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Background: The immediate impact of catheter ablation on left atrial mechanical function and the timeline for its recovery in patients undergoing ablation for atrial fibrillation (AF) remain uncertain. The mechanical function response to catheter ablation in patients with different AF types is poorly understood. Methods: A total of 113 AF patients were included in this retrospective study. Each patient had three magnetic resonance imaging (MRI) studies in sinus rhythm: one pre-ablation, one immediate post-ablation (within 2 days after ablation), and one post-ablation follow-up MRI (≤ 3 months). We used feature tracking in the MRI cine images to determine peak longitudinal atrial strain (PLAS). We evaluated the change in strain from pre-ablation, immediately after ablation to post-ablation follow-up in a short-term study (< 50 days) and a 3-month study (3 months after ablation). Results: The PLAS exhibited a notable reduction immediately after ablation, compared to both pre-ablation levels and those observed in follow-up studies conducted at short-term (11.1 ± 9.0 days) and 3-month (69.6 ± 39.6 days) intervals. However, there was no difference between follow-up and pre-ablation PLAS. The PLAS returned to 95% pre-ablation level within 10 days. Paroxysmal AF patients had significantly higher pre-ablation PLAS than persistent AF patients in pre-ablation MRIs. Both type AF patients had significantly lower immediate post-ablation PLAS compared with pre-ablation and post-ablation PLAS. Conclusion: The present study suggested a significant drop in PLAS immediately after ablation. Left atrial mechanical function recovered within 10 days after ablation. The drop in PLAS did not show a substantial difference between paroxysmal and persistent AF patients. [ABSTRACT FROM AUTHOR]

This Article surveys cases from the United States Court of Appeals for the Eleventh Circuit from January 1, 2023, through December 31, 2023, in which immigration law was a central focus of the case.1 During this time, the Eleventh Circuit decided several of these cases. As such, the cases discussed herein are those that explore jurisdictional boundaries of the Eleventh Circuit's appellate review of immigration cases, and those that interpret standards that impact an immigrant's ability to obtain relief. This Article discusses (1) removal cancellation, including the court's jurisdiction to review such decisions, the standard for removal cancellation, and the constitutionality of denying such applications; and (2) other important immigration issues, including asylum petitions and the ability of state governments to impact federal immigration policy. Finally, it concludes with recent developments in immigration law. [ABSTRACT FROM AUTHOR]

The article discusses the comparative size of sets A and B, focusing on three main questions regarding their relative sizes based on injections and surjections. Topics include the injective account versus the surjective account of set size, the implications of the axiom of choice on these accounts, and the challenges to Cantor's definitions of cardinality.

Background: The arterial input function (AIF) is vital for myocardial blood flow quantification in cardiac MRI to indicate the input time–concentration curve of a contrast agent. Inaccurate AIFs can significantly affect perfusion quantification. Purpose: When only saturated and biased AIFs are measured, this work investigates multiple ways of leveraging tissue curve information, including using AIF + tissue curves as inputs and optimizing the loss function for deep neural network training. Methods: Simulated data were generated using a 12-parameter AIF mathematical model for the AIF. Tissue curves were created from true AIFs combined with compartment-model parameters from a random distribution. Using Bloch simulations, a dictionary was constructed for a saturation-recovery 3D radial stack-of-stars sequence, accounting for deviations such as flip angle, T2* effects, and residual longitudinal magnetization after the saturation. A preliminary simulation study established the optimal tissue curve number using a bidirectional long short-term memory (Bi-LSTM) network with just AIF loss. Further optimization of the loss function involves comparing just AIF loss, AIF with compartment-model-based parameter loss, and AIF with compartment-model tissue loss. The optimized network was examined with both simulation and hybrid data, which included in vivo 3D stack-of-star datasets for testing. The AIF peak value accuracy and k t r a n s results were assessed. Results: Increasing the number of tissue curves can be beneficial when added tissue curves can provide extra information. Using just the AIF loss outperforms the other two proposed losses, including adding either a compartment-model-based tissue loss or a compartment-model parameter loss to the AIF loss. With the simulated data, the Bi-LSTM network reduced the AIF peak error from −23.6 ± 24.4% of the AIF using the dictionary method to 0.2 ± 7.2% (AIF input only) and 0.3 ± 2.5% (AIF + ten tissue curve inputs) of the network AIF. The corresponding k t r a n s error was reduced from −13.5 ± 8.8% to −0.6 ± 6.6% and 0.3 ± 2.1%. With the hybrid data (simulated data for training; in vivo data for testing), the AIF peak error was 15.0 ± 5.3% and the corresponding k t r a n s error was 20.7 ± 11.6% for the AIF using the dictionary method. The hybrid data revealed that using the AIF + tissue inputs reduced errors, with peak error (1.3 ± 11.1%) and k t r a n s error (−2.4 ± 6.7%). Conclusions: Integrating tissue curves with AIF curves into network inputs improves the precision of AI-driven AIF corrections. This result was seen both with simulated data and with applying the network trained only on simulated data to a limited in vivo test dataset. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study is to design a method of myocardial T1 quantification in small laboratory animals and to investigate the effects of spatiotemporal regularization and the needed acquisition duration. Methods: We propose a compressed‐sensing approach to T1 quantification based on self‐gated inversion‐recovery radial two/three‐dimensional (2D/3D) golden‐angle stack‐of‐stars acquisition with image reconstruction performed using total‐variation spatiotemporal regularization. The method was tested on a phantom and on a healthy rat, as well as on rats in a small myocardium‐remodeling study. Results: The results showed a good match of the T1 estimates with the results obtained using the ground‐truth method on a phantom and with the literature values for rats myocardium. The proposed 2D and 3D methods showed significant differences between normal and remodeling myocardium groups for acquisition lengths down to approximately 5 and 15 min, respectively. Conclusions: A new 2D and 3D method for quantification of myocardial T1 in rats was proposed. We have shown the capability of both techniques to distinguish between normal and remodeling myocardial tissue. We have shown the effects of image‐reconstruction regularization weights and acquisition length on the T1 estimates. [ABSTRACT FROM AUTHOR]

