To provide high-resolution cardiac T
mapping of various cardiac phases and cine imaging within a single breath-hold using continuous golden ratio-based radial acquisition and model-based iterative ...image reconstruction.
Data acquisition was performed continuously using golden ratio-based radial sampling and multiple inversion pulses were applied independent of the heart rate. Native T
maps of diastole and systole were reconstructed with in-plane resolution of 1.3 × 1.3 mm
using model-based iterative image reconstruction. Cine images with 30 cardiac phases were reconstructed from the same data using kt-SENSE. The method was evaluated in a commercially available T
phantom and 10 healthy subjects. In vivo T
assessment was carried out segment-wise.
Evaluation in the phantom demonstrated accurate T
times (R
> 0.99) and insensitivity to the heart rate. In vivo T
values did not differ between systole and diastole, and T
times assessed by the proposed approach were longer than measured with a modified Look-Locker inversion recovery (MOLLI) sequence, except for lateral segments. Cine images had a consistent dark-blood contrast and functional assessment was in agreement with assessment based on Cartesian cine scans (difference in ejection fraction: 0.26 ± 2.65%, P = 0.65).
The proposed approach provides native T
maps of diastole and systole with high spatial resolution and cine images simultaneously within 16 s, which could strongly improve the scan efficiency.
To improve the efficiency of native and postcontrast high-resolution cardiac T
mapping by utilizing cardiac motion correction.
Common cardiac T
mapping techniques only acquire data in a small part of ...the cardiac cycle, leading to inefficient data sampling. Here, we present an approach in which 80% of each cardiac cycle is used for T
mapping by integration of cardiac motion correction. Golden angle radial data was acquired continuously for 8 s with in-plane resolution of 1.3 × 1.3 mm
. Cine images were reconstructed for nonrigid cardiac motion estimation. Images at different TIs were reconstructed from the same data, and motion correction was performed prior to T
mapping. Native T
mapping was evaluated in healthy subjects. Furthermore, the technique was applied for postcontrast T
mapping in 5 patients with suspected fibrosis.
Cine images with high contrast were obtained, leading to robust cardiac motion estimation. Motion-corrected T
maps showed myocardial T
times similar to cardiac-triggered T
maps obtained from the same data (1288 ± 49 ms and 1259 ± 55 ms, respectively) but with a 34% improved precision (spatial variation: 57.0 ± 12.5 ms and 94.8 ± 15.4 ms, respectively, P < 0.0001) due to the increased amount of data. In postcontrast T
maps, focal fibrosis could be confirmed with late contrast-enhancement images.
The proposed approach provides high-resolution T
maps within 8 s. Data acquisition efficiency for T
mapping was improved by a factor of 5 by integration of cardiac motion correction, resulting in precise T
maps.
There is an emerging concept in clinical nephrology that acute kidney injury (AKI) can initiate chronic kidney disease (CKD). However, potential mechanisms by which this may occur remain elusive. ...Hence, this study tested the hypotheses that 1) AKI triggers progressive activation of selected proinflammatory genes, 2) there is a relative failure of compensatory anti-inflammatory gene expression, 3) proinflammatory lipid accumulation occurs, 4) these changes correspond with "gene-activating" histone acetylation, and 5) in concert, progressive renal disease results. CD-1 mice were subjected to 30 min of unilateral renal ischemia. Assessments were made 1 day, 1 wk, or 3 wk later. Results were contrasted to those observed in uninjured contralateral kidneys or in kidneys from normal mice. Progressive renal injury occurred throughout the 3-wk postischemic period, as denoted by stepwise increases in neutrophil gelatinase-associated lipocalin gene induction and ongoing histologic damage. By 3 wk postischemia, progressive renal disease was observed (massive tubular dropout; 2/3rds reduction in renal weight). These changes corresponded with progressive increases in proinflammatory cytokine/chemokine gene expression (MCP-1, TNF-α, TGF-β1), a relative failure of anti-inflammatory enzyme/cytokine (heme oxygenase-1; IL-10) upregulation, and progressive renal lipid (cholesterol/triglyceride) loading. Stepwise increases in collagen III mRNA and collagen deposition (Sirius red staining) indicated a progressive profibrotic response. Postischemic dexamethasone treatment significantly preserved renal mass, indicating functional significance of the observed proinflammatory state. Progressive gene-activating H3 acetylation was observed by ELISA, rising from 5% at baseline to 75% at 3 wk. This was confirmed by chromatin immunoprecipitation assay of target genes. In sum, these results provide experimental support for the clinical concept that AKI can trigger CKD, this is partially mediated by progressive postischemic inflammation, ongoing lipid accumulation results (potentially evoking "lipotoxicity"), and increasing histone acetylation at proinflammatory/profibrotic genes may contribute to this self-sustaining injury-promoting state.
