Sustaining altitude pastures in mountain landscapes-a fuzzy cognitive model approach.

Similarly to other European mountain areas, in Serra da Estrela the grazing pressure has been reducing due to social and economic drivers that have pushed shepherds and sheep to the foothill, or plainly out of the sector. Shrub encroachment on commons and other previously grazed land is one of the most tangible effects of pastoral abandonment in Serra de Estrela. The impacts of the resulting increase in landscape continuity and biomass availability were made clear in the severe fires of 2017 and 2022. As fire risk is likely to increase with climate change, it becomes urgent to understand what strategies can be deployed to keep fragmentation in these landscapes. Key actors such as shepherds should be involved in this discussion to understand their perceptions, points of view and reasons for abandoning upland pastures. In this study, we use fuzzy cognitive mapping to identify the key variables and mechanisms affecting the pastoral system according to local shepherds. In our study, we developed with local stakeholders a framework outlining the local pastoral system. Based on that, we carried out the fuzzy cognitive mapping collecting 14 questionnaires. We found that shepherds' income is a central issue, but that it is highly dependent on many factors. Increasing the Common Agricultural Policy payments alone is not enough to incentivise the use of upland pastures. More targeted strategies, such as more support for shrub clearing, and direct payments conditional to transhumance are more impactful. Despite a contentious discourse between conservation and shepherding values in Serra da Estrela, we find that shepherd's values are aligned with biodiversity conservation and a potential nature-based solution for minimizing fire risk through woody fuel management. This opens up possibilities for new governance strategies, that put Serra da Estrela's social, environmental and cultural values at its core.

Myotonic dystrophy type 1 (Steinert disease): 29 years of experience at a tertiary pediatric hospital.

BACKGROUND: Myotonic dystrophy type 1 (DM1) is a multisystemic disorder caused by the expansion of a noncoding triplet repeat. METHODS: A cross-sectional study was performed to characterize pediatric patients with DM1 followed in a tertiary hospital over the last 29 years, comparing the congenital and the childhood/juvenile-onset forms. RESULTS: Thirty-seven patients (59.5 % male) were included, with a median age at the latest assessment of 16.8 years and a median follow-up of 7.7 years. Eleven patients were lost to follow-up, and two died. Twenty-five had congenital DM1 (CDM1), and this form had significantly higher triplet repeat length, history of polyhydramnios, lower median age at diagnosis, and first and last assessment. Common symptoms included distal skeletal muscle weakness (75.7 %) and facial involvement (94.6 %), along with dysphonia/dysarthria (73.0 %) and myotonia (73.0 %). Delayed independent ambulation frequency was significantly higher for CDM1 cases. Skeletal deformities affected 54.1 %, with talipes equinovarus and scoliosis occurring exclusively in CDM1 patients. Cognitive deficit was present in 75.7 % of cases. Polysomnograms revealed seven cases of obstructive sleep apnea and two of hypoventilation. Noninvasive ventilation was used in nine cases, and three had recurrent respiratory infections. The cardiovascular system was affected in 21.6 % of cases. Gastrointestinal issues included constipation (24.3 %), feeding difficulties (16.2 %), and cholelithiasis (5.4 %). Cataracts, epilepsy, and diabetes mellitus were reported in two cases each. CONCLUSION: Our study highlights the diverse spectrum of severity and multiorgan involvement of DM1 in pediatric patients. It underscores the importance of establishing a pediatric-specific standard of care to enhance health outcomes through comprehensive multidisciplinary management.

Farmland expansion and intensification do not foster local food self-sufficiency. Insights from the Mediterranean area.

Bridging the gap between the micro and the macro scale in modelling food security to inform context-specific regionalised policies remains a major scientific challenge. A better understanding of the relations between global and local drivers impacting local food self-sufficiency (LFSS) is essential. We applied to the whole Mediterranean environmental area (Southern and Northern) a modelling framework for structural estimates (PLS-PM) using qualitative and quantitative methods to combine local-level information from field surveys and participatory workshops with global-level data. Our findings show that farmland expansion and intensification spatially disconnected from urban consumption areas do not appear to foster LFSS. On the other hand, public policies appear key to enhancing LFSS in the Mediterranean area if appropriate to the particular regional context. We outline how this multi-level modelling methodology can contribute to a place-based approach by informing context-specific regionalised policies aimed at food security.