Background: The use of a gradient echo spin echo (GESE) method to obtain rapid T2 and T2* estimation in the heart has been proposed. The effect of acquisition parameter settings on T2 and T2* bias and precision have not been investigated in depth. Purpose: To understand factors impacting the quantification of T2 and T2* values with a gradient echo spin echo (GESE) method using echo planar imaging (EPI) readouts in a reduced field of view acquisition. Methods: The GESE method is implemented with a reduced field‐of‐view using an outer volume suppression (OVS) technique to minimize the time for multi‐echo EPI readouts. The number of EPI readouts (images) for the GESE is optimized using Cramer‐Rao Lower Bound (CRLB) and Monte Carlo simulations with a nonlinear least‐square (NLLS) estimator. The SNR requirements were studied using the latter simulation method for a selected range of T2 and T2* values and T2/T2* ratios. Two healthy control subjects were imaged with the proposed GESE sequence and evaluated with the NLLS estimation method. In addition, the proposed OVS method was compared with a saturation bands OVS method in one subject. Clinical T2 and T2* mappings were used as the reference. Results: The optimal number of EPI readouts is five and the performance is slightly better when the refocusing pulse is placed between the 2nd and 3rd readouts. The SNR requirement for achieving a target bias < 1 ms and standard deviation (SD) < 5 ms is more demanding when T2/T2* ratio increases. The minimum SNR requirement in the GESE acquisition should vary from 6 to 20 depending on specific myocardial T2 and T2* values at 3T. The T2 and T2* estimates using the proposed OVS method and the saturation bands OVS method are both similar to the reference. Conclusion: The GESE sequence with five EPI readouts is a feasible and efficient technique that can estimate T2 and T2* values in the septal myocardium within a heartbeat when the SNR requirement can be satisfied. [ABSTRACT FROM AUTHOR]

A dog was referred for investigation into polyuria and polydipsia. Investigations showed a right adrenal mass, adrenalectomy was performed, and histopathology reported a carcinoma with local invasion. Carboplatin was selected as an adjuvant chemotherapy. Initially, did not show signs of recurrence, but 9 months later the clinical signs recurred, and staging was consistent with recurrence of the carcinoma with local hepatic invasion. The mitotane ablative protocol was chosen. Our patient developed mineralocorticoid deficiency 60 days later, but never developed clinical signs of cortisol deficiency as it was started on prednisolone. Kintzer and Peterson reported that dogs with metastatic disease experienced poorer response to mitotane and shorter survival time. However, our patient responded very well, with no side effect and remission of all clinical signs. The patient is alive at time of writing this report, 10 months after starting mitotane and 22 months after diagnosis. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the agreement of 4D flow cMRI-derived bulk flow features and fluid (blood) velocities in the carotid bifurcation using prospective and retrospective gating techniques. Methods: Prospective and retrospective ECG-gated three-dimensional (3D) cine phase-contrast cardiac MRI with three-direction velocity encoding (i.e., 4D flow cMRI) data were acquired in ten carotid bifurcations from men (n = 3) and women (n = 2) that were cardiovascular disease-free. MRI sequence parameters were held constant across all scans except temporal resolution values differed. Velocity data were extracted from the fluid domain and evaluated across the entire volume or at defined anatomic planes (common, internal, external carotid arteries). Qualitative agreement between gating techniques was performed by visualizing flow streamlines and topographical images, and statistical comparisons between gating techniques were performed across the fluid volume and defined anatomic regions. Results: Agreement in the kinematic data (e.g., bulk flow features and velocity data) were observed in the prospectively and retrospectively gated acquisitions. Voxel differences in time-averaged, peak systolic, and diastolic-averaged velocity magnitudes between gating techniques across all volunteers were 2.7%, 1.2%, and 6.4%, respectively. No significant differences in velocity magnitudes or components ( v r , v θ , v z ) were observed. Importantly, retrospective acquisitions captured increased retrograde flow in the internal carotid artery (i.e., carotid sinus) compared to prospective acquisitions (10.4 ± 6.3% vs. 4.6 ± 5.3%; p < 0.05). Conclusion: Prospective and retrospective ECG-gated 4D flow cMRI acquisitions provide comparable evaluations of fluid velocities, including velocity vector components, in the carotid bifurcation. However, the increased temporal coverage of retrospective acquisitions depicts increased retrograde flow patterns (i.e., disturbed flow) not captured by the prospective gating technique. [ABSTRACT FROM AUTHOR]

Small‐ and medium‐sized enterprises (SMEs) can have significant resources, capacities, and influence in their communities, suggesting they have the potential to be agents for transformative sustainability. However, SMEs will need to move beyond firm‐centered sustainable business practices towards strategic approaches that encompass and contribute to resilience‐building processes. Amid the unfolding COVID‐19 pandemic, we explored what types of sustainable business practices of SMEs can contribute to individual, organizational, and community resilience. We identified six clusters of practice that are important in this regard. The clusters are not solely technical or "environmental" but rather illustrative of deeper sustainable values shaped by organizational structure, culture, and behavior. This paper suggests that SMEs can pursue transformative approaches to sustainability that are more environmentally, socially, and economically sustainable and better able to withstand shocks like the COVID‐19 pandemic and can be significant contributors to community resilience. We conclude with a series of future research priorities critical to examine a largely unexplored nexus in the private sector, the linkages and dynamics between sustainability practice, resilience building, and broader community pathways. [ABSTRACT FROM AUTHOR]

