72 research outputs found
Quantitative evaluation of aortic valve regurgitation in 4D flow cardiac magnetic resonance: at which level should we measure?
PURPOSE
To find the best level to measure aortic flow for quantification of aortic regurgitation (AR) in 4D flow CMR.
METHODS
In 27 congenital heart disease patients with AR (67% male, 31 ± 16 years) two blinded observers measured antegrade, retrograde, net aortic flow volumes and regurgitant fractions at 6 levels in 4D flow: (1) below the aortic valve (AV), (2) at the AV, (3) at the aortic sinus, (4) at the sinotubular junction, (5) at the level of the pulmonary arteries (PA) and (6) below the brachiocephalic trunk. 2D phase contrast (2DPC) sequences were acquired at the level of PA. All patients received prior transthoracic echocardiography (TTE) with AR severity grading according to a recommended multiparametric approach.
RESULTS
After assigning 2DPC measurements into AR grading, agreement between TTE AR grading and 2DPC was good (κ = 0.88). In 4D flow, antegrade flow was similar between the six levels (p = 0.87). Net flow was higher at level 1-2 than at levels 3-6 (p < 0.05). Retrograde flow and regurgitant fraction at level 1-2 were lower compared to levels 3-6 (p < 0.05). Reproducibility (inter-reader agreement: ICC 0.993, 95% CI 0.986-0.99; intra-reader agreement: ICC 0.982, 95%CI 0.943-0.994) as well as measurement agreement between 4D flow and 2DPC (ICC 0.994; 95%CI 0.989 - 0.998) was best at the level of PA.
CONCLUSION
For estimating severity of AR in 4D flow, best reproducibility along with best agreement with 2DPC measurements can be expected at the level of PA. Measurements at AV or below AV might underestimate AR
Feasibility of non-gated dynamic fetal cardiac MRI for identification of fetal cardiovascular anatomy
INTRODUCTION
To evaluate the feasibility of identifying the fetal cardiac and thoracic vascular structures with non-gated dynamic balanced steady-state free precession (SSFP) MRI sequences.
METHODS
We retrospectively assessed the visibility of cardiovascular anatomy in 60 fetuses without suspicion of congenital heart defect. Non-gated dynamic balanced SSFP sequences were acquired in three anatomic planes of the fetal thorax. The images were analyzed following a segmental approach in consensus reading by an experienced pediatric cardiologist and radiologist. An imaging score was defined by giving one point to each visualized structure, yielding a maximum score of 21 points. Image quality was rated from 0 (poor) to 2 (excellent). The influence of gestational age (GA), field strength, placenta position, and maternal panniculus on image quality and imaging score were tested.
RESULTS
30 scans were performed at 1.5T, 30 at 3T. Heart position, atria and ventricles could be seen in all 60 fetuses. Basic diagnosis (>12 points) was achieved in 54 cases. The mean imaging score was 16.8+/-3.8. Maternal panniculus (r=-0.3; p=0.015) and gestational age (r=0.6; p<0.001) correlated with imaging score. Field strength influenced image quality, with 1.5T being better than 3T images (p=0.012). Imaging score or quality were independent of placenta position.