Model-based deep learning framework for accelerated optical projection tomography.

In this work, we propose a model-based deep learning reconstruction algorithm for optical projection tomography (ToMoDL), to greatly reduce acquisition and reconstruction times. The proposed method iterates over a data consistency step and an image domain artefact removal step achieved by a convolutional neural network. A preprocessing stage is also included to avoid potential misalignments between the sample center of rotation and the detector. The algorithm is trained using a database of wild-type zebrafish (Danio rerio) at different stages of development to minimise the mean square error for a fixed number of iterations. Using a cross-validation scheme, we compare the results to other reconstruction methods, such as filtered backprojection, compressed sensing and a direct deep learning method where the pseudo-inverse solution is corrected by a U-Net. The proposed method performs equally well or better than the alternatives. For a highly reduced number of projections, only the U-Net method provides images comparable to those obtained with ToMoDL. However, ToMoDL has a much better performance if the amount of data available for training is limited, given that the number of network trainable parameters is smaller.

Varenicline-induced drug eruption: case and review of the literature.

Cutaneous side-effects of varenicline, a selective partial agonist of the a4B2 nicotinic acetylcholine receptor used to treat smoking addiction, are relatively rare and mainly consist of acute generalized exanthematous pustulosis. We describe an atypical clinical presentation of a varenicline-induced drug eruption, which occurred one day after drug initiation. We report this case since we believe no drug reaction to varenicline has had this clinical presentation or rapidity of onset. Clinicians should be aware of this potential adverse cutaneous reaction in patients taking varenicline for smoking cessation.

Adaptation and validation of the Portuguese version of the provider attitudes towards planned home birth (PAPHB) Scale.

Maternity health care professionals' attitudes on the option of home birth can influence the choices and decisions women and their partners make about place of birth. Midwives are particularly influential in this space. The study outlined in this paper aimed to translate and validate the Provider Attitudes towards Planned Home Birth (PAPHB) scale questionnaire for use in the Portuguese maternity context. METHODS: A total of 118 Portuguese midwives were selected through intentional sampling. The procedure was divided into two phases. In the first phase, a triple translation from the original language into Portuguese and a cross-cultural adaptation of the Provider Attitudes towards Planned Home Birth (PAPHB) scale were carried out, obtaining three versions of the same questionnaire. The second phase consisted of the validation of the questionnaire, for which the Provider Attitudes towards Planned Home Birth (PAPHB) scale was submitted to a panel of 20 experts and to a pilot test. Subsequently, the reliability and statistical validity of the scale were evaluated. RESULTS: After content analysis, the results confirmed a four-dimensional structure with a Cronbach's α value of 0.933 for the Provider Attitudes towards Planned Home Birth (PAPHB) scale as a whole, showing good internal consistency. Finally, a bivariate analysis was carried out identifying associations between variables and midwives' attitudes towards home birth. Positive attitudes towards homebirth were strongly influenced by previous clinical experience and exposure to home birth during midwives' academic education. CONCLUSION: The 18-item scale is a reliable and valid tool to quantify attitudes towards planned home births in Portugal as the results obtained in the study showed very good internal consistency.

High-Resolution Free-Breathing Quantitative First-Pass Perfusion Cardiac MR Using Dual-Echo Dixon With Spatio-Temporal Acceleration.