Background: Using the spin‐lattice relaxation time (T1) as a biomarker, the myocardium can be quantitatively characterized using cardiac T1 mapping. The modified Look–Locker inversion (MOLLI) recovery sequences have become the standard clinical method for cardiac T1 mapping. However, the MOLLI sequences require an 11‐heartbeat breath‐hold that can be difficult for subjects, particularly during exercise or pharmacologically induced stress. Although shorter cardiac T1 mapping sequences have been proposed, these methods suffer from reduced precision. As such, there is an unmet need for accelerated cardiac T1 mapping. Purpose: To accelerate cardiac T1 mapping MOLLI sequences by using neural networks to estimate T1 maps using a reduced number of T1‐weighted images and their corresponding inversion times. Materials and Methods: In this retrospective study, 911 pre‐contrast T1 mapping datasets from 202 subjects (128 males, 56 ± 15 years; 74 females, 54 ± 17 years) and 574 T1 mapping post‐contrast datasets from 193 subjects (122 males, 57 ± 15 years; 71 females, 54 ± 17 years) were acquired using the MOLLI‐5(3)3 sequence and the MOLLI‐4(1)3(1)2 sequence, respectively. All acquisition protocols used similar scan parameters: TR=2.2ms$TR\; = \;2.2\;{\rm{ms}}$, TE=1.12ms$TE\; = \;1.12\;{\rm{ms}}$, and FA=35∘$FA\; = \;35^\circ $, gadoteridol (ProHance, Bracco Diagnostics) dose ∼0.075mmol/kg$\sim 0.075\;\;{\rm{mmol/kg}}$. A bidirectional multilayered long short‐term memory (LSTM) network with fully connected output and cyclic model‐based loss was used to estimate T1 maps from the first three T1‐weighted images and their corresponding inversion times for pre‐ and post‐contrast T1 mapping. The performance of the proposed architecture was compared to the three‐parameter T1 recovery model using the same reduction of the number of T1‐weighted images and inversion times. Reference T1 maps were generated from the scanner using the full MOLLI sequences and the three‐parameter T1 recovery model. Correlation and Bland–Altman plots were used to evaluate network performance in which each point represents averaged regions of interest in the myocardium corresponding to the standard American Heart Association 16‐segment model. The precision of the network was examined using consecutively repeated scans. Stress and rest pre‐contrast MOLLI studies as well as various disease test cases, including amyloidosis, hypertrophic cardiomyopathy, and sarcoidosis were also examined. Paired t‐tests were used to determine statistical significance with p<0.05$p < 0.05$. Results: Our proposed network demonstrated similar T1 estimations to the standard MOLLI sequences (pre‐contrast: 1260±94ms$1260 \pm 94\;{\rm{ms}}$ vs. 1254±91ms$1254 \pm 91\;{\rm{ms}}$ with p=0.13$p\; = \;0.13$; post‐contrast: 484±92ms$484 \pm 92\;{\rm{ms}}$ vs. 493±91ms$493 \pm 91\;{\rm{ms}}$ with p=0.07$p\; = \;0.07$). The precision of standard MOLLI sequences was well preserved with the proposed network architecture (24±28ms$24 \pm 28\;\;{\rm{ms}}$ vs. 18±13ms$18 \pm 13\;{\rm{ms}}$). Network‐generated T1 reactivities are similar to stress and rest pre‐contrast MOLLI studies (5.1±4.0%$5.1 \pm 4.0\;\% $ vs. 4.9±4.4%$4.9 \pm 4.4\;\% $ with p=0.84$p\; = \;0.84$). Amyloidosis T1 maps generated using the proposed network are also similar to the reference T1 maps (pre‐contrast: 1243±140ms$1243 \pm 140\;\;{\rm{ms}}$ vs. 1231±137ms$1231 \pm 137\;{\rm{ms}}$ with p=0.60$p\; = \;0.60$; post‐contrast: 348±26ms$348 \pm 26\;{\rm{ms}}$ vs. 346±27ms$346 \pm 27\;{\rm{ms}}$ with p=0.89$p\; = \;0.89$). Conclusions: A bidirectional multilayered LSTM network with fully connected output and cyclic model‐based loss was used to generate high‐quality pre‐ and post‐contrast T1 maps using the first three T1‐weighted images and their corresponding inversion times. This work demonstrates that combining deep learning with cardiac T1 mapping can potentially accelerate standard MOLLI sequences from 11 to 3 heartbeats. [ABSTRACT FROM AUTHOR]

Posttranscriptional regulation by microRNA (miRNA) facilitates exercise and diet-induced skeletal muscle adaptations. However, the impact of diet on miRNA expression during postexercise recovery remains unclear. The objective of this study was to examine the effects of consuming carbohydrate or a nutrient-free control on skeletal muscle miRNA expression during 3 h of recovery from aerobic exercise. Using a randomized, crossover design, seven men (means ± SD, age: 21 ± 3 yr; body mass: 83 ± 13 kg; VO2peak: 43±2 mL/kg/min) completed two-cycle ergometry glycogen depletion trials followed by 3 h of recovery while consuming either carbohydrate (CHO: 1 g/kg/h) or control (CON: nutrient free). Muscle biopsy samples were obtained under resting fasted conditions at baseline and at the end of the 3-h recovery (REC) period. miRNA expression was determined using unbiased RT-qPCR microarray analysis. Trials were separated by 7 days. Twenty-five miRNAs were different (P < 0.05) between CHO and CON at REC, with Let7i-5p and miR-195-5p being the most predictive of treatment. In vitro overexpression of Let7i-5p and miR-195-p5 in C2C12 skeletal muscle cells decreased (P < 0.05) the expression of protein breakdown (Foxo1, Trim63, Casp3, and Atf4) genes, ubiquitylation, and protease enzyme activity compared with control. Energy sensing (Prkaa1 and Prkab1) and glycolysis (Gsy1 and Gsk3b) genes were lower (P < 0.05) with Let7i-5p overexpression compared with miR-195-5p and control. Fat metabolism (Cpt1a, Scd1, and Hadha) genes were lower (P < 0.05) in miR-195-5p than in control. These data indicate that consuming CHO after aerobic exercise alters miRNA profiles compared with CON, and these differences may govern mechanisms facilitating muscle recovery. [ABSTRACT FROM AUTHOR]

A number of philosophers have thought that fair lotteries over countably infinite sets of outcomes are conceptually incoherent by virtue of violating countable additivity. In this article, I show that a qualitative analogue of this argument generalizes to an argument against the conceptual coherence of a much wider class of fair infinite lotteries—including continuous uniform distributions. I argue that this result suggests that fair lotteries over countably infinite sets of outcomes are no more conceptually problematic than continuous uniform distributions. Along the way, I provide a novel argument for a weak qualitative, epistemic version of regularity. [ABSTRACT FROM AUTHOR]

MicroRNAs (miRNAs) regulate molecular processes governing muscle metabolism. Physical activity and energy balance influence both muscle anabolism and substrate metabolism, but whether circulating and skeletal muscle miRNAs mediate those effects remains unknown. This study assessed the impact of sustained physical activity with participants in energy balance (BAL) or deficit (DEF) on circulating and skeletal muscle miRNAs. Using a randomized cross‐over design, 10 recreational active healthy males (mean ± SD, 22 ± 5 years, 87 ± 11 kg) completed 72 h of high aerobic exercise‐induced energy expenditures in BAL (689 ± 852 kcal/day) or DEF (−2047 ± 920 kcal/day). Blood and muscle samples were collected under rested/fasted conditions before (PRE) and immediately after 120 min load carriage exercise bout at the end (POST) of the 72 h. Trials were separated by 7 days. Circulating and skeletal muscle miRNAs were measured using microarray RT‐qPCR. Independent of energy status, 36 circulating miRNAs decreased (P < 0.05), while 10 miRNAs increased and three miRNAs decreased in skeletal muscle (P < 0.05) at POST compared to PRE. Of these, miR‐122‐5p, miR‐221‐3p, miR‐222‐3p and miR‐24‐3p decreased in circulation and increased in skeletal muscle. Two circulating (miR‐145‐5p and miR‐193a‐5p) and four skeletal muscle (miR‐21‐5p, miR‐372‐3p, miR‐34a‐5p and miR‐9‐5p) miRNAs had time‐by‐treatment effects (P < 0.05). These data suggest that changes in miRNA profiles are more sensitive to increased physical activity compared to energy status, and that changes in circulating miRNAs in response to high levels of daily aerobic exercise are not reflective of changes in skeletal muscle miRNAs. Key points: Circulating and skeletal muscle miRNA profiles are more sensitive to high levels of aerobic exercise‐induced energy expenditure compared to energy status.Changes in circulating miRNA in response to high levels of daily sustained aerobic exercise are not reflective of changes in skeletal muscle miRNA. [ABSTRACT FROM AUTHOR]

