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Find video protocols related to scientific articles indexed in Pubmed.
Use and limitations of Cardiac Magnetic Resonance derived measures of aortic stiffness in patients after acute myocardial infarction.
Magn Reson Imaging
PUBLISHED: 08-27-2014
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Cardiac magnetic resonance (CMR) is a unique method to determine regional and local aortic stiffness parameters. Although various methods have been validated, there are no data in patients after acute ST-segment elevation myocardial infarction (STEMI). In the present study we assessed the feasibility of different CMR derived measures of aortic stiffness in patients after first acute STEMI for the first time.
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Processing of intentional and automatic number magnitudes in children born prematurely: evidence from fMRI.
Dev Neuropsychol
PUBLISHED: 08-05-2014
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This study examined the neural correlates of intentional and automatic number processing (indexed by number comparison and physical Stroop task, respectively) in 6- and 7-year-old children born prematurely. Behavioral results revealed significant numerical distance and size congruity effects. Imaging results disclosed (1) largely overlapping fronto-parietal activation for intentional and automatic number processing, (2) a frontal to parietal shift of activation upon considering the risk factors gestational age and birth weight, and (3) a task-specific link between math proficiency and functional magnetic resonance imaging (fMRI) signal within distinct regions of the parietal lobes-indicating commonalities but also specificities of intentional and automatic number processing.
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Diffusion-weighted magnetic resonance imaging for the diagnosis of patients with lumbar nerve root entrapment syndromes: results from a pilot study.
Eur Spine J
PUBLISHED: 05-07-2014
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Lumbar nerve root entrapment syndromes cause radicular signs and symptoms in the affected leg. The applicability of diffusion-weighted imaging (DWI) for the assessment of lower lumbar nerves (L4-S1) has been demonstrated. The purpose of this pilot study was to establish DWI reference data for the all lumbosacral nerve roots (L1-S1) in a healthy, asymptomatic study population and to determine its potential as a diagnostic tool for patients with lumbar radicular syndromes.
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Pretreatment Evaluation of Microcirculation by Dynamic Contrast-Enhanced Magnetic Resonance Imaging Predicts Survival in Primary Rectal Cancer Patients.
Int. J. Radiat. Oncol. Biol. Phys.
PUBLISHED: 02-25-2014
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To investigate the prognostic value of the perfusion index (PI), a microcirculatory parameter estimated from dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), which integrates information on both flow and permeability, to predict overall survival and disease-free survival in patients with primary rectal cancer.
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Comparison of real-time elastography and multiparametric MRI for prostate cancer detection: a whole-mount step-section analysis.
AJR Am J Roentgenol
PUBLISHED: 02-22-2014
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The purpose of this study was to compare prostate cancer detection rate of real-time elastography (RTE) with that of multiparametric MRI to evaluate the advantages and disadvantages of the two methods.
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Enhancement patterns in the fibro cellular tissue in different kinds of plaques of the internal carotid artery.
Eur J Radiol
PUBLISHED: 05-07-2013
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The differentiation between stable and vulnerable plaques in the internal carotid artery (ICA) remains a matter of interest. With the implementation of contrast agent in magnetic resonance imaging (MRI) a more detailed plaque characterization is possible. The study at hand focuses on enhancement patterns of fibro cellular tissue in different kinds of plaques in the ICA.
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Brain structure, number magnitude processing, and math proficiency in 6- to 7-year-old children born prematurely: a voxel-based morphometry study.
Neuroreport
PUBLISHED: 04-17-2013
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The aim of the present voxel-based morphometry study was to examine the link between brain structure and number skills in a group of 6-7-year-old children born prematurely, which are considered to be an at-risk population for mathematical learning disabilities. Therefore, gray and white matter density values were extracted from brain areas previously reported to be relevant for number processing in developing brain systems and, thereafter, correlated with response time results tapping semantic number knowledge [i.e. numerical distance effect (NDE) derived from a number comparison task] as well as with general math proficiency (as indexed by a standardized calculation test). Behavioral results disclosed a significant NDE, thus indicating well-established number magnitude representations for one-digit numerals in our study group. Significant positive correlations between gray matter and NDE emerged in parietal regions (including the right anterior inferior and the left superior parietal lobe) and in the right superior temporal gyrus. Moreover, white matter and NDE were negatively correlated in the right anterior inferior parietal lobe and the right inferior frontal gyrus. Overall, our results are novel insofar as they show that in 6-7-year-old children born prematurely, individual differences in gray and white matter structures are associated with numerical skills. Importantly, in our study group the observed link between brain structure and behavioral performance emerges only regarding an experimental task tapping semantic number knowledge, whereas general math proficiency does not seem to be related to individual differences in brain structure in our study group.
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Efficient MRI labeling of endothelial progenitor cells: Design of thiolated surface stabilized superparamagnetic iron oxide nanoparticles.
