| 1. |
- Braide, Magnus, 1955, et al.
(författare)
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Microvascular behavior and effects of sonazoid microbubbles in the cremaster muscle of rats after local administration.
- 2006
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Ingår i: Journal of ultrasound in medicine : official journal of the American Institute of Ultrasound in Medicine. - 0278-4297. ; 25:7, s. 883-90
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: The purpose of this study was to observe Sonazoid perfluorobutane microbubbles (GE Healthcare, Amersham, Buckinghamshire, England) in and their effects on the cremaster capillary microcirculation of rats. METHODS: Sonazoid (0.3 x 10(9) microbubbles in 0.5 mL) was observed by intravital microscopy in the cremaster muscle after retrograde administration into the femoral artery of 6 animals. Microbubble and microvessel diameters and blood flow velocities and the overall mean and SD of the 1-minute volume flow through the microscopic field were calculated from the 2 to 4 capillaries observed in the field of each animal. Fluorescein isothiocyanate-dextran leakage was used to assess extravasation after microbubble passage. RESULTS: seconds, respectively, before they were released and capillary flow normalized. No microbubble size changes, damming, or coalescence of bubbles and no changes in microvessel diameter or microvascular blood flow velocities, volume flow, or perfusion heterogeneity occurred during or after the passage of the Sonazoid suspension or the vehicle. No fluorescein isothiocyanate-dextran leakage was observed. CONCLUSIONS: The passage of Sonazoid bubbles at concentrations higher than those expected after intravenous administration of the Sonazoid did not durably impair microvascular perfusion, structural integrity, or macromolecular retention in the rat cremaster muscle. The duration of discrete capillary obstructions was short and in all cases comparable with that of naturally occurring leukocyte plugging.
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| 2. |
- Eisenbrey, John R., et al.
(författare)
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Parametric Subharmonic Imaging Using a Commercial Intravascular Ultrasound Scanner : An In Vivo Feasibility Study
- 2012
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Ingår i: Journal of ultrasound in medicine. - : American Institute for Ultrasound in Medicine. - 0278-4297 .- 1550-9613. ; 31:3, s. 361-371
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Tidskriftsartikel (refereegranskat)abstract
- Objectives— The feasibility of visualizing atherosclerotic plaque using parametric subharmonic intravascular ultrasound (IVUS) was investigated in vivo. Methods— Atherosclerosis was induced in the aorta of 2 rabbits. Following injection of Definity (Lantheus Medical Imaging, North Billerica, MA), radiofrequency IVUS signals were acquired at 40 MHz with a Galaxy IVUS scanner (Boston Scientific/Scimed, Natick, MA). Subharmonic imaging (SHI; receiving at 20 MHz) was performed offline by applying an 8-order equalization filter. Contrast-to-tissue ratios (CTRs) were computed for the vessel relative to the plaque area over 4 time points. Contrast-to-tissue ratios were also calculated for the plaque-tissue and vessel-tissue from 4 tissue regions of interest at 4 time points. Finally, parametric images showing the cumulative maximum intensity (CMI), time to peak, perfusion (PER), and time-integrated intensity (TII) were generated for the fundamental and subharmonic data sets, and CTR measurements were repeated. Results— Injection of the contrast agent resulted in improved delineation between plaque and the vessel lumen. Subharmonic imaging resulted in noticeable tissue suppression, although the intensity from the contrast agent was reduced. No improvement in the plaque to vessel lumen CTR was observed between the subharmonic and fundamental IVUS (2.1 ± 3.64 versus 2.2 ± 4.20; P = .5). However, the CTR for plaque-tissue was improved (11.8 ± 7.32 versus 9.9 ± 7.06; P < .0001) for SHI relative to fundamental imaging. Cumulative-maximum-intensity and TII maps of both fundamental and subharmonic data provided increased CTRs relative to nonparametric data sets (P < .002). Additionally, the CMI, PER, and TII of SHI IVUS showed significantly improved vessel-plaque CTRs relative to the fundamental (P < .04). Conclusions— Parametric SHI IVUS of atherosclerotic plaque is feasible and improves the visualization of the plaque.
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| 3. |
- Eriksson Crommert, Martin, 1974-, et al.
(författare)
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Can Sonography Be Used to Estimate Deep Abdominal Muscle Activation in Different Static Arm Positions While Standing?