The unfolding COVID-19 pandemic, and the unprecedented social and economic costs it has inflicted, provide an important opportunity to scrutinize the interplay between the resilience of small and medium-sized enterprises (SMEs) and the resilience of the communities they are embedded in. In this article, we articulate the specific ways that SMEs play a crucial, and underappreciated role in building resilience to human and natural hazards, and provide new opportunities to accelerate the adoption of sustainability practices through the configuration of 'enabling ecosystems' geared towards promoting sustainability in the private sector. We argue that capacity-building and experimentation are not only required within companies, but also throughout this emerging supportive ecosystem of policies, resources (i.e. finance, materials, skills), governance actors, and intermediaries to adequately focus investment, technical capabilities and innovation. Ultimately, we call for a new transdisciplinary action research agenda that centers on SMEs as pivotal actors and amplifiers of community resilience; while recognizing that these firms are themselves in need of support to secure their own capacity to respond to, and transform in light of, crises. This research program calls for recognizing and applying the lessons that the pandemic presents to the urgent need for accelerated climate action. This will be enabled by developing more targeted approaches to collaborative capacity-building activities in SMEs that feed into experimentation and allow for the accelerated adoption of deliberate and strategic resilient business practices and models. [ABSTRACT FROM AUTHOR]

Purpose: While advanced diffusion techniques have been found valuable in many studies, their clinical availability has been hampered partly due to their long scan times. Moreover, each diffusion technique can only extract a few relevant microstructural features. Using multiple diffusion methods may help to better understand the brain microstructure, which requires multiple expensive model fittings. In this work, we compare deep learning (DL) approaches to jointly estimate parametric maps of multiple diffusion representations/models from highly undersampled q‐space data. Methods: We implement three DL approaches to jointly estimate parametric maps of diffusion tensor imaging (DTI), diffusion kurtosis imaging (DKI), neurite orientation dispersion and density imaging (NODDI), and multi‐compartment spherical mean technique (SMT). A per‐voxel q‐space deep learning (1D‐qDL), a per‐slice convolutional neural network (2D‐CNN), and a 3D‐patch‐based microstructure estimation with sparse coding using a separable dictionary (MESC‐SD) network are considered. Results: The accuracy of estimated diffusion maps depends on the q‐space undersampling, the selected network architecture, and the region and the parameter of interest. The smallest errors are observed for the MESC‐SD network architecture (less than 10% normalized RMSE in most brain regions). Conclusion: Our experiments show that DL methods are very efficient tools to simultaneously estimate several diffusion maps from undersampled q‐space data. These methods can significantly reduce both the scan (∼6‐fold) and processing times (∼25‐fold) for estimating advanced parametric diffusion maps while achieving a reasonable accuracy. [ABSTRACT FROM AUTHOR]

Objective: This study aims to examine the use of decision aids which may improve shared decision making through an exploration of risk apprehension and modes of collaborative communication. Conclusions: Decision aids such as graphics have a key role in facilitating shared treatment decision making, perhaps particularly in perinatal mental health care. They are most useful within a trusting, two-way conversation. [ABSTRACT FROM AUTHOR]

We previously demonstrated that intake of three eggs/d for 4 weeks increased plasma choline and decreased inflammation in subjects with metabolic syndrome (MetS). The purpose of the current study was to further explore the effects of phosphatidylcholine (PC) provided by eggs versus a choline bitartrate (CB) supplement on the gut microbiota, trimethylamine N-oxide (TMAO) formation, and plasma carotenoids lutein and zeaxanthin in MetS. This randomized, controlled crossover clinical trial included 23 subjects with MetS. Following a washout period of 2 weeks without consuming any choline-containing foods, subjects were randomly allocated to consume either three eggs/d or a CB supplement for 4 weeks (both diets had a choline equivalent of 400 mg/day). DNA was extracted from stool samples to sequence the 16S rRNA gene region for community analysis. Operational taxonomic units (OTUs) and the α-diversity of the community were determined using QIIME software. Plasma TMAO, methionine, betaine, and dimethylglycine (DMG) were quantified by stable isotope dilution liquid chromatography with tandem mass spectrometry. Plasma carotenoids, lutein, and zeaxanthin were measured using reversed-phase high-performance liquid chromatography. There were significant increases in plasma lutein and zeaxanthin after egg intake compared to the baseline or intake of CB supplement (p < 0.01). In contrast, TMAO was not different between treatments compared to the baseline (p > 0.05). Additionally, while diet intervention had no effects on microbiota diversity measures or relative taxa abundances, a correlation between bacterial biodiversity and HDL was observed. Following egg intake, the observed increases in plasma lutein and zeaxanthin may suggest additional protection against oxidative stress, a common condition in MetS. [ABSTRACT FROM AUTHOR]

Bogotch (2002) proposed that educational leadership cannot be separated from social justice, and this is a sentiment that is taken to heart at an urban Title-1 school district in Houston, Texas. To intentionally address the need for such alignment between mission and practice, the district implemented a recruitment and talent development initiative that actively sought to change the district's talent pool. This program develops effective leaders through a fellowship that focuses on building and leading an effective team, coaching and managing with excellence, and solving high-impact, complex problems. Using a position- subject approach (Conrad, Haworth, & Millar, 2001), this paper evaluates the extent to which the program uplifts diverse voices in school leadership and the extent to which the program successfully prepares participants for leadership roles. This manuscript includes a description of a successful and inclusive school leadership pipeline, an explanation of challenges and resistance faced for both leadership initiatives, and strategies to continue growth in this particular area of educational leadership through data collected via survey, interview, and autoethnographic reflections. [ABSTRACT FROM AUTHOR]

Over 1 billion people are living at the frontlines of climate change in mountain areas, where warming rates outpace the global average and are driving significant changes in environments and ecosystem services. These changes are exacerbating socioeconomic difficulties faced by many mountain communities, and are already intensifying vulnerabilities across mountain areas globally. The situation is indicative of pervasive and consequential deficits in adaptation, and calls attention to the need for a better understanding of existing adaptation efforts, as well as the prospects for increasing the quantity and quality of adaptation action in mountain regions. In response, this MountainAgenda article introduces a conceptual framework for adaptation gaps. It then uses data from 2 major global-scale adaptation reviews to shed light on the nature and true magnitude of the adaptation gap in mountains. It reveals shortcomings in available adaptation options, deficits in the uptake of existing adaptation support, and a general lack of coherence between existing adaptations and keystone global agreements relevant to climate change adaptation. These shortcomings are largely related to soft limits to adaptation that constrain responses across mountain areas. In this article, we provide recommendations for closing the adaptation gap in mountains and suggest that this will require deeply collaborative efforts that are rooted in local needs, aspirations, and ways of knowing, but that are also supported by external capacity building and implementation resources. In many instances, this will resemble a transformative approach to adaptation. The conceptual framework presented here is broadly applicable and can also be utilized to identify and close adaptation gaps in social-ecological contexts beyond mountains. [ABSTRACT FROM AUTHOR]

This work describes an exploratory experimental and in silico study of the influence of polymorphism, particle size, and physiology on the pharmacokinetics of lercanidipine hydrochloride (LHC). Equilibrium and kinetic solubility studies were performed on LHC forms I and II, as a function of pH and buffer composition. GastroPlus® was used to evaluate the potential effect of solubility differences due to polymorphism, particle size, and physiological conditions, on the drug pharmacokinetics. The results indicated that solubilities of LHC polymorphs are strongly dependent on the composition and pH of the buffer media. The concentration ratio (CI/CII) is particularly large for chloride buffer (CI/CII = 3.3–3.9) and exhibits a slightly decreasing tendency with the pH increase for all other buffers. Based on solubility alone, a higher bioavailability of form I might be expected. However, exploratory PBPK simulations suggested that (i) under usual fasted (pH 1.3) and fed (pH 4.9) gastric conditions, the two polymorphs have similar bioavailability, regardless of the particle size; (ii) at high gastric pH in the fasted state (e.g., pH 3.0), the bioavailability of form II can be considerably lower than that of form I, unless the particle size is < 20 μm. This study demonstrates the importance of investigating the effect of the buffer nature when evaluating the solubility of ionizable polymorphic substances. It also showcases the benefits of using PBPK simulations, to assess the risk and pharmacokinetic relevance of different solubility and particle size between crystal forms, for diverse physiological conditions. [ABSTRACT FROM AUTHOR]

Purpose: To develop a whole‐heart, free‐breathing, non‐electrocardiograph (ECG)‐gated, cardiac‐phase‐resolved myocardial perfusion MRI framework (CRIMP; Continuous Radial Interleaved simultaneous Multi‐slice acquisitions at sPoiled steady‐state) and test its quantification feasibility. Methods: CRIMP used interleaved radial simultaneous multi‐slice (SMS) slice groups to cover the whole heart in 9 or 12 short‐axis slices. The sequence continuously acquired data without magnetization preparation, ECG gating or breath‐holding, and captured multiple cardiac phases. Images were reconstructed by a motion‐compensated patch‐based locally low‐rank reconstruction. Bloch simulations were performed to study the signal‐to‐noise ratio/contrast‐to‐noise ratio (SNR/CNR) for CRIMP and to study the steady‐state signal under motion. Seven patients were scanned with CRIMP at stress and rest to develop the sequence. One human and two dogs were scanned at rest with a dual‐bolus method to test the quantification feasibility of CRIMP. The dual‐bolus scans were performed using both CRIMP and an ungated radial SMS saturation recovery (SMS‐SR) sequence with injection dose = 0.075 mmol/kg to compare the sequences in terms of SNR, cardiac phase resolution and quantitative myocardial blood flow (MBF). Results: Perfusion images with multiple cardiac phases in all image slices with a temporal resolution of 72 ms/frame were obtained. Simulations and in‐vivo acquisitions showed CRIMP kept the inner slices in steady‐state regardless of motion. CRIMP outperformed SMS‐SR in slice coverage (9 over 6), SNR (mean 20% improvement), and provided cardiac phase resolution. CRIMP and SMS‐SR sequences provided comparable MBF values (rest systolic CRIMP = 0.58 ± 0.07, SMS‐SR = 0.61 ± 0.16). Conclusion: CRIMP allows for whole‐heart, cardiac‐phase‐resolved myocardial perfusion images without ECG‐gating or breath‐holding. The sequence can provide MBF if an accurate arterial input function is obtained separately. [ABSTRACT FROM AUTHOR]

Introduction: Late gadolinium enhancement (LGE) cardiac magnetic resonance imaging (MRI) can be used to detect postablation atrial scar (PAAS) but its reproducibility and reliability in clinical scans across different magnetic flux densities and scar detection methods are unknown. Methods: Patients (n = 45) having undergone two consecutive MRIs (3 months apart) on 3T and 1.5T scanners were studied. We compared PAAS detection reproducibility using four methods of thresholding: simple thresholding, Otsu thresholding, 3.3 standard deviations (SD) above blood pool (BP) mean intensity, and image intensity ratio (IIR). We performed a texture study by dividing the left atrial wall intensity histogram into deciles and evaluated the correlation of the same decile of the two scans as well as to a randomized distribution of intensities, quantified using Dice Similarity Coefficient (DSC). Results: The choice of scanner did not significantly affect the reproducibility. The scar detection performed by Otsu thresholding (DSC of 71.26 ± 8.34) resulted in a better correlation of the two scans compared with the methods of 3.3 SD above BP mean intensity (DSC of 57.78 ± 21.2, p <.001) and IIR above 1.61 (DSC of 45.76 ± 29.55, p <.001). Texture analysis showed that correlation only for voxels with intensities in deciles above the 70th percentile of wall intensity histogram was better than random distribution (p <.001). Conclusions: Our results demonstrate that clinical LGE‐MRI can be reliably used for visualizing PAAS across different magnetic flux densities if the threshold is greater than 70th percentile of the wall intensity distribution. Also, atrial wall‐based thresholding is better than BP‐based thresholding for reproducible PAAS detection. [ABSTRACT FROM AUTHOR]