Eur J Pharm Biopharm
PUBLISHED: 02-13-2013
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The aim of this study was to design thiolated surface stabilized superparamagnetic iron oxide nanoparticles (TSS-SPIONs) for efficient internalization with high MRI sensitivity. TSS-SPIONs were developed by chelation between thiolated chitosan-thioglycolic acid (chitosan-TGA) hydrogel and iron ions (Fe(2+)/Fe(3+)). Likely, unmodified chitosan hydrogel SPIONs (UC-SPIONs) and uncoated SPIONs were used as control. Moreover, TSS-SPIONs were investigated regarding to their iron core size, hydrodynamic diameter, zeta potential, iron contents, molar relaxivities (r1 and r2), and cellular internalization. TSS-SPIONs demonstrated an iron oxide core diameter (crystallite size by XRD) of 3.1±0.02nm, a hydrodynamic diameter of 94±20nm, a zeta potential of +21±5mV, and an iron content of 3.6±0.9mg/mL. In addition, internalization of TSS-SPIONs into human endothelial progenitor cells (EPC) from umbilical cord blood was more than threefold and 17-fold higher in contrast to UC-SPIONs and SPIONs, respectively. With twofold lower incubation iron concentration of TSS-SPIONs, more than threefold higher internalization was achieved as compared to Resovist®. Also, cell viability of more than 90% was observed in the presence of TSS-SPIONs after 24h. The molar MR relaxivities (r2) value at 1.5T was threefold higher than that of Resovist® and demonstrated that TSS-SPIONs have the potential as very effective T2 contrast-enhancement agent. According to these findings, TSS-SPIONs with efficient internalization, lower cytotoxicity, and high MRI sensitivity seem to be promising for cell tracking.
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Evaluation of liver fat in the presence of iron with MRI using T2* correction: a clinical approach.
Eur Radiol
PUBLISHED: 01-19-2013
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To assess magnetic resonance imaging (MRI) with conventional chemical shift-based sequences with and without T2* correction for the evaluation of steatosis hepatitis (SH) in the presence of iron.
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White Matter Changes in Patients with Friedreich Ataxia after Treatment with Erythropoietin.
J Neuroimaging
PUBLISHED: 01-10-2013
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Erythropoietin (EPO) has received growing attention because of its neuroregenerative properties. Preclinical and clinical evidence supports its therapeutic potential in brain conditions like stroke, multiple sclerosis, and schizophrenia. Also, in Friedreich ataxia, clinical improvement after EPO therapy was shown. The aim of this study was to assess possible therapy-associated brain white matter changes in these patients.
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Tumor targeting and imaging with dual-peptide conjugated multifunctional liposomal nanoparticles.
Int J Nanomedicine
PUBLISHED: 01-01-2013
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The significant progress in nanotechnology provides a wide spectrum of nanosized material for various applications, including tumor targeting and molecular imaging. The aim of this study was to evaluate multifunctional liposomal nanoparticles for targeting approaches and detection of tumors using different imaging modalities. The concept of dual-targeting was tested in vitro and in vivo using liposomes derivatized with an arginine-glycine-aspartic acid (RGD) peptide binding to ?v?3 integrin receptors and a substance P peptide binding to neurokinin-1 receptors.
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Photoacoustic tomography of ex vivo mouse hearts with myocardial infarction.
J Biomed Opt
PUBLISHED: 04-05-2011
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In the present study, we evaluated the applicability of ex vivo photoacoustic imaging (PAI) on small animal organs. We used photoacoustic tomography (PAT) to visualize infarcted areas within murine hearts and compared these data to other imaging techniques [magnetic resonance imaging (MRI), micro-computed tomography] and histological slices. In order to induce ischemia, an in vivo ligation of the left anterior descending artery was performed on nine wild-type mice. After varying survival periods, the hearts were excised and fixed in formaldehyde. Samples were illuminated with nanosecond laser pulses delivered by a Nd:YAG pumped optical parametric oscillator. Ultrasound detection was achieved using a Mach-Zehnder interferometer (MZI) working as an integrating line detector. The voxel data were computed using a Fourier-domain based reconstruction algorithm, followed by inverse Radon transforms. The results clearly showed the capability of PAI to visualize myocardial infarction and to produce three-dimensional images with a spatial resolution of approximately 120 ?m. Regions of affected muscle tissue in PAI corresponded well with the results of MRI and histology. Photoacoustic tomography utilizing a MZI for ultrasound detection allows for imaging of small tissue samples. Due to its high spatial resolution, good soft tissue contrast and comparatively low cost, PAT offers great potentials for imaging.
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Cardiac imaging using clinical 1.5?t MRI scanners in a murine ischemia/reperfusion model.