Renal Cortical Pyruvate Depletion during AKI ZAGER, Richard A; JOHNSON, Ali C. M; BECKER, Kirsten
Journal of the American Society of Nephrology,
05/2014, Letnik:
25, Številka:
5
Journal Article
Abstract Purpose To evaluate the momentary association between exposure to alcohol advertising and middle-school students' beliefs about alcohol in real-world settings and to explore racial/ethnic ...differences in this association. Methods Middle-school students (N = 588) carried handheld data collection devices for 14 days, recording their exposures to all forms of alcohol advertising during the assessment period. Students also responded to three investigator-initiated control prompts (programmed to occur randomly) on each day of the assessment period. After each exposure to advertising and at each control prompt, students reported their beliefs about alcohol. Mixed-effects regression models compared students' beliefs about alcohol between moments of exposure to alcohol advertising and control prompts. Results Students perceived the typical person their age who drinks alcohol (prototype perceptions) more favorably and perceived alcohol use as more normative at times of exposure to alcohol advertising than at times of nonexposure (i.e., at control prompts). Exposure to alcohol advertising was not associated with shifts in the perceived norms of black and Hispanic students, however, and the association between exposure and prototype perceptions was stronger among non-Hispanic students than among Hispanic students. Conclusions Exposure to alcohol advertising is associated with acute shifts in adolescents' perceptions of the typical person that drinks alcohol and the normativeness of drinking. These associations are both statistically and substantively meaningful.
Purpose
To provide high‐resolution cardiac T1 mapping of various cardiac phases and cine imaging within a single breath‐hold using continuous golden ratio‐based radial acquisition and model‐based ...iterative image reconstruction.
Methods
Data acquisition was performed continuously using golden ratio‐based radial sampling and multiple inversion pulses were applied independent of the heart rate. Native T1 maps of diastole and systole were reconstructed with in‐plane resolution of 1.3 × 1.3 mm2 using model‐based iterative image reconstruction. Cine images with 30 cardiac phases were reconstructed from the same data using kt‐SENSE. The method was evaluated in a commercially available T1 phantom and 10 healthy subjects. In vivo T1 assessment was carried out segment‐wise.
Results
Evaluation in the phantom demonstrated accurate T1 times (R2 > 0.99) and insensitivity to the heart rate. In vivo T1 values did not differ between systole and diastole, and T1 times assessed by the proposed approach were longer than measured with a modified Look‐Locker inversion recovery (MOLLI) sequence, except for lateral segments. Cine images had a consistent dark‐blood contrast and functional assessment was in agreement with assessment based on Cartesian cine scans (difference in ejection fraction: 0.26 ± 2.65%, P = 0.65).
Conclusion
The proposed approach provides native T1 maps of diastole and systole with high spatial resolution and cine images simultaneously within 16 s, which could strongly improve the scan efficiency.
Purpose
To improve the efficiency of native and postcontrast high‐resolution cardiac T1 mapping by utilizing cardiac motion correction.
Methods
Common cardiac T1 mapping techniques only acquire data ...in a small part of the cardiac cycle, leading to inefficient data sampling. Here, we present an approach in which 80% of each cardiac cycle is used for T1 mapping by integration of cardiac motion correction. Golden angle radial data was acquired continuously for 8 s with in‐plane resolution of 1.3 × 1.3 mm2. Cine images were reconstructed for nonrigid cardiac motion estimation. Images at different TIs were reconstructed from the same data, and motion correction was performed prior to T1 mapping. Native T1 mapping was evaluated in healthy subjects. Furthermore, the technique was applied for postcontrast T1 mapping in 5 patients with suspected fibrosis.
Results
Cine images with high contrast were obtained, leading to robust cardiac motion estimation. Motion‐corrected T1 maps showed myocardial T1 times similar to cardiac‐triggered T1 maps obtained from the same data (1288 ± 49 ms and 1259 ± 55 ms, respectively) but with a 34% improved precision (spatial variation: 57.0 ± 12.5 ms and 94.8 ± 15.4 ms, respectively, P < 0.0001) due to the increased amount of data. In postcontrast T1 maps, focal fibrosis could be confirmed with late contrast‐enhancement images.
Conclusion
The proposed approach provides high‐resolution T1 maps within 8 s. Data acquisition efficiency for T1 mapping was improved by a factor of 5 by integration of cardiac motion correction, resulting in precise T1 maps.