Objective: Myocardial first-pass perfusion imaging with MRI is well-established clinically. However, it is potentially weakened by limited myocardial coverage compared to nuclear medicine. Clinical evaluations of whole-heart MRI perfusion by 3D methods, while promising, have to date had the limit of breathhold requirements at stress. This work aims to develop a new free-breathing 3D myocardial perfusion method, and to test its performance in a small patient population. Methods: This work required tolerance to respiratory motion for stress investigations, and therefore employed a "stack-of-stars" hybrid Cartesian-radial MRI acquisition method. The MRI sequence was highly optimised for rapid acquisition and combined with a compressed sensing reconstruction. Stress and rest datasets were acquired in four healthy volunteers, and in six patients with coronary artery disease (CAD), which were compared against clinical reference information. Results: This free-breathing method produced datasets that appeared consistent with clinical reference data in detecting moderate-to-strong induced perfusion abnormalities. However, the majority of the mild defects identified clinically were not detected by the method, potentially due to the presence of transient myocardial artefacts present in the images. Discussion: The feasibility of detecting CAD using this 3D first-pass perfusion sequence during free-breathing is demonstrated. Good agreement on typical moderate-to-strong CAD cases is promising, however, questions still remain on the sensitivity of the technique to milder cases. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to further develop and combine several innovative sequence designs to achieve quantitative 3D myocardial perfusion. These developments include an optimized 3D stack‐of‐stars readout (150 ms per beat), efficient acquisition of a 2D arterial input function, tailored saturation pulse design, and potential whole heart coverage during quantitative stress perfusion. Theory and Methods: All studies were performed free‐breathing on a Prisma 3T MRI scanner. Phantom validation was used to verify sequence accuracy. A total of 21 subjects (3 patients with known disease) were scanned, 12 with a rest only protocol and 9 with both stress (regadenoson) and rest protocols. First pass quantitative perfusion was performed with gadoteridol (0.075 mmol/kg). Results: Implementation and quantitative perfusion results are shown for healthy subjects and subjects with known coronary disease. Average rest perfusion for the 15 included healthy subjects was 0.79 ± 0.19 mL/g/min, the average stress perfusion for 6 healthy subject studies was 2.44 ± 0.61 mL/g/min, and the average global myocardial perfusion reserve ratio for 6 healthy subjects was 3.10 ± 0.24. Perfusion deficits for 3 patients with ischemia are shown. Average resting heart rate was 59 ± 7 bpm and the average stress heart rate was 81 ± 10 bpm. Conclusion: This work demonstrates that a quantitative 3D myocardial perfusion sequence with the acquisition of a 2D arterial input function is feasible at high stress heart rates such as during stress. T1 values and gadolinium concentrations of the sequence match the reference standard well in a phantom, and myocardial rest and stress perfusion and myocardial perfusion reserve values are consistent with those published in literature. [ABSTRACT FROM AUTHOR]

Climate change adaptation requires organizations to recognize the numerous natural and social dimensions of climate risk. In the private sector, local adaptation responses to climate change are observed as changes to the limited capacities of organizational processes to plan for social aspects of adaptation. This article applies a methodology to map these connections and presents empirical evidence of a firm's autonomous adaptation measures along their supply chain in Baja California, Mexico. The spatial conceptualization of the business model illustrates the potential to identify sources of climate‐related risks, autonomous adaptation actions, and the barriers to improving the feedback loops to facilitate the integration of local knowledge for business model innovation. The results suggest that coproduction of innovations is a mechanism for organizational learning that can help to overcome the challenges for business strategy to identify the wide array of local factors associated to climate adaptation and normalize adaptation planning into business models. This approach might accelerate leveraging the capabilities of the private sector for socially oriented forms of adaptation that amplify the transformational value of business model approaches for improved adaptation strategies. [ABSTRACT FROM AUTHOR]

Ameliorating biological attributes of agricultural soils is desirable, and one avenue is introducing beneficial microbes via commercial biostimulant products. Although gaining popularity with farmers, scientific evaluation of such products in field-grown crops is often lacking. We tested two microbial products, Soil-Life™ and Nutri-Life Platform®, in a commercial sugarcane crop by profiling bacterial and fungal communities in soil and roots using high throughput phylogenetic marker gene sequencing. The products, one predominantly consisting of Lactobacillus and the other of Trichoderma, were applied as a mixture as per manufacturers' instructions. Additives included in the formulations were not listed, and plots that did not receive the product mixture were the controls. The compositions of bacterial communities of soil and sugarcane roots, sampled 2, 5 and 25 weeks after application, were unaffected by the products. Soil fungal communities were also unaffected, but sugarcane roots had a greater relative abundance of three unidentified taxa in genera Marasmius, Fusarium and Talaromyces in the treated plots. Sugarcane yield was similar across all treatments that included a 25% lower nitrogen fertiliser rate. Further research must examine if the altered root fungal community is a consistent feature of the tested products, and if it conveys benefits. We conclude that putative biostimulants can be evaluated by analysing the composition of microbial communities. DNA profiling should be complemented by cost-benefit analysis to build a public information base documenting the effects of microbial biostimulants. Such knowledge will assist manufacturers in product development and farmers in making judicious decisions on product selection, to ensure that the anticipated benefits of microbial biostimulants are realised for broad acre cropping. [ABSTRACT FROM AUTHOR]

The state-of-the-art approaches for image reconstruction using under-sampled k-space data are compressed sensing based. They are iterative algorithms that optimize objective functions with spatial and/or temporal constraints. This paper proposes a non-iterative algorithm to estimate the un-measured data and then to reconstruct the image with the efficient filtered backprojection algorithm. The feasibility of the proposed method is demonstrated with a patient magnetic resonance imaging study. The proposed method is also compared with the state-of-the-art iterative compressed-sensing image reconstruction method using the total-variation optimization norm. [ABSTRACT FROM AUTHOR]

Introduction: The aim of this study was to compare long‐term outcomes in patients who underwent either native tissue repair or monofilament macroporous polypropylene mesh. Methods: This multicenter, randomized trial included—at the end of 5 years follow‐up—122 women with severe pelvic organ prolapse, who were randomly assigned to undergo surgical treatment using native tissue repair (native tissue group, n = 59) or synthetic mesh repair (mesh group, n = 63). Cure criterion was when pelvic organ prolapse‐quantification (POP‐Q) point was ≤0. Quality of life was assessed using the prolapse quality‐of‐life questionnaire and sexual function with the quality of sexual function. Results: Groups were homogeneous preoperatively with the exception of the previous pelvic surgery variable, which was higher in mesh (P =.019). Cure rate was significantly better for mesh group in the anterior compartment (P =.002) and in the combination of all compartments (P =.001). Native tissue group was significantly better when there was prolapse in the posterior and apical compartment (P =.031). In the quality of life analysis, mesh group showed a significant improvement compared with native tissue group (P =.004). Complications were significantly higher in mesh and recurrence in native tissue. Regarding the reoperation rate, there was no difference between groups, but native tissue had a higher reoperation rate due to recurrence (P =.031). Conclusions: Outcomes in women with severe POP were better with mesh use than native tissue repair, both in the anterior compartment and in the multicompartmental prolapse after 5‐year follow‐up. Complications were more common in the mesh group and recurrences were more frequent in the native tissue group. [ABSTRACT FROM AUTHOR]

We compared maximal exercise parameters obtained using both a ramped Bruce (BR) and a standard Bruce treadmill protocol (BS) in 44 healthy children (9.9 +/- 1.9 yr) and adolescents (15.9 +/- 1.7 yr). The average weight and height for children was 36.7 +/- 10.7 kg and 141.2 +/- 13.2 cm, while for adolescents was 64.4 +/- 13.9 kg and 168.9 +/- 7.5 cm. No significant differences were found in peak heart rate (HRpeak) between protocols for children (BS: 198 +/- 10; BR: 196 +/- 11 bpm) or adolescents (BS:193 +/- 2; BR:192 +/- 11 bpm). Peak oxygen uptake (VO2peak) was also not significantly different for children (BS: 1.81 +/- 0.64; BR: 1.84 +/- 0.74 L/min) or adolescents (BS: 2.66 +/- 0.61; BR: 2.72 +/- 0.67 L/min). Based on our results, we conclude that equivalent peak HR and VO2 values can be obtained in normal children and adolescents using a standard or a ramped Bruce protocol. [ABSTRACT FROM AUTHOR]

We compared maximal exercise parameters obtained using both a ramped Bruce (BR) and a standard Bruce treadmill protocol (BS) in 44 healthy children (9.9 ± 1.9 yr) and adolescents (15.9 ± 1.7 yr). The average weight and height for children was 36.7 ± 10.7 kg and 141.2 ± 13.2 cm, while for adolescents was 64.4 ± 13.9 kg and 168.9 ± 7.5 cm. No significant differences were found in peak heart rate (HR[sub peak]) between protocols for children (BS: 198 ± 10; BR: 196 ± 11 bpm) or adolescents (BS:193 ± 2; BR: 192 ± 11 bpm). Peak oxygen uptake (VO[sub 2peak]) was also not significantly different for children (BS: 1.81 ± 0.64; BR: 1.84 ± 0.74 L/min) or adolescents (BS: 2.66 ± 0.61; BR: 2.72 ± 0.67 L/min). Based on our results, we conclude that equivalent peak HR and ...O[sub 2] values can be obtained in normal children and adolescents using a standard or a ramped Bruce protocol. [ABSTRACT FROM AUTHOR]

Co-inhibitory immune receptors can contribute to T cell dysfunction in patients with cancer1,2. Blocking antibodies against cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) and programmed cell death 1 (PD-1) partially reverse this effect and are becoming standard of care in an increasing number of malignancies3. However, many of the other axes by which tumours become inhospitable to T cells are not fully understood. Here we report that V-domain immunoglobulin suppressor of T cell activation (VISTA) engages and suppresses T cells selectively at acidic pH such as that found in tumour microenvironments. Multiple histidine residues along the rim of the VISTA extracellular domain mediate binding to the adhesion and co-inhibitory receptor P-selectin glycoprotein ligand-1 (PSGL-1). Antibodies engineered to selectively bind and block this interaction in acidic environments were sufficient to reverse VISTA-mediated immune suppression in vivo. These findings identify a mechanism by which VISTA may engender resistance to anti-tumour immune responses, as well as an unexpectedly determinative role for pH in immune co-receptor engagement. V-domain immunoglobulin suppressor of T cell activation (VISTA) selectively engages P-selectin glycoprotein ligand-1 (PSGL-1) and suppresses T cells at acidic pH similar to those in tumour microenvironments, thereby mediating resistance to anti-tumour immune responses. [ABSTRACT FROM AUTHOR]

Purpose : To develop a robust multidimensional deep‐learning based method to simultaneously generate accurate neurite orientation dispersion and density imaging (NODDI) and generalized fractional anisotropy (GFA) parameter maps from undersampled q‐space datasets for use in stroke imaging. Methods : Traditional diffusion spectrum imaging (DSI) capable of producing accurate NODDI and GFA parameter maps requires hundreds of q‐space samples which renders the scan time clinically untenable. A convolutional neural network (CNN) was trained to generated NODDI and GFA parameter maps simultaneously from 10× undersampled q‐space data. A total of 48 DSI scans from 15 stroke patients and 14 normal subjects were acquired for training, validating, and testing this method. The proposed network was compared to previously proposed voxel‐wise machine learning based approaches for q‐space imaging. Network‐generated images were used to predict stroke functional outcome measures. Results : The proposed network achieves significant performance advantages compared to previously proposed machine learning approaches, showing significant improvements across image quality metrics. Generating these parameter maps using CNNs also comes with the computational benefits of only needing to generate and train a single network instead of multiple networks for each parameter type. Post‐stroke outcome prediction metrics do not appreciably change when using images generated from this proposed technique. Over three test participants, the predicted stroke functional outcome scores were within 1–6% of the clinical evaluations. Conclusions : Estimates of NODDI and GFA parameters estimated simultaneously with a deep learning network from highly undersampled q‐space data were improved compared to other state‐of‐the‐art methods providing a 10‐fold reduction scan time compared to conventional methods. [ABSTRACT FROM AUTHOR]

Improved understanding of neuroimaging signal changes and their relation to patient outcomes after ischemic stroke is needed to improve ability to predict motor improvement and make therapy recommendations. The posterior limb of the internal capsule (PLIC) is a hub of afferent and efferent motor signaling and this work proposes new, image-based methods for prognosis based on interhemispheric differences in the PLIC. In this work, nine acute supratentorial ischemic stroke patients with motor impairment received a baseline, 203-direction diffusion brain MRI and a clinical assessment 3–12 days post-stroke and were compared to nine age-matched healthy controls. Asymmetries based on the mean and Kullback-Leibler divergence in the ipsilesional and contralesional PLIC were calculated for diffusion tensor imaging (DTI) and diffusion spectrum imaging (DSI) measures from the baseline MRI. Predictions of upper extremity Fugl-Meyer (FM) scores at 5-weeks follow-up from baseline measures of PLIC asymmetry in diffusion tensor imaging (DTI) and diffusion spectrum imaging (DSI) models were evaluated. For the stroke participants, the baseline asymmetry measures in the PLIC for the orientation dispersion index of the neurite orientation dispersion and density imaging (NODDI) model were highly correlated with upper extremity FM outcomes (r 2 = 0.83). Use of DSI and the NODDI orientation dispersion index parameter shows promise of being more predictive of stroke recovery and to help better understand white matter changes in stroke, beyond DTI measures. The new finding that baseline interhemispheric differences in the PLIC calculated from the orientation dispersion index of the NODDI model are highly correlated with upper extremity functional outcomes may lead to improved image-based motor-outcome prediction after middle cerebral artery ischemic stroke. [ABSTRACT FROM AUTHOR]

Purpose: Dynamic contrast enhanced MRI of the heart typically acquires 2–4 short-axis (SA) slices to detect and characterize coronary artery disease. This acquisition scheme is limited by incomplete coverage of the left ventricle. We studied the feasibility of using radial simultaneous multi-slice (SMS) technique to achieve SA, 2-chamber and/or 4-chamber long-axis (2CH LA and/or 4CH LA) coverage with and without electrocardiography (ECG) gating using a motion-robust reconstruction framework. Methods: 12 subjects were scanned at rest and/or stress, free breathing, with or without ECG gating. Multiple sets of radial SMS k-space were acquired within each cardiac cycle, and each SMS set sampled 3 parallel slices that were either SA, 2CH LA, or 4CH LA slices. The radial data was interpolated onto Cartesian space using an SMS GRAPPA operator gridding method. Self-gating and respiratory states binning of the data were done. The binning information as well as a pixel tracking spatiotemporal constrained reconstruction method were applied to obtain motion-robust image reconstructions. Reconstructions with and without the pixel tracking method were compared for signal-to-noise ratio and contrast-to-noise ratio. Results: Full coverage of the heart (at least 3 SA and 3 LA slices) during the first pass of contrast at every heartbeat was achieved by using the radial SMS acquisition. The proposed pixel tracking reconstruction improves the average SNR and CNR by 21% and 30% respectively, and reduces temporal blurring for both gated and ungated acquisitions. Conclusion: Acquiring simultaneous multi-slice SA, 2CH LA and/or 4CH LA myocardial perfusion images in every heartbeat is feasible in both gated and ungated acquisitions. This can add confidence when detecting and characterizing coronary artery disease by revealing ischemia in different views, and by providing apical coverage that is improved relative to SA slices alone. The proposed pixel tracking framework improves the reconstruction while adding little computational cost. [ABSTRACT FROM AUTHOR]