Introduction: To develop and test the feasibility of free-breathing (FB), high-resolution quantitative first-pass perfusion cardiac MR (FPP-CMR) using dual-echo Dixon (FOSTERS; Fat-water separation for mOtion-corrected Spatio-TEmporally accelerated myocardial peRfuSion). Materials and Methods: FOSTERS was performed in FB using a dual-saturation single-bolus acquisition with dual-echo Dixon and a dynamically variable Cartesian k-t undersampling (8-fold) approach, with low-rank and sparsity constrained reconstruction, to achieve high-resolution FPP-CMR images. FOSTERS also included automatic in-plane motion estimation and T 2 * correction to obtain quantitative myocardial blood flow (MBF) maps. High-resolution (1.6 x 1.6 mm2) FB FOSTERS was evaluated in eleven patients, during rest, against standard-resolution (2.6 x 2.6 mm2) 2-fold SENSE-accelerated breath-hold (BH) FPP-CMR. In addition, MBF was computed for FOSTERS and spatial wavelet-based compressed sensing (CS) reconstruction. Two cardiologists scored the image quality (IQ) of FOSTERS, CS, and standard BH FPP-CMR images using a 4-point scale (1-4, non-diagnostic - fully diagnostic). Results: FOSTERS produced high-quality images without dark-rim and with reduced motion-related artifacts, using an 8x accelerated FB acquisition. FOSTERS and standard BH FPP-CMR exhibited excellent IQ with an average score of 3.5 ± 0.6 and 3.4 ± 0.6 (no statistical difference, p > 0.05), respectively. CS images exhibited severe artifacts and high levels of noise, resulting in an average IQ score of 2.9 ± 0.5. MBF values obtained with FOSTERS presented a lower variance than those obtained with CS. Discussion: FOSTERS enabled high-resolution FB FPP-CMR with MBF quantification. Combining motion correction with a low-rank and sparsity-constrained reconstruction results in excellent image quality.

Deep learning methods for automatic evaluation of delayed enhancement-MRI. The results of the EMIDEC challenge.

A key factor for assessing the state of the heart after myocardial infarction (MI) is to measure whether the myocardium segment is viable after reperfusion or revascularization therapy. Delayed enhancement-MRI or DE-MRI, which is performed 10 min after injection of the contrast agent, provides high contrast between viable and nonviable myocardium and is therefore a method of choice to evaluate the extent of MI. To automatically assess myocardial status, the results of the EMIDEC challenge that focused on this task are presented in this paper. The challenge's main objectives were twofold. First, to evaluate if deep learning methods can distinguish between non-infarct and pathological exams, i.e. exams with or without hyperenhanced area. Second, to automatically calculate the extent of myocardial infarction. The publicly available database consists of 150 exams divided into 50 cases without any hyperenhanced area after injection of a contrast agent and 100 cases with myocardial infarction (and then with a hyperenhanced area on DE-MRI), whatever their inclusion in the cardiac emergency department. Along with MRI, clinical characteristics are also provided. The obtained results issued from several works show that the automatic classification of an exam is a reachable task (the best method providing an accuracy of 0.92), and the automatic segmentation of the myocardium is possible. However, the segmentation of the diseased area needs to be improved, mainly due to the small size of these areas and the lack of contrast with the surrounding structures.

Cardiac MR: From Theory to Practice.

Cardiovascular disease (CVD) is the leading single cause of morbidity and mortality, causing over 17. 9 million deaths worldwide per year with associated costs of over $800 billion. Improving prevention, diagnosis, and treatment of CVD is therefore a global priority. Cardiovascular magnetic resonance (CMR) has emerged as a clinically important technique for the assessment of cardiovascular anatomy, function, perfusion, and viability. However, diversity and complexity of imaging, reconstruction and analysis methods pose some limitations to the widespread use of CMR. Especially in view of recent developments in the field of machine learning that provide novel solutions to address existing problems, it is necessary to bridge the gap between the clinical and scientific communities. This review covers five essential aspects of CMR to provide a comprehensive overview ranging from CVDs to CMR pulse sequence design, acquisition protocols, motion handling, image reconstruction and quantitative analysis of the obtained data. (1) The basic MR physics of CMR is introduced. Basic pulse sequence building blocks that are commonly used in CMR imaging are presented. Sequences containing these building blocks are formed for parametric mapping and functional imaging techniques. Commonly perceived artifacts and potential countermeasures are discussed for these methods. (2) CMR methods for identifying CVDs are illustrated. Basic anatomy and functional processes are described to understand the cardiac pathologies and how they can be captured by CMR imaging. (3) The planning and conduct of a complete CMR exam which is targeted for the respective pathology is shown. Building blocks are illustrated to create an efficient and patient-centered workflow. Further strategies to cope with challenging patients are discussed. (4) Imaging acceleration and reconstruction techniques are presented that enable acquisition of spatial, temporal, and parametric dynamics of the cardiac cycle. The handling of respiratory and cardiac motion strategies as well as their integration into the reconstruction processes is showcased. (5) Recent advances on deep learning-based reconstructions for this purpose are summarized. Furthermore, an overview of novel deep learning image segmentation and analysis methods is provided with a focus on automatic, fast and reliable extraction of biomarkers and parameters of clinical relevance.