Studies of experimental acute kidney injury (AKI) are critically dependent on having precise methods for assessing the extent of tubular cell death. However, the most widely used techniques either ...provide indirect assessments (e.g., BUN, creatinine), suffer from the need for semi-quantitative grading (renal histology), or reflect the status of residual viable, not the number of lost, renal tubular cells (e.g., NGAL content). Lactate dehydrogenase (LDH) release is a highly reliable test for assessing degrees of in vitro cell death. However, its utility as an in vivo AKI marker has not been defined. Towards this end, CD-1 mice were subjected to graded renal ischemia (0, 15, 22, 30, 40, or 60 min) or to nephrotoxic (glycerol; maleate) AKI. Sham operated mice, or mice with AKI in the absence of acute tubular necrosis (ureteral obstruction; endotoxemia), served as negative controls. Renal cortical LDH or NGAL levels were assayed 2 or 24 hrs later. Ischemic, glycerol, and maleate-induced AKI were each associated with striking, steep, inverse correlations (r, -0.89) between renal injury severity and renal LDH content. With severe AKI, >65% LDH declines were observed. Corresponding prompt plasma and urinary LDH increases were observed. These observations, coupled with the maintenance of normal cortical LDH mRNA levels, indicated the renal LDH efflux, not decreased LDH synthesis, caused the falling cortical LDH levels. Renal LDH content was well maintained with sham surgery, ureteral obstruction or endotoxemic AKI. In contrast to LDH, renal cortical NGAL levels did not correlate with AKI severity. In sum, the above results indicate that renal cortical LDH assay is a highly accurate quantitative technique for gauging the extent of experimental acute ischemic and toxic renal injury. That it avoids the limitations of more traditional AKI markers implies great potential utility in experimental studies that require precise quantitation of tubule cell death.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The purpose of this study was to quantify middle school youth's exposure to alcohol advertisements across media and venues, determine venues of greatest exposure, and identify characteristics of ...youth who are most exposed.
Over a 10-month period in 2013, 589 Los Angeles-area youth ages 11-14 from diverse racial/ethnic backgrounds completed a short paper-and-pencil survey assessing background characteristics and then participated in a 14-day ecological momentary assessment, logging all exposures to alcohol advertisements on handheld computers as they occurred.
African American and Hispanic youth were exposed to an average of 4.1 and 3.4 advertisements per day, respectively, nearly two times as many as non-Hispanic White youth, who were exposed to 2.0 advertisements per day. Girls were exposed to 30% more advertisements than boys. Most exposures were to outdoor advertisements, with television advertisements a close second.
Exposure to alcohol advertising is frequent among middle school-age youth and may put them at risk for earlier or more frequent underage drinking. Greater restrictions on alcohol advertising outdoors and on television should be considered by regulators and by the alcohol industry and should focus particularly on reducing exposure among minority youth.
National travel distances for emergency care Tolpadi, Anagha; Elliott, Marc N; Waxman, Daniel ...
BMC health services research,
03/2022, Letnik:
22, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Most emergency department (ED) patients arrive by their own transport and, for various reasons, may not choose the nearest ED. How far patients travel for ED treatment may reflect both patients' ...access to care and severity of illness. In this study, we aimed to examine the travel distance and travel time between a patient's home and ED they visited and investigate how these distances/times vary by patient and hospital characteristics.
We randomly sampled and collected data from 14,812 patients discharged to the community (DTC) between January and March 2016 from 50 hospital-based EDs nationwide. We geocoded and calculated the distance and travel time between patient and hospital-based ED addresses, examined the travel distances/ times between patients' home and the ED they visited, and used mixed-effects regression models to investigate how these distances/times vary by patient and hospital characteristics.
Patients travelled an average of 8.0 (SD = 10.9) miles and 17.3 (SD = 18.0) driving minutes to the ED. Patients travelled significantly farther to avoid EDs in lower performing hospitals (p < 0.01) and in the West (p < 0.05) and Midwest (p < 0.05). Patients travelled farther when visiting EDs in rural areas. Younger patients travelled farther than older patients.
Understanding how far patients are willing to travel is indicative of whether patient populations have adequate access to ED services. By showing that patients travel farther to avoid a low-performing hospital, we provide evidence that DTC patients likely do exercise some choice among EDs, indicating some market incentives for higher-quality care, even for some ED admissions. Understanding these issues will help policymakers better define access to ED care and assist in directing quality improvement efforts. To our knowledge, our study is the most comprehensive nationwide characterization of patient travel for ED treatment to date.
Celotno besedilo
Dostopno za:
CEKLJ, DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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