1,256 research outputs found
New imaging signatures of cardiac alterations in ischaemic heart disease and cerebrovascular disease using CMR radiomics
Background: Ischaemic heart disease (IHD) and cerebrovascular disease are two closely inter-related clinical entities. Cardiovascular magnetic resonance (CMR) radiomics may capture subtle cardiac changes associated with these two diseases providing new insights into the brain-heart interactions.Objective: To define the CMR radiomics signatures for IHD and cerebrovascular disease and study their incremental value for disease discrimination over conventional CMR indices.Methods: We analysed CMR images of UK Biobank's subjects with pre-existing IHD, ischaemic cerebrovascular disease, myocardial infarction (MI), and ischaemic stroke (IS) (n = 779, 267, 525, and 107, respectively). Each disease group was compared with an equal number of healthy controls. We extracted 446 shape, first-order, and texture radiomics features from three regions of interest (right ventricle, left ventricle, and left ventricular myocardium) in end-diastole and end-systole defined from segmentation of short-axis cine images. Systematic feature selection combined with machine learning (ML) algorithms (support vector machine and random forest) and 10-fold cross-validation tests were used to build the radiomics signature for each condition. We compared the discriminatory power achieved by the radiomics signature with conventional indices for each disease group, using the area under the curve (AUC), receiver operating characteristic (ROC) analysis, and paired t-test for statistical significance. A third model combining both radiomics and conventional indices was also evaluated.Results: In all the study groups, radiomics signatures provided a significantly better disease discrimination than conventional indices, as suggested by AUC (IHD:0.82 vs. 0.75; cerebrovascular disease: 0.79 vs. 0.77; MI: 0.87 vs. 0.79, and IS: 0.81 vs. 0.72). Similar results were observed with the combined models. In IHD and MI, LV shape radiomics were dominant. However, in IS and cerebrovascular disease, the combination of shape and intensity-based features improved the disease discrimination. A notable overlap of the radiomics signatures of IHD and cerebrovascular disease was also found.Conclusions: This study demonstrates the potential value of CMR radiomics over conventional indices in detecting subtle cardiac changes associated with chronic ischaemic processes involving the brain and heart, even in the presence of more heterogeneous clinical pictures. Radiomics analysis might also improve our understanding of the complex mechanisms behind the brain-heart interactions during ischaemia
Current and Future Role of Artificial Intelligence in Cardiac Imaging
Cardiovascular disease remains the most common cause of morbidity and mortality worldwide, and thus an important focus for medical research and medical imaging. Despite continuous advances in cardiac imaging modalities, including echocardiography, cardiovascular magnetic resonance and cardiac computed tomography, the heart remains a challenging organ to image, in particular due to its perpetual motion. Other challenges faced by cardiac imaging include respiratory motion, complex geometry of the ventricles and atria, variability in imaging conditions and protocols, oblique orientation of the heart with respect to the body, and the small size of some of the cardiac structures, including the coronary arteries, trabeculae and papillary muscles
its goals, rationale, data infrastructure, and current developments
Background With multifaceted imaging capabilities, cardiovascular magnetic
resonance (CMR) is playing a progressively increasing role in the management
of various cardiac conditions. A global registry that harmonizes data from
international centers, with participation policies that aim to be open and
inclusive of all CMR programs, can support future evidence-based growth in
CMR. Methods The Global CMR Registry (GCMR) was established in 2013 under the
auspices of the Society for Cardiovascular Magnetic Resonance (SCMR). The GCMR
team has developed a web-based data infrastructure, data use policy and
participation agreement, data-harmonizing methods, and site-training tools
based on results from an international survey of CMR programs. Results At
present, 17 CMR programs have established a legal agreement to participate in
GCMR, amongst them 10 have contributed CMR data, totaling 62,456 studies.
There is currently a predominance of CMR centers with more than 10 years of
experience (65%), and the majority are located in the United States (63%). The
most common clinical indications for CMR have included assessment of
cardiomyopathy (21%), myocardial viability (16%), stress CMR perfusion for
chest pain syndromes (16%), and evaluation of etiology of arrhythmias or
planning of electrophysiological studies (15%) with assessment of
cardiomyopathy representing the most rapidly growing indication in the past
decade. Most CMR studies involved the use of gadolinium-based contrast media
(95%). Conclusions We present the goals, mission and vision, infrastructure,
preliminary results, and challenges of the GCMR. Trial registration
Identification number on ClinicalTrials.gov: NCT02806193. Registered 17 June
2016
The natural time course of myocardial oedema in the 12 months post ST-elevation MI in patients treated with primary angioplasty
A radiomics approach to analyze cardiac alterations in hypertension
Hypertension is a medical condition that is well-established as a risk factor
for many major diseases. For example, it can cause alterations in the cardiac
structure and function over time that can lead to heart related morbidity and
mortality. However, at the subclinical stage, these changes are subtle and
cannot be easily captured using conventional cardiovascular indices calculated
from clinical cardiac imaging. In this paper, we describe a radiomics approach
for identifying intermediate imaging phenotypes associated with hypertension.
The method combines feature selection and machine learning techniques to
identify the most subtle as well as complex structural and tissue changes in
hypertensive subgroups as compared to healthy individuals. Validation based on
a sample of asymptomatic hearts that include both hypertensive and
non-hypertensive cases demonstrate that the proposed radiomics model is capable
of detecting intensity and textural changes well beyond the capabilities of
conventional imaging phenotypes, indicating its potential for improved
understanding of the longitudinal effects of hypertension on cardiovascular
health and disease
Stress myocardial perfusion cardiac magnetic resonance imaging vs. coronary CT angiography in the diagnostic work-up of patients with stable chest pain: comparative effectiveness and costs
The Relationship of Left Ventricular Trabeculation to Ventricular Function and Structure Over a 9.5-Year Follow-Up The MESA Study
Left ventricular (LV) trabeculation is highly variable among individuals and is increased in some diseases (e.g., congenital heart disease or cardiomyopathies), but its significance in population-representative individuals is unknown
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