Prática clínica dos enfermeiros na prevenção da infeção associada ao cateter venoso central / Nurses' clinical practice for the prevention of central venous catheter-related infections / Práctica clínica de los enfermeros en la prevención de la infección asociada al catéter venoso central

Resumo Enquadramento: O presente estudo analisa uma problemática identificada na prática profissional diária de enfermagem, sendo definido o tema "Prática clínica dos enfermeiros na prevenção da infeção associada ao cateter venoso central (CVC)". Objetivos: Conhecer a prática clínica e o nível de conhecimentos dos enfermeiros sobre a manutenção do CVC. Metodologia: Estudo analítico e transversal, com uma metodologia quantitativa, utilizando um instrumento de recolha de dados aplicado em dezembro de 2018, através da técnica de amostragem por bola de neve, a 272 enfermeiros selecionados aleatoriamente. Resultados: Os resultados obtidos indicam altos níveis de prática clínica (90,1%) e de conhecimentos (85,7%) na realização do penso e na manutenção do CVC e que existe relação estatisticamente significativa entre a prática clínica e o nível de conhecimentos dos enfermeiros. Conclusão: Concluiu-se que a amostra apresenta um nível alto de conhecimentos acerca das normas de manutenção do CVC da prevenção da infeção e uma prática clínica que respeita, na sua maioria, as orientações dos feixes de intervenção acerca das práticas de prevenção da infeção do CVC.

Abstract Background: This study analyzes an issue that has already been identified in daily nursing practice, having defined the theme "Nurses' clinical practice for the prevention of central venous catheter (CVC)-related infections". Objectives: To identify nurses' clinical practice and level of knowledge about CVC maintenance. Methodology: Analytical and cross-sectional study, with a quantitative methodology. A data collection instrument was applied in December 2018, through the snowball sampling technique, to 272 randomly selected nurses. Results: The results indicated high levels of clinical practice (90.1%) and knowledge (85.7%) about CVC dressing change and CVC maintenance. A statistically significant association was also found between nurses' clinical practices and level of knowledge. Conclusion: The study concluded that the nurses have a high level of knowledge about CVC maintenance guidelines for infection prevention and that they follow the majority of the guidelines of the bundles for prevention of CVC-related infections.

Resumen Marco contextual: Este estudio analiza una problemática identificada en la práctica profesional diaria de la enfermería; el tema es Práctica clínica de los enfermeros en la prevención de la infección asociada al catéter venoso central (CVC). Objetivos: Conocer la práctica clínica y el nivel de conocimiento de los enfermeros sobre el mantenimiento del CVC. Metodología: Estudio analítico y transversal, con una metodología cuantitativa, mediante un instrumento de recogida de datos aplicado en diciembre de 2018, a través de la técnica de muestreo por bola de nieve, a 272 enfermeros seleccionados aleatoriamente. Resultados: Los resultados obtenidos indican niveles elevados de práctica clínica (90,1%) y de conocimiento (85,7%) del vendaje y del mantenimiento del CVC, y que existe una relación estadísticamente significativa entre la práctica clínica y el nivel de conocimiento de los enfermeros. Conclusión: Se concluyó que la muestra presenta un nivel alto de conocimiento sobre las normas de mantenimiento del CVC para la prevención de infecciones y una práctica clínica que respeta, en su mayoría, las directrices del paquete de intervención sobre las prácticas de prevención de infecciones del CVC.

Surgical approach to gastric polyposis in Cowen syndrome-case report.

Cowden syndrome is a rare autosomal dominant disorder that is characterized by multiple hamartomatous neoplasms in a variety of tissues and is associated with germline mutations in the PTEN gene. Cowden syndrome does not have increased risk of gastric malignancy; however, complications of benign neoplasm can occur. The authors report a case of a patient with Cowden Syndrome and with gastric polyps that caused severe morbidity and a surgical approach was indicated. An antrectomy with troncular vagotomy was performed with a Billroth I reconstruction. In this case, this was of paramount importance so the duodenum can be revisited.