J. Biomed. Biotechnol.
PUBLISHED: 07-13-2010
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To perform cardiac imaging in mice without having to invest in expensive dedicated equipment, we adapted a clinical 1.5 Tesla (T) magnetic resonance imaging (MRI) scanner for use in a murine ischemia/reperfusion model. Phase-sensitive inversion recovery (PSIR) sequence facilitated the determination of infarct sizes in vivo by late gadolinium enhancement. Results were compared to histological infarct areas in mice after ischemia/reperfusion procedure with a good correlation (r = 0.807, P < .001). In addition, fractional area change (FAC) was assessed with single slice cine MRI and was matched to infarct size (r = -0.837) and fractional shortening (FS) measured with echocardiography (r = 0.860); both P < .001. Here, we demonstrate the use of clinical 1.5 MRI scanners as a feasible method for basic phenotyping in mice. These widely available scanners are capable of investigating in vivo infarct dimensions as well as assessment of cardiac functional parameters in mice with reasonable throughput.
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Photoacoustic microtomography using optical interferometric detection.
J Biomed Opt
PUBLISHED: 05-13-2010
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A device for three-dimensional (3-D) photoacoustic tomography with resolution in the range of tens of micrometers is presented that uses a light beam for interferometric detection of acoustic waves. Reconstruction of the 3-D initial pressure distribution from the signals representing line integrals of the acoustic field is a two-step process. It uses an inversion of 2-D wave propagation to obtain line projections of the initial pressure distribution and the inverse Radon transform. The light beam, propagating freely in a water bath, is scanned either in an arc- or box-shaped curve around the object. Simulations are performed to compare the two scanning procedures. The projection images are obtained either using the filtered back projection algorithm for the pi-arc scanning mode or the frequency domain algorithm for the box scanning mode. While the former algorithm provides slightly better image quality, the latter is about 20 times faster. The ability of the photoacoustic tomography device to create 3-D images with constant resolution throughout the reconstruction volume is demonstrated experimentally using a human hair phantom. These measurements revealed a 3-D resolution below 100 mum. In a second experiment, 3-D imaging of an isolated mouse heart is demonstrated to show the applicability for preclinical and biological research.
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Phase-locked parallel movement of diaphragm and pelvic floor during breathing and coughing-a dynamic MRI investigation in healthy females.
Int Urogynecol J
PUBLISHED: 04-19-2010
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the aim of this pilot study was to demonstrate physiological movements of the muscular walls surrounding the abdominal cavity during breathing and coughing in healthy nulliparous women by means of real-time dynamic magnetic resonance imaging (MRI).
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Hepatic but not brain iron is rapidly chelated by deferasirox in aceruloplasminemia due to a novel gene mutation.
J. Hepatol.
PUBLISHED: 03-11-2010
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Aceruloplasminemia is a rare autosomal recessive neurodegenerative disease associated with brain and liver iron accumulation which typically presents with movement disorders, retinal degeneration, and diabetes mellitus. Ceruloplasmin is a multi-copper ferroxidase that is secreted into plasma and facilitates cellular iron export and iron binding to transferrin.
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Changes of renal blood flow after ESWL: assessment by ASL MR imaging, contrast enhanced MR imaging, and renal resistive index.
Eur J Radiol
PUBLISHED: 05-11-2009
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The annual incidence of stone formation is increased in the industrialised world. Extracorporeal shockwave lithotripsy is a non-invasive effective treatment of upper urinary tract stones. This study is aimed to evaluate changes of renal blood flow in patients undergoing extracorporeal shock wave lithotripsy (ESWL) by arterial spin labeling (ASL) MR imaging, contrast enhanced dynamic MR imaging, and renal resistive index (RI). Thirteen patients with nephrolithiasis were examined using MR imaging and Doppler ultrasound 12h before and 12h after ESWL. ASL sequence was done for both kidneys and followed by contrast enhanced MR imaging. In addition RI Doppler ultrasound measurements were performed. A significant increase in RI (p<0.001) was found in both treated and untreated kidneys. ASL MR imaging also showed significant changes in both kidneys (p<0.001). Contrast enhanced dynamic MR imaging did not show significant changes in the kidneys. ESWL causes changes in RI and ASL MR imaging, which seem to reflect changes in renal blood flow.
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Imaging of placental transport mechanisms: a review.
Eur. J. Obstet. Gynecol. Reprod. Biol.