Introduction: The purpose of this study was to describe and compare the performance of balance and walking tests in relation to self-reported fall history in adults with myotonic dystrophy type 1 (DM1).Methods: Twenty-two (13 male) participants with DM1 completed, a 6-month fall history questionnaire, the modified Dynamic Gait Index (mDGI), limits of stability (LoS) testing, and 10-m walking tests.Results: Mean (SD) falls in 6 months was 3.7 (3.1), and 19 (86%) participants reported at least 1 fall. Significant differences in mDGI scores (P = 0.006) and 10-m fast walking gait velocity (P = 0.02) were found between those who had been classified as "fallers" and those who had been classified as "nonfallers." Significant correlations were found between mDGI scores and 10-m walking time.Discussion: Falls are common in DM1, and the mDGI may have potential to distinguish fallers from nonfallers, whereas the LoS failed to detect such impairment. Future studies should further explore use of the mDGI in DM1. Muscle Nerve 58: 694-699, 2018. [ABSTRACT FROM AUTHOR]

Purpose: MRI or CT imaging can be used to identify the esophageal location prior to left atrial ablation, but the esophagus may move making the location unreliable when ablating to minimize esophageal injury. The aim of this study was to evaluate esophageal position and movement based on serial MRI imaging with the goal of identifying imaging and clinical characteristics that can predict the esophageal movement.Methods: Fifty patients undergoing 190 MRI scans were analyzed. The relative position of the esophagus in each MRI along with clinical and imaging characteristics was quantified, including the gap between the left atrium (LA) and the vertebral body (GAP), an anatomic space in which the esophagus can move.Results: A mean of 3.8 MRIs was analyzed per patient. Sixteen patients (32.0%) experienced significant lateral esophageal movement of more than 10 mm. In the significant movement group, body mass index (BMI) was higher (33.0 ± 6.5 vs 28.8 ± 5.3, p = 0.02) and the GAP was significantly larger (7.1 ± 2.5 vs 4.8 ± 5.1 mm, p = 0.04). Multivariate logistic regression analysis revealed that the GAP ≤ 4.5 mm was the only independent predictor of the esophagus not moving (odds ratio = 9.25, 95% confidence interval = 1.72 to 49.67, p = 0.0095).Conclusions: A GAP of less than 4.5 mm between the LA and the vertebral body is associated with lack of esophageal movement (< 10 mm). This suggests that the measurement of GAP < 4.5 mm may be used to predict the esophageal location in patients undergoing atrial ablation. [ABSTRACT FROM AUTHOR]

Purpose: Golden‐angle radial sparse parallel (GRASP) MRI reconstruction requires gridding and regridding to transform data between radial and Cartesian k‐space. These operations are repeatedly performed in each iteration, which makes the reconstruction computationally demanding. This work aimed to accelerate GRASP reconstruction using self‐calibrating GRAPPA operator gridding (GROG) and to validate its performance in clinical imaging. Methods: GROG is an alternative gridding approach based on parallel imaging, in which k‐space data acquired on a non‐Cartesian grid are shifted onto a Cartesian k‐space grid using information from multicoil arrays. For iterative non‐Cartesian image reconstruction, GROG is performed only once as a preprocessing step. Therefore, the subsequent iterative reconstruction can be performed directly in Cartesian space, which significantly reduces computational burden. Here, a framework combining GROG with GRASP (GROG‐GRASP) is first optimized and then compared with standard GRASP reconstruction in 22 prostate patients. Results: GROG‐GRASP achieved approximately 4.2‐fold reduction in reconstruction time compared with GRASP (∼333 min versus ∼78 min) while maintaining image quality (structural similarity index ≈ 0.97 and root mean square error ≈ 0.007). Visual image quality assessment by two experienced radiologists did not show significant differences between the two reconstruction schemes. With a graphics processing unit implementation, image reconstruction time can be further reduced to approximately 14 min. Conclusion: The GRASP reconstruction can be substantially accelerated using GROG. This framework is promising toward broader clinical application of GRASP and other iterative non‐Cartesian reconstruction methods. Magn Reson Med 80:286–293, 2018. © 2017 International Society for Magnetic Resonance in Medicine. [ABSTRACT FROM AUTHOR]

Purpose: To validate an optimal 12‐fold accelerated real‐time cine MRI pulse sequence with radial k‐space sampling and compressed sensing (CS) in patients at 1.5T and 3T. Methods: We used two strategies to reduce image artifacts arising from gradient delays and eddy currents in radial k‐space sampling with balanced steady‐state free precession readout. We validated this pulse sequence against a standard breath‐hold cine sequence in two patient cohorts: a myocardial infarction (n = 16) group at 1.5T and chronic kidney disease group (n = 18) at 3T. Two readers independently performed visual analysis of 68 cine sets in four categories (myocardial definition, temporal fidelity, artifact, noise) on a 5‐point Likert scale (1 = nondiagnostic, 2 = poor, 3 = adequate or moderate, 4 = good, 5 = excellent). Another reader calculated left ventricular (LV) functional parameters, including ejection fraction. Results: Compared with standard cine, real‐time cine produced nonsignificantly different visually assessed scores, except for the following categories: 1) temporal fidelity scores were significantly lower (P = 0.013) for real‐time cine at both field strengths, 2) artifacts scores were significantly higher (P = 0.013) for real‐time cine at both field strengths, and 3) noise scores were significantly (P = 0.013) higher for real‐time cine at 1.5T. Standard and real‐time cine pulse sequences produced LV functional parameters that were in good agreement (e.g., absolute mean difference in ejection fraction <4%). Conclusion: This study demonstrates that an optimal 12‐fold, accelerated, real‐time cine MRI pulse sequence using radial k‐space sampling and CS produces good to excellent visual scores and relatively accurate LV functional parameters in patients at 1.5T and 3T. Magn Reson Med 79:2745–2751, 2018. © 2017 International Society for Magnetic Resonance in Medicine. [ABSTRACT FROM AUTHOR]