Case Report: Parental Loss and Childhood Grief During COVID-19 Pandemic.

The coronavirus disease 2019 (COVID-19) pandemic is an unprecedent public health crisis, transforming many aspects of our daily life. Protection measures, such as social distancing, nationwide lockdowns, and restrictions on hospital visits and funerals have a serious impact on how people mourn their loved ones. The grieving process during childhood and adolescence evolves along the developmental stages and is a dynamic, non-linear process that needs time. Parental death increases the risk for psychopathology in the short and long term. We present a case of an 11-year-old girl referred to child psychiatry-liaison service by her neurologist due to peer relationship problems and sadness. Fifteen days before her first psychiatric consultation, her father suffered a myocardial infarction complicated with hypoxic ischemic encephalopathy, and he was hospitalized in the intensive care unit. Positive coping mechanisms and adaptive emotional expression strategies were explored during her consultations. Her father died 2 weeks after emergency state and nationwide lockdown was declared in Portugal, during the first COVID-19 outbreak. The family did not have the opportunity for a proper farewell, the funeral obeyed strict rules, and the patient and her family were at home, due to social distancing and school closure policies. Consultations were maintained by telephone calls and, less frequently, by face-to-face appointments. Adaptive and helpful strategies to grieve were shared with the patient and her mother. Intervention with the mother alone was also helpful. Death circumstances related to COVID-19, confinement policies, and social-economical stressors can intensify the grief experience, increasing the risk for complicated grief. Although psychiatric teleconsultation is essential during COVID-19 pandemic, it poses various limitations. Non-verbal communication clues may not be totally apprehended; it may represent a problem in the therapeutic relationship, and access to technology can be difficult for psychiatric patients and clinicians. COVID-19 pandemic policies should include mental health protection measures, which should facilitate adjusted grief responses for those who lose a loved one during this pandemic.

Accelerated high-resolution free-breathing 3D whole-heart T2-prepared black-blood and bright-blood cardiovascular magnetic resonance.

BACKGROUND: The free-breathing 3D whole-heart T2-prepared Bright-blood and black-blOOd phase SensiTive inversion recovery (BOOST) cardiovascular magnetic resonance (CMR) sequence was recently proposed for simultaneous bright-blood coronary CMR angiography and black-blood late gadolinium enhancement (LGE) imaging. This sequence enables simultaneous visualization of cardiac anatomy, coronary arteries and fibrosis. However, high-resolution (< 1.4 × 1.4 × 1.4 mm3) fully-sampled BOOST requires long acquisition times of ~ 20 min. METHODS: In this work, we propose to extend a highly efficient respiratory-resolved motion-corrected reconstruction framework (XD-ORCCA) to T2-prepared BOOST to enable high-resolution 3D whole-heart coronary CMR angiography and black-blood LGE in a clinically feasible scan time. Twelve healthy subjects were imaged without contrast injection (pre-contrast BOOST) and 10 patients with suspected cardiovascular disease were imaged after contrast injection (post-contrast BOOST). A quantitative analysis software was used to compare accelerated pre-contrast BOOST against the fully-sampled counterpart (vessel sharpness and length of the left and right coronary arteries). Moreover, three cardiologists performed diagnostic image quality scoring for clinical 2D LGE and both bright- and black-blood 3D BOOST imaging using a 4-point scale (1-4, non-diagnostic-fully diagnostic). A two one-sided test of equivalence (TOST) was performed to compare the pre-contrast BOOST images. Nonparametric TOST was performed to compare post-contrast BOOST image quality scores. RESULTS: The proposed method produces images from 3.8 × accelerated non-contrast-enhanced BOOST acquisitions with comparable vessel length and sharpness to those obtained from fully- sampled scans in healthy subjects. Moreover, in terms of visual grading, the 3D BOOST LGE datasets (median 4) and the clinical 2D counterpart (median 3.5) were found to be statistically equivalent (p < 0.05). In addition, bright-blood BOOST images allowed for visualization of the proximal and middle left anterior descending and right coronary sections with high diagnostic quality (mean score > 3.5). CONCLUSIONS: The proposed framework provides high-resolution 3D whole-heart BOOST images from a single free-breathing acquisition in ~ 7 min.

