Detection of Left Ventricular Cavity from Cardiac MRI Images Using Faster R-CNN

The automatic localization of the left ventricle(LV)in short-axis magnetic resonance(MR)images is a required step to process cardiac images using convolutional neural networks for the extraction of a region of interest(ROI).The precise extraction of the LV’s ROI from cardiac MRI images is crucial for detecting heart disorders via cardiac segmentation or registration.Nevertheless,this task appears to be intricate due to the diversities in the size and shape of the LV and the scattering of surrounding tissues across different slices.Thus,this study proposed a region-based convolutional network(Faster R-CNN)for the LV localization from short-axis cardiac MRI images using a region proposal network(RPN)integrated with deep feature classification and regression.Themodel was trained using images with corresponding bounding boxes(labels)around the LV,and various experiments were applied to select the appropriate layers and set the suitable hyper-parameters.The experimental findings showthat the proposed modelwas adequate,with accuracy,precision,recall,and F1 score values of 0.91,0.94,0.95,and 0.95,respectively.This model also allows the cropping of the detected area of LV,which is vital in reducing the computational cost and time during segmentation and classification procedures.Therefore,itwould be an ideal model and clinically applicable for diagnosing cardiac diseases.

Tricuspid mass-curious case of Li-Fraumeni syndrome: A case report

BACKGROUND Li-Fraumeni syndrome(LFS)is a rare autosomal dominant cancer-predisposing syndrome,which can manifest as a polymorphic spectrum of malignancies.LFS is associated with an early onset in life,with the majority of cases occurring prior to the age of 46.Notwithstanding the infrequency of primary cardiac tumors,it behooves clinicians to remain vigilant in considering the differential diagnosis of such tumors in LFS patients who present with a cardiac mass.This is due to the markedly elevated risk for malignancy in this particular population,far surpassing that of the general populace.CASE SUMMARY Herein,we present a case of a 30-year-old female with LFS who was found to have a tricuspid valve leaflet mass.CONCLUSION This case exemplifies valuable learning points in the diagnostic approach for this exceptionally rare patient population.

Cardiac magnetic source imaging based on current multipole model

It is widely accepted that the heart current source can be reduced into a current multipole. By adopting three linear inverse methods, the cardiac magnetic imaging is achieved in this article based on the current multipole model expanded to the first order terms. This magnetic imaging is realized in a reconstruction plane in the centre of human heart, where the current dipole array is employed to represent realistic cardiac current distribution. The current multipole as testing source generates magnetic fields in the measuring plane, serving as inputs of cardiac magnetic inverse problem. In the heart-torso model constructed by boundary element method, the current multipole magnetic field distribution is compared with that in the homogeneous infinite space, and also with the single current dipole magnetic field distribution. Then the minimum-norm least-squares （MNLS） method, the optimal weighted pseudoinverse method （OWPIM）, and the optimal constrained linear inverse method （OCLIM） are selected as the algorithms for inverse computation based on current multipole model innovatively, and the imaging effects of these three inverse methods are compared. Besides, two reconstructing parameters, residual and mean residual, are also discussed, and their trends under MNLS, OWPIM and OCLIM each as a function of SNR are obtained and compared.

Forward and inverse problem for cardiac magnetic field and electric potential using two boundary element methods

This paper discusses the forward and inverse problem for cardiac magnetic fields and electric potentials. A torso-heart model established by boundary element method （BEM） is used for studying the distributions of cardiac magnetic fields and electric potentials. Because node-to-node and triangle-to-triangle BEM can lead to discrepant field distributions, their properties and influences are compared. Then based on constructed torso-heart model and supposed current source functional model-current dipole array, the magnetic and electric imaging by optimal constrained linear inverse method are applied at the same time. Through figure and reconstructing parameter comparison, though the magnetic current dipole array imaging possesses better reconstructing effect, however node-to-node BEM and triangleto-triangle BEM make little difference to magnetic and electric imaging.

Multi-modality imaging of cardiac amyloidosis: Contemporary update

Cardiac amyloidosis is a heterogeneous and challenging diagnostic disease with poor prognosis that is now being altered by introduction of new therapies.Echocardiography remains the first-line imaging tool, and when disease is suspected on echocardiography, cardiac magnetic resonance imaging and nuclear imaging play critical roles in the non-invasive diagnosis and evaluation of cardiac amyloidosis. Advances in multi-modality cardiac imaging allowing earlier diagnosis and initiation of novel therapies have significantly improved the outcomes in these patients. Cardiac imaging also plays important roles in the risk stratification of patients presenting with cardiac amyloidosis. In the current review, we provide a clinical and imaging focused update, and importantly outline the imaging protocols, diagnostic and prognostic utility of multimodality cardiac imaging in the assessment of cardiac amyloidosis.

