vascular conduit connected to tubing at the extremities of the phantom ran through an agar-based gel filling it. A vessel wall in latex was included around the conduit to avoid diffusion of contrast agents. Using a lost-material casting technique based on a low melting point metal, geometries of pathological vessels were modeled. During the experimental testing, fiducial markers were detectable in all modalities without distortion. No leak of gadolinium through the vascular wall was observed on MRA after 5 hours. Moreover, no significant deformation of the vascular conduit was noted during the fabrication process (confirmed by microtome slicing along the vessel). The potential use of the phantom for calibration, rescaling, and fusion of 3-D images obtained from the different modalities as well as its use for the evaluation of intra- and inter-modality comparative studies of imaging systems are discussed. In conclusion, the vascular phantom can allow accurate calibration of radiological imaging devices based on x-ray, magnetic resonance and ultrasound and quantitative comparisons of the geometric accuracy of the vessel lumen obtained with each of these methods on a given well defined 3-D geometry.
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Dual-energy X-ray absorptiometry (DXA) is commonly used in the care of patients for diagnostic classification of osteoporosis, low bone mass (osteopenia), or normal bone density; assessment of fracture risk; and monitoring changes in bone density over time. The development of other technologies for the evaluation of skeletal health has been associated with uncertainties regarding their applications in clinical practice. Quantitative ultrasound (QUS), a technology for measuring properties of bone at peripheral skeletal sites, is more portable and less expensive than DXA, without the use of ionizing radiation. The proliferation of QUS devices that are technologically diverse, measuring and reporting variable bone parameters in different ways, examining different skeletal sites, and having differing levels of validating data for association with DXA-measured bone density and fracture risk, has created many challenges in applying QUS for use in clinical practice. The International Society for Clinical Densitometry (ISCD) 2007 Position Development Conference (PDC) addressed clinical applications of QUS for fracture risk assessment, diagnosis of osteoporosis, treatment initiation, monitoring of treatment, and quality assurance/quality control. The ISCD Official Positions on QUS resulting from this PDC, the rationale for their establishment, and recommendations for further study are presented here.