- 2017
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Ingår i: Journal of ultrasound in medicine. - Laurel, USA : American Institute for Ultrasound in Medicine. - 0278-4297 .- 1550-9613. ; 36:1, s. 129-139
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: The aim of this study was to investigate whether sonography is a reliable tool for measuring deep abdominal muscle activation in different static arm positions while standing.Methods: Sonographic recordings were made of the transversus abdominis and obliquus internus abdominis in 4 different static arm positions that varied with regard to the postural demand and loading direction posed on the trunk. Ten nonconsecutive repetitions of each arm position were performed, and thickness measurements were made at 2 locations within each muscle. Reliability was analyzed by the generalizability theory; comparisons regarding thickness measurements were made by repeated-measures analyses of variance; and fascial sliding was analyzed by a 1-sample t test.Results: Averaged over all repetitions, arm positions, and the 2 measurement locations, the thickness measurements were highly reliable for both the obliquus internus abdominis and transversus abdominis. The transversus abdominis was thicker with shoulders flexed than with shoulders extended or arms above the head (P < .021) and with arms alongside the body compared with shoulders extended (P < .005). There was no thickness difference between arm positions for the obliquus internus abdominis (P = .059).Conclusions: The results indicate that sonographic recordings of the obliquus internus abdominis and transversus abdominis in different static arm positions while standing provide reliable measurements of muscle thickness. However, in light of previously reported electromyographic data, the results raise some concerns regarding the validity of using thickness measurements as proxies for muscle activation in positions that may induce passive muscle deformation.
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| 4. |
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| 5. |
- Grishenkov, Dmitry, 1983-, et al.
(författare)
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In search of the optimal ultrasound heart perfusion imaging platform
- 2015
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Ingår i: Journal of ultrasound in medicine. - : Wiley. - 0278-4297 .- 1550-9613. ; 34:9, s. 1599-1605
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Tidskriftsartikel (refereegranskat)abstract
- ObjectiveQuantification of the myocardial perfusion by contrast echocardiography (CEC) remains a challenge. Existing imaging phantoms used to evaluate the performance of ultrasound scanners do not comply with perfusion basics in the myocardium, where perfusion and motion are inherently coupled.MethodsTo contribute towards an improvement, we developed a CEC perfusion imaging platform based on isolated rat heart coupled to the ultrasound scanner. Perfusion was assessed using three different types of contrast agent: dextran-based Promiten®, phospholipid-shelled SonoVue®, and polymer-shelled MB-pH5-RT. The myocardial video-intensity was monitored over time from contrast administration to peak and two characteristic constants were calculated using exponential fit (A representing capillary volume and b representing inflow velocity).ResultsAcquired experimental evidence demonstrates that the application of all three types of contrast agent allow ultrasonic estimation of myocardial perfusion in the isolated rat heart. Video-intensity maps show that an increase in contrast concentration increases the late plateau values, A, mimicking increased capillary volume. Estimated values of the flow, proportional to Axb, increase when the pressure of the perfusate column increases from 80 to 110 cm of water. This finding is in agreement with the true values of the coronary flow increase measured by the flowmeter attached to the aortic cannula.ConclusionsThe described CEC perfusion imaging platform holds promise for standardized evaluation and optimization of ultrasound contrast perfusion imaging where real time inflow curves at low acoustic power semi-quantitatively reflect coronary flow.
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| 6. |
- Hallgren, C., et al.
(författare)
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Validating a Simplified Lung Ultrasound Protocol for Detection and Quantification of Pulmonary Edema in Patients With Chronic Kidney Disease Receiving Maintenance Hemodialysis
- 2023
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Ingår i: Journal of Ultrasound in Medicine. - : Wiley. - 0278-4297 .- 1550-9613. ; 42:9, s. 2013-2021
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Tidskriftsartikel (refereegranskat)abstract
- Objectives Pulmonary edema is a common clinical problem and lung ultrasound (LUS) presents an efficient method for evaluating this pathology. This study aims to investigate if a clinically efficient LUS protocol can quantify the level of extravascular lung fluid in patients receiving hemodialysis, and to develop a simplified B-line scoring system based on this protocol.Methods A simple 8-area LUS approach was used for the assessment of the extravascular fluid status in patients before, during, and after receiving hemodialysis. The LUS assessments were compared to the amount of removed fluid over time. To determine the best B-line score system, different scorings for each zone were tested in a linear mixed model with pseudo R-square model fit against removed fluid. The B-line score was further validated through correlations with changes in oxygen saturation, grade of dyspnea, and body weight over time.Results A total of 53 patients were included and examined on 108 hemodialysis occasions. Median fluid removal was 2.3 L. The B-line score model with best fit was a score of 0 points in a zone with 0 or 1 B-lines, 1 point with 2 or 3 B-lines, 2 points with 3 or more B-lines, and 3 points with any interstitial confluence. Using this B-line score, we found a significant association with amount of removed fluid, oxygen saturation, grade of dyspnea, and change in body weight.Conclusion A straightforward protocol for LUS and B-line score system was shown valid for quantification of pulmonary edema and fluid removal in hemodialysis patients. The scoring system developed here can be useful also in other patient groups, but this requires further validation.