DISCUSSION/CONCLUSION
Fetal cardiac MRI with non-gated SSFP sequences enables recognition of basic cardiovascular anatomy
The personal is political: reframing individual acts of kindness as social solidarity in social work practice
This paper develops the theoretical position proposed by Zygmunt Bauman (2009), that one of the greatest contemporary ‘social evils’ or injustices we face in society, is the total marketization and individualisation of our lived experience. Bauman (2009) along with Harvey (2005) argues that the last forty years of social, political, and economic reform under the zeitgeist of neoliberalism have transferred the burden of care from the state to the individual. This paper will explore the position that the dominant neoliberal culture within social work, in the form of ‘new managerialism’ has reconstituted social work institutionally as one where interventions now focus on minimum statutory interventions emphasising; risk management, resource allocation, audit culture, and the promotion of self-care through a case work methodology. The discussion will analyse these macro social, political and economic discourses using an ethnographic approach based upon Michael Burawoy’s Global Ethnographic (GE) methodology (Burawoy et al, 2010). Despite the current landscape the research highlights the importance of the personal reframed as the political, and the nuanced ways in which acts of defiance and resistance against the prevailing orthodoxies have been adopted by social workers on the front line
Longevity as an Animal Welfare Issue Applied to the Case of Foot Disorders in Dairy Cattle
As síndromes e crises epilépticas e suas relações com trabalho: estudo prospectivo ambulatorial de 412 pacientes
Contrasting estuarine processing of dissolved organic matter derived from natural and human‐impacted landscapes
The flux of terrigenous organic carbon through estuaries is an important and changing, yet poorly understood, component of the global carbon cycle. Using dissolved organic carbon (DOC) and fluorescence data from thirteen British estuaries draining catchments with highly variable land uses, we show that land use strongly influences the fate of DOC across the land-ocean transition via its influence on the composition and lability of the constituent dissolved organic matter (DOM). In estuaries draining peatland-dominated catchments, DOC was highly correlated with biologically refractory “humic-like” terrigenous material which tended to be conservatively transported along the salinity gradient. In contrast, there was a weaker correlation between DOC and DOM components within estuaries draining catchments with a high degree of human impact, i.e. relatively larger percentage of arable and (sub-)urban land uses. These arable and (sub-)urban estuaries contain a high fraction of bioavailable “protein-like” material that behaved non-conservatively, with both DOC removals and additions occurring. In general, estuaries draining catchments with a high percentage of peatland (≥18 %) have higher area-specific estuarine exports of DOC (>13 g C m-2 yr-1) compared to those estuaries draining catchments with a high percentage (≥46 %) of arable and (sub-)urban land uses (<2.1 g C m-2 yr-1). Our data indicate that these arable and (sub-)urban estuaries tend to export, on average, ∼50 % more DOC to coastal areas than they receive from rivers, due to net anthropogenic derived organic matter inputs within the estuary
Sources, Composition, and Export of Particulate Organic Matter Across British Estuaries
Estuaries receive and process a large amount of particulate organic carbon (POC) prior to its export into coastal waters. Studying the origin of this POC is key to understanding the fate of POC and the role of estuaries
in the global carbon cycle. Here, we evaluated the concentrations of POC, as well as particulate organic nitrogen (PON), and used stable carbon and nitrogen isotopes to assess their sources across 13 contrasting British estuaries during five different sampling campaigns over 1 year. We found a high variability in POC and PON
concentrations across the salinity gradient, reflecting inputs, and losses of organic material within the estuaries. Catchment land cover appeared to influence the contribution of POC to the total organic carbon flux from the estuary to coastal waters, with POC contributions >36% in estuaries draining catchments with a high percentage of urban/suburban
land, and <11% in estuaries draining catchments with a high peatland cover. There was no seasonal pattern in the
isotopic composition of POC and PON, suggesting similar sources for each estuary over time. Carbon isotopic
ratios were depleted (−26.7 ± 0.42‰, average ± sd) at the lowest salinity waters, indicating mainly terrigenous
POC (TPOC). Applying a two-source mixing model, we observed high variability in the contribution of TPOC at the highest salinity waters between estuaries, with a median value of 57%. Our results indicate a large transport of terrigenous organic carbon into coastal waters, where it may be buried, remineralized, or transported offshore
Sources, composition, and export of particulate organic matter across British estuaries
Estuaries receive and process a large amount of particulate organic carbon (POC) prior to its export into coastal waters. Studying the origin of this POC is key to understanding the fate of POC and the role of estuaries in the global carbon cycle. Here, we evaluated the concentrations of POC, as well as particulate organic nitrogen (PON), and used stable carbon and nitrogen isotopes to assess their sources across 13 contrasting British estuaries during five different sampling campaigns over 1 year. We found a high variability in POC and PON concentrations across the salinity gradient, reflecting inputs, and losses of organic material within the estuaries. Catchment land cover appeared to influence the contribution of POC to the total organic carbon flux from the estuary to coastal waters, with POC contributions >36% in estuaries draining catchments with a high percentage of urban/suburban land, and <11% in estuaries draining catchments with a high peatland cover. There was no seasonal pattern in the isotopic composition of POC and PON, suggesting similar sources for each estuary over time. Carbon isotopic ratios were depleted (−26.7 ± 0.42‰, average ± sd) at the lowest salinity waters, indicating mainly terrigenous POC (TPOC). Applying a two-source mixing model, we observed high variability in the contribution of TPOC at the highest salinity waters between estuaries, with a median value of 57%. Our results indicate a large transport of terrigenous organic carbon into coastal waters, where it may be buried, remineralized, or transported offshore
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