PUBLISHED: 03-17-2009
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Functional analysis of material transfers requires precise statement of residence times in each tissue compartment. For the placenta, neither extractive biochemistry, isotope partitioning, nor mass-based quantitative assays provide adequate spatial resolution to allow the necessary precision. Dual-perfusion assays of material transfer in isolated placental cotyledons provide time-series data for two compartments, the maternal and fetal blood, but fail to distinguish the two cellular compartments (syncytiotrophoblast, fetal endothelium) which actively regulate rates of transfer in each direction for essentially every important molecule type. At present, no definitive technology exists for functional analysis of placental transfer functions. The challenge in developing such a technology lies in the exquisitely small and delicate structures involved, which are scaled at cellular and subcellular sizes (between 50 nm and 50 microm). The only available technologies attaining this high spatial resolution are imaging technologies, primarily light and electron microscopy. To achieve the high-quality images necessary, confocal laser scanning microscopy (CLSM) is required, to provide a uniform optical sectioning plane. In turn, this requires relatively high fluorescence intensities. Design of an adequate technology therefore bases on CLSM imaging fluorochrome-tagged tracers. The temporal resolution necessary to analyse placental material transfers is expected to be of the order of a few seconds, so that conventional wet-fixation protocols are too slow. For adequately rapid fixation, snap-freezing is required. As part of this review we report results obtained from an appropriately designed experimental protocol, analysed by CLSM and transmission electron microscopy (TEM). The images acquired were tested for uniformity of illumination and fluorescence emission strength. Relevant data was encoded in the green channel of the trichrome images obtained, and this was thresholded by application of strict quantitative criteria. The thresholding procedure is suitable for automation and produces reproducible, objectifiable results. Thresholded images were subjected to image calculation procedures designed to highlight image elements (pixels) containing (green) fluorescence associated with the tracer protein; all other sources of fluorescence were visualised in the final images only if no green fluorescence was detectable in that pixel. The resulting images were maps, showing the distribution of tracer molecules at a predefined time interval after perfusion of the tracer into the vital (term) cotyledon. Spatial resolution was routinely better than 1 microm and temporal resolution was approximately 5s. At timepoints up to 10 min after intravital application into the fetal vascular circulation, tracer was associated with capillaries in the villous structures, and no tracer was observed in the syncytiotrophoblast. Clear distinction was achieved between the four tissue compartments relevant to placental transfers, thus providing a novel technology capable of generating high-quality data concerning the regulation of transfers of any molecule that can bear a fluorescent tag. The potential applications of this methodology lie in analyses of factors influencing the rates of fetomaternal and maternofetal exchanges (for example, drugs), and of functional responses of the placental regulation to pathophysiological conditions such as hypoxia.
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Developmental dyscalculia: compensatory mechanisms in left intraparietal regions in response to nonsymbolic magnitudes.
Behav Brain Funct
PUBLISHED: 02-06-2009
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Functional magnetic resonance imaging (fMRI) studies investigating the neural mechanisms underlying developmental dyscalculia are scarce and results are thus far inconclusive. Main aim of the present study is to investigate the neural correlates of nonsymbolic number magnitude processing in children with and without dyscalculia.
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Proof of concept: differential effects of Valsalva and straining maneuvers on the pelvic floor.
Eur. J. Obstet. Gynecol. Reprod. Biol.
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To prove a basic physiological principle in healthy women, demonstrating different movement patterns of diaphragm, pelvic floor, and muscular wall surrounding the abdominal cavity during a Valsalva maneuver as opposed to a straining maneuver, by means of real-time dynamic magnetic resonance imaging (MRI).
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Multipolar radiofrequency ablation using 4-6 applicators simultaneously: a study in the ex vivo bovine liver.
Eur J Radiol
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In this study the volume and shape of coagulation zones after multipolar radiofrequency ablation (RFA) with simultaneous use of 4-6 applicators in the ex vivo bovine liver were investigated. The RF-applicators were positioned in 13 different configurations to simulate ablation of large solitary tumors and simultaneous ablation of multiple lesions with 120 kJ of applied energy/session. In total, 110 coagulation zones were induced. Standardized measurements of the volume and shape of the coagulation zones were carried out on magnetic resonance images and statistically analyzed. The coagulation zones induced with solitary applicators and with 2 applicators were imperceptibly small and incomplete, respectively. At 20mm applicator distance, the total ablated volume was significantly larger if all applicators were arranged in a single group compared to placement in 2 distant applicator groups, each consisting of 3 applicators (p=.001). The mean total coagulated volume ranged from immeasurably small (if 6 solitary applicators were applied simultaneously) to 74.7 cc (if 6 applicators at 30 mm distance between neighboring applicators were combined to a single group). Applicator distance, number and positioning array impacted time and shape. The coagulation zones surrounding groups with 4-6 applicators were regularly shaped, homogeneous and completely fused, and the axial diameters were almost constant. In conclusion, multipolar RFA with 4-6 applicators is feasible. The multipolar simultaneous mode should be applied for large and solitary lesions only, small and multiple tumors should be ablated consecutively in standard multipolar mode with up to 3 applicators.
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What is Visualize?

JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

How does it work?

We use abstracts found on PubMed and match them to JoVE videos to create a list of 10 to 30 related methods videos.

Video X seems to be unrelated to Abstract Y...

In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.