Strain maps of the left atrium imaged with a novel high-resolution CINE MRI protocol.

To date, regional atrial strains have not been imaged in vivo, despite their potential to provide useful clinical information. To address this gap, we present a novel CINE MRI protocol capable of imaging the entire left atrium at an isotropic 2-mm resolution in one single breath-hold. As proof of principle, we acquired data in 10 healthy volunteers and 2 cardiovascular patients using this technique. We also demonstrated how regional atrial strains can be estimated from this data following a manual segmentation of the left atrium using automatic image tracking techniques. The estimated principal strains vary smoothly across the left atrium and have a similar magnitude to estimates reported in the literature.

SINAS: Effective Impact in the Quality Improvement of Ambulatory Surgery at an Ambulatory Centre.

INTRODUCTION: The National Health Assessment System is a system designed by the Portuguese Health Regulatory Entity in order to evaluate the overall quality of the health care institutions. One of the key areas evaluated by the National Health Assessment System is ambulatory surgery. The aim of this study is to demonstrate that the introduction of the National Health Assessment System evaluation at our ambulatory centre not only improved the overall quality of ambulatory surgery but also the quality of the clinical record entries. MATERIAL AND METHODS: A retrospective analysis was performed from the hospital's clinical database. The study was carried out at the ambulatory centre of the Hospital and University Centre of Porto, and included 100 consecutive surgical procedures, across all surgical specialties, previously selected by the National Health Assessment System audit performed in 2015 in our ambulatory surgery centre and other 46 surgical procedures performed in 2008 at our hospital, before the National Health Assessment System was implemented. The main outcome measure was the validation and record of the seven indicators of National Health Assessment System for ambulatory surgery. RESULTS: We have seen an improvement in all indicators after the National Health Assessment System implementation, except for criterion 4. DISCUSSION: Our study demonstrates that the introduction of the National Health Assessment System in our ambulatory centre resulted in the improvement in the quality of both of clinical practice, and clinical record keepingConclusion: We can conclude that the application of evaluation of quality indicators and benchmarking practices can be used to enhance healthcare outcomes.

Introdução: O Sistema Nacional de Avaliação da Saúde é um sistema de avaliação da qualidade global dos prestadores de cuidados de saúde desenvolvido pela Entidade Reguladora da Saúde. Uma das áreas avaliadas pelo Sistema Nacional de Avaliação da Saúde é a cirurgia de ambulatório. O objetivo do nosso trabalho é demonstrar que a introdução da avaliação do Sistema Nacional de Avaliação da Saúde no nosso hospital melhorou não só a qualidade da cirurgia de ambulatório, mas também a qualidade do registo clinico. Material e Métodos: Estudo retrospectivo dos dados clínicos do hospital. O estudo foi realizado no centro integrado de cirurgia de ambulatório do Centro Hospitalar e Universitário do Porto. Foram analisados 100 procedimentos cirúrgicos consecutivos, de todas as especialidades cirúrgicas, previamente selecionados para a auditoria Sinas, realizada no ano de 2015 e 46 procedimentos cirúrgicos realizados em 2008 no nosso hospital, antes da implantação do Sistema Nacional de Avaliação da Saúde. Foi avaliada a validação e registo dos sete indicadores do Sistema Nacional de Avaliação da Saúde para cirurgia de ambulatório. Resultados: Verificou-se uma melhoria em todos os indicadores após a implementação do Sistema Nacional de Avaliação da Saúde, exceto para o indicador 4. Discussão: O nosso trabalho demonstra que a introdução do Sistema Nacional de Avaliação da Saúde no nosso centro de ambulatório resulta na melhoria não apenas das práticas clínicas, mas também dos registros clínicos. Conclusão: Concluímos assim que a aplicação de avaliação de indicadores de qualidade e benchmarking pode ser usada para melhorar os resultados de saúde.

Feasibility of free-breathing quantitative myocardial perfusion using multi-echo Dixon magnetic resonance imaging.

Dynamic contrast-enhanced quantitative first-pass perfusion using magnetic resonance imaging enables non-invasive objective assessment of myocardial ischemia without ionizing radiation. However, quantification of perfusion is challenging due to the non-linearity between the magnetic resonance signal intensity and contrast agent concentration. Furthermore, respiratory motion during data acquisition precludes quantification of perfusion. While motion correction techniques have been proposed, they have been hampered by the challenge of accounting for dramatic contrast changes during the bolus and long execution times. In this work we investigate the use of a novel free-breathing multi-echo Dixon technique for quantitative myocardial perfusion. The Dixon fat images, unaffected by the dynamic contrast-enhancement, are used to efficiently estimate rigid-body respiratory motion and the computed transformations are applied to the corresponding diagnostic water images. This is followed by a second non-linear correction step using the Dixon water images to remove residual motion. The proposed Dixon motion correction technique was compared to the state-of-the-art technique (spatiotemporal based registration). We demonstrate that the proposed method performs comparably to the state-of-the-art but is significantly faster to execute. Furthermore, the proposed technique can be used to correct for the decay of signal due to T2* effects to improve quantification and additionally, yields fat-free diagnostic images.

3D whole-heart isotropic sub-millimeter resolution coronary magnetic resonance angiography with non-rigid motion-compensated PROST.

BACKGROUND: To enable free-breathing whole-heart sub-millimeter resolution coronary magnetic resonance angiography (CMRA) in a clinically feasible scan time by combining low-rank patch-based undersampled reconstruction (3D-PROST) with a highly accelerated non-rigid motion correction framework. METHODS: Non-rigid motion corrected CMRA combined with 2D image-based navigators has been previously proposed to enable 100% respiratory scan efficiency in modestly undersampled acquisitions. Achieving sub-millimeter isotropic resolution with such techniques still requires prohibitively long acquisition times. We propose to combine 3D-PROST reconstruction with a highly accelerated non-rigid motion correction framework to achieve sub-millimeter resolution CMRA in less than 10 min. Ten healthy subjects and eight patients with suspected coronary artery disease underwent 4-5-fold accelerated free-breathing whole-heart CMRA with 0.9 mm3 isotropic resolution. Vessel sharpness, vessel length and image quality obtained with the proposed non-rigid (NR) PROST approach were compared against translational correction only (TC-PROST) and a previously proposed NR motion-compensated technique (non-rigid SENSE) in healthy subjects. For the patient study, image quality scoring and visual comparison with coronary computed tomography angiography (CCTA) were performed. RESULTS: Average scan times [min:s] were 6:01 ± 0:59 (healthy subjects) and 8:29 ± 1:41 (patients). In healthy subjects, vessel sharpness of the left anterior descending (LAD) and right (RCA) coronary arteries were improved with the proposed non-rigid PROST (LAD: 51.2 ± 8.8%, RCA: 61.2 ± 9.1%) in comparison to TC-PROST (LAD: 43.8 ± 5.1%, P = 0.051, RCA: 54.3 ± 8.3%, P = 0.218) and non-rigid SENSE (LAD: 46.1 ± 5.8%, P = 0.223, RCA: 56.7 ± 9.6%, P = 0.50), although differences were not statistically significant. The average visual image quality score was significantly higher for NR-PROST (LAD: 3.2 ± 0.6, RCA: 3.3 ± 0.7) compared with TC-PROST (LAD: 2.1 ± 0.6, P = 0.018, RCA: 2.0 ± 0.7, P = 0.014) and non-rigid SENSE (LAD: 2.3 ± 0.5, P = 0.008, RCA: 2.5 ± 0.7, P = 0.016). In patients, the proposed approach showed good delineation of the coronaries, in agreement with CCTA, with image quality scores and vessel sharpness similar to that of healthy subjects. CONCLUSIONS: We demonstrate the feasibility of combining high undersampling factors with non-rigid motion-compensated reconstruction to obtain high-quality sub-millimeter isotropic CMRA images in ~ 8 min. Validation in a larger cohort of patients with coronary artery disease is now warranted.