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| 7. |
- Hilde, K., et al.
(författare)
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Fetal Thoracic Circumference and Lung Volume and Their Relation to Fetal Size and Pulmonary Artery Blood Flow
- 2022
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Ingår i: Journal of Ultrasound in Medicine. - : Wiley. - 0278-4297 .- 1550-9613. ; 41:4, s. 985-993
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Tidskriftsartikel (refereegranskat)abstract
- Objective Research on early origins of lung disease suggests the need for studying the relationships of thoracic and lung size with fetal size and pulmonary circulation. The primary aim of this study is therefore to explore the associations between fetal thoracic circumference, lung volume, and fetal size. We also aim to assess if lung volume and thoracic circumference are associated with fetal pulmonary artery blood flow velocity measures. Methods Cross-sectional assessment of singleton pregnancies from the general population (n = 447) at 30 gestational weeks (GW) was performed using ultrasound measurement of fetal thoracic circumference, lung volume, head and abdominal circumference, and femur length. We obtained Doppler blood flow velocity measures from the proximal branches of the fetal pulmonary artery. Associations between variables were studied using Pearson's correlation and multiple linear regression analyses. Results Both thoracic circumference and lung volume correlated with fetal size measures, ranging from r = 0.64 between thoracic circumference and abdominal circumference, to r = 0.28 between lung volume and femur length. Adjustment for gestational age, maternal nicotine use, pre-pregnancy body mass index, and fetal sex marginally influenced the associations with abdominal circumference. The correlations of thoracic circumference and lung volume with pulmonary artery blood flow velocity measures were weak (r <= 0.17). Conclusion We found moderate to low correlation between thoracic circumference, lung volume, and fetal size at 30 GW. The closest relationship was with the abdominal circumference. We found low correlations of thoracic circumference and lung volume with pulmonary artery blood flow velocity measures.
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| 8. |
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| 9. |
- Khosravi, Fariba, et al.
(författare)
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Scapular Upward Rotator Morphologic Characteristics in Individuals With and Without Forward Head Posture : A Case-Control Study
- 2019
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Ingår i: Journal of ultrasound in medicine. - : John Wiley & Sons. - 0278-4297 .- 1550-9613. ; 38:2, s. 337-345
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Tidskriftsartikel (refereegranskat)abstract
- Objectives There are several reports suggesting that forward head posture contributes to alterations in scapular kinematics and muscle activity, leading to the development of shoulder problems. Currently, it is unknown whether forward head posture alters the thickness of the scapular muscles. The aim of this study was to compare the thickness of the serratus anterior and upper and lower trapezius muscles at rest and during loaded isometric contractions in individuals with and without forward head posture. Methods Twenty individuals with forward head posture and 20 individuals with normal head posture participated in this case-control study. Three separate ultrasound images of the serratus anterior and upper and lower trapezius muscles were captured under 2 randomized conditions: at rest and during a loaded isometric contraction. Results The thickness of each muscle significantly increased from rest to the loaded isometric contraction (P?
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| 10. |
- Larsson, Anna-Karin, et al.
(författare)
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Parents’ Worried State of Mind When Fetal Ultrasound Shows an Unexpected Finding
- 2009
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Ingår i: Journal of ultrasound in medicine. - 0278-4297 .- 1550-9613. ; 28:12, s. 1663-1670
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Tidskriftsartikel (refereegranskat)abstract
- Objective. Most parents yearn for a second-trimester ultrasound examination and feel excitement about it, but some also worry about what the examination will show. According to prior research, using only generic instruments or specific questionnaires, anxiety decreases when the ultrasound findings are normal. The aim of this study was to compare parents’ worry (Parents’ Expectations, Experiences, and Reactions to Ultrasound [PEER-U] State of Mind Index) and sense of coherence before and after a routine second-trimester ultrasound examination when it showed normal or abnormal findings. Methods. A 1-year cohort study was performed at a Swedish university hospital. A total of 2049 parents who had their second-trimester ultrasound examinations there filled in a questionnaire consisting of 2 parts before and after the examinations. Results. Parents with normal ultrasound findings were less worried than parents with abnormal findings. The group with normal findings also showed less worry after the examination than before. A sex analysis showed similar patterns. Conclusions. Parents with abnormal ultrasound findings are more worried and anxious. The new instrument, the PEER-U State of Mind Index, not only measures parents’ worry but can also expose what influences their ultrasound examination experience.
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