157 research outputs found
The Role of Cardiovascular Magnetic Resonance in Congenital Heart Disease
The increasing prevalence of congenital heart disease (CHD) can be attributed to major improvements in diagnosis and treatment. Although echocardiography is the most commonly used imaging modality for diagnosis and follow up of subjects with CHD, the evolution of both cardiovascular magnetic resonance (MR) imaging and computed tomography (CT) does offer new ways to visualize the heart and the great vessels. The development of cardiovascular MR techniques such as spinecho and gradient-echo imaging, velocity-encoded phase contrast MR and gadolinium-enhanced MR angiography allow comprehensive assessment of cardiac anatomy and function. This provides information about the long-term sequelae of the underlying complex anatomy, hemodynamic assessment of residual post-operative lesions and complications of surgery. As much of the functional data in CHD patients is usually acquired with invasive X-ray angiography, non-invasive alternatives such as cardiovascular MR and CT are desirable. This review evaluates the role of both these modalities in the management of subjects with CHD, particularly detailing recent developments in imaging techniques as they relate to the various CHD diagnoses we commonly encounter in our practice
Real-time Assessment of Right and Left Ventricular Volumes and Function in Children Using High Spatiotemporal Resolution Spiral bSSFP with Compressed Sensing
Background: Real-time (RT) assessment of ventricular volumes and function
enables data acquisition during free-breathing. However, in children the
requirement for high spatiotemporal resolution requires accelerated imaging
techniques. In this study, we implemented a novel RT bSSFP spiral sequence
reconstructed using Compressed Sensing (CS) and validated it against the
breath-hold (BH) reference standard for assessment of ventricular volumes in
children with heart disease.
Methods: Data was acquired in 60 children. Qualitative image scoring and
evaluation of ventricular volumes was performed by 3 clinical cardiac MR
specialists. 30 cases were reassessed for intra-observer variability, and the
other 30 cases for inter-observer variability.
Results: Spiral RT images were of good quality, however qualitative scores
reflected more residual artefact than standard BH images and slightly lower
edge definition. Quantification of Left Ventricular (LV) and Right Ventricular
(RV) metrics showed excellent correlation between the techniques with narrow
limits of agreement. However, we observed small but statistically significant
overestimation of LV end-diastolic volume, underestimation of LV end-systolic
volume, as well as a small overestimation of RV stroke volume and ejection
fraction using the RT imaging technique. No difference in inter-observer or
intra-observer variability were observed between the BH and RT sequences.
Conclusions: Real-time bSSFP imaging using spiral trajectories combined with
a compressed sensing reconstruction is feasible. The main benefit is that it
can be acquired during free breathing. However, another important secondary
benefit is that a whole ventricular stack can be acquired in ~20 seconds, as
opposed to ~6 minutes for standard BH imaging. Thus, this technique holds the
potential to significantly shorten MR scan times in children
The role of artificial intelligence in healthcare: a structured literature review
BACKGROUND/INTRODUCTION: Artificial intelligence (AI) in the healthcare sector is receiving attention from researchers and health professionals. Few previous studies have investigated this topic from a multi-disciplinary perspective, including accounting, business and management, decision sciences and health professions. METHODS: The structured literature review with its reliable and replicable research protocol allowed the researchers to extract 288 peer-reviewed papers from Scopus. The authors used qualitative and quantitative variables to analyse authors, journals, keywords, and collaboration networks among researchers. Additionally, the paper benefited from the Bibliometrix R software package. RESULTS: The investigation showed that the literature in this field is emerging. It focuses on health services management, predictive medicine, patient data and diagnostics, and clinical decision-making. The United States, China, and the United Kingdom contributed the highest number of studies. Keyword analysis revealed that AI can support physicians in making a diagnosis, predicting the spread of diseases and customising treatment paths. CONCLUSIONS: The literature reveals several AI applications for health services and a stream of research that has not fully been covered. For instance, AI projects require skills and data quality awareness for data-intensive analysis and knowledge-based management. Insights can help researchers and health professionals understand and address future research on AI in the healthcare field
The aorta after coarctation repair : effects of calibre and curvature on arterial haemodynamics (vol 21, 22, 2019)
In the original version of this article [1], published on 11 April 2019, there is 1 error in the Conclusion' paragraph of the abstract
Real-time Cardiovascular MR with Spatio-temporal Artifact Suppression using Deep Learning - Proof of Concept in Congenital Heart Disease
PURPOSE: Real-time assessment of ventricular volumes requires high
acceleration factors. Residual convolutional neural networks (CNN) have shown
potential for removing artifacts caused by data undersampling. In this study we
investigated the effect of different radial sampling patterns on the accuracy
of a CNN. We also acquired actual real-time undersampled radial data in
patients with congenital heart disease (CHD), and compare CNN reconstruction to
Compressed Sensing (CS).
METHODS: A 3D (2D plus time) CNN architecture was developed, and trained
using 2276 gold-standard paired 3D data sets, with 14x radial undersampling.
Four sampling schemes were tested, using 169 previously unseen 3D 'synthetic'
test data sets. Actual real-time tiny Golden Angle (tGA) radial SSFP data was
acquired in 10 new patients (122 3D data sets), and reconstructed using the 3D
CNN as well as a CS algorithm; GRASP.
RESULTS: Sampling pattern was shown to be important for image quality, and
accurate visualisation of cardiac structures. For actual real-time data,
overall reconstruction time with CNN (including creation of aliased images) was
shown to be more than 5x faster than GRASP. Additionally, CNN image quality and
accuracy of biventricular volumes was observed to be superior to GRASP for the
same raw data.
CONCLUSION: This paper has demonstrated the potential for the use of a 3D CNN
for deep de-aliasing of real-time radial data, within the clinical setting.
Clinical measures of ventricular volumes using real-time data with CNN
reconstruction are not statistically significantly different from the
gold-standard, cardiac gated, BH techniques
Abnormal wave reflections and left ventricular hypertrophy late after coarctation of the aorta repair
Patients with repaired coarctation of the aorta are thought to have increased afterload due to abnormalities in vessel structure and function. We have developed a novel cardiovascular magnetic resonance protocol that allows assessment of central hemodynamics, including central aortic systolic blood pressure, resistance, total arterial compliance, pulse wave velocity, and wave reflections. The main study aims were to (1) characterize group differences in central aortic systolic blood pressure and peripheral systolic blood pressure, (2) comprehensively evaluate afterload (including wave reflections) in the 2 groups, and (3) identify possible biomarkers among covariates associated with elevated left ventricular mass (LVM). Fifty adult patients with repaired coarctation and 25 age- and sex-matched controls were recruited. Ascending aorta area and flow waveforms were obtained using a high temporal-resolution spiral phase-contrast cardiovascular magnetic resonance flow sequence. These data were used to derive central hemodynamics and to perform wave intensity analysis noninvasively. Covariates associated with LVM were assessed using multivariable linear regression analysis. There were no significant group differences (P≥0.1) in brachial systolic, mean, or diastolic BP. However central aortic systolic blood pressure was significantly higher in patients compared with controls (113 versus 107 mm Hg, P=0.002). Patients had reduced total arterial compliance, increased pulse wave velocity, and larger backward compression waves compared with controls. LVM index was significantly higher in patients than controls (72 versus 59 g/m(2), P<0.0005). The magnitude of the backward compression waves was independently associated with variation in LVM (P=0.01). Using a novel, noninvasive hemodynamic assessment, we have shown abnormal conduit vessel function after coarctation of the aorta repair, including abnormal wave reflections that are associated with elevated LVM
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