Diagnostic and prognostic value of cardiac imaging in amyloidosis

Amyloidosis is an infiltrative disease caused by extracellular protein deposition that has accumulated a lot of scientific production in recent years.Different types of amyloidosis can affect the heart.Transthyretin amyloidosis and light chain amyloidosis are the two most common types of cardiac amyloidosis.These entities have a poor prognosis,so accurate diagnostic techniques are imperative for determining an early therapeutic approach.Recent advances in cardiac imaging and diagnostic strategies show that these tools are safe and can avoid the use of invasive diagnostic techniques to histological confirmation,such as endomyocardial biopsy.We performed a review on the diagnostic and prognostic implications of different cardiac imaging techniques in cardiac amyloidosis.We mainly focus on reviewing echocardiography,cardiac magnetic resonance,computed tomography and nuclear imaging techniques and the different safety measurements that can be done with each of them.

Role of cardiac magnetic resonance imaging in the diagnosis and management of COVID-19 related myocarditis: Clinical and imaging considerations

There is a growing evidence of cardiovascular complications in coronavirusdisease 2019 (COVID-19) patients. As evidence accumulated of COVID-19 mediatedinflammatory effects on the myocardium, substantial attention has beendirected towards cardiovascular imaging modalities that facilitate this diagnosis.Cardiac magnetic resonance imaging (CMRI) is the gold standard for thedetection of structural and functional myocardial alterations and its role inidentifying patients with COVID-19 mediated cardiac injury is growing. Despiteits utility in the diagnosis of myocardial injury in this population, CMRI’s impacton patient management is still evolving. This review provides a framework for theuse of CMRI in diagnosis and management of COVID-19 patients from theperspective of a cardiologist. We review the role of CMRI in the management ofboth the acutely and remotely COVID-19 infected patient. We discuss patientselection for this imaging modality;T1, T2, and late gadolinium enhancementimaging techniques;and previously described CMRI findings in other cardiomyopathieswith potential implications in COVID-19 recovered patients.

Pursuing meaningful end-points for stem cell therapy assessment in ischemic cardiac disease

Despite optimal interventional and medical therapy, ischemic heart disease is still an important cause of morbidity and mortality worldwide. Although not included in standard of care rehabilitation, stem cell therapy(SCT) could be a solution for prompting cardiac regeneration. Multiple studies have been published from the beginning of SCT until now, but overall no unanimous conclusion could be drawn in part due to the lack of appropriate endpoints. In order to appreciate the impact of SCT, multiple markers from different categories should be considered: Structural, biological, functional, physiological, but also major adverse cardiac events or quality of life. Imaging end-points are among the most used-especially left ventricle ejection fraction(LVEF) measured through different methods. Other imaging parameters are infarct size, myocardial viability and perfusion. The impact of SCT on all of the aforementioned end-points is controversial and debatable. 2 D-echocardiography is widely exploited, but new approaches such as tissue Doppler, strain/strain rate or 3 D-echocardiography are more accurate, especially since the latter one is comparable with the MRI gold standard estimation of LVEF. Apart from the objective parameters, there are also patient-centered evaluations to reveal the benefits of SCT, such as quality of life and performance status, the most valuable from the patient point of view. Emerging parameters investigating molecular pathways such as non-coding RNAs or inflammation cytokines have a high potential as prognostic factors. Due to the disadvantages of current techniques, new imaging methods with labelled cells tracked along their lifetime seem promising, but until now only pre-clinical trials have been conducted in humans. Overall, SCT is characterized by high heterogeneity not only in preparation, administration and type of cells, but also in quantification of therapy effects.

Cardiac hybrid imaging: novel tracers for novel targets

Non-invasive cardiac imaging has explored enormous advances in the last few decades.In particular,hybrid imaging represents the fusion of information from multiple imaging modalities,allowing to provide a more comprehensive dataset compared to traditional imaging techniques in patients with cardiovascular diseases.The complementary anatomical,functional and molecular information provided by hybrid systems are able to simplify the evaluation procedure of various pathologies in a routine clinical setting.The diagnostic capability of hybrid imaging modalities can be further enhanced by introducing novel and specific imaging biomarkers.The aim of this review is to cover the most recent advancements in radiotracers development for SPECT/CT,PET/CT,and PET/MRI for cardiovascular diseases.

Expanding utility of cardiac computed tomography in infective endocarditis: A contemporary review

There is increasing evidence on the utility of cardiac computed tomography(CCT)in infective endocarditis(IE)to investigate the valvular pathology,the extracardiac manifestations of IE and pre-operative planning.CCT can assist in the diagnosis of perivalvular complications,such as pseudoaneurysms and abscesses,and can help identify embolic events to the lungs or systemic vasculature.CCT has also been shown to be beneficial in the pre-operative planning of patients by delineating the coronary artery anatomy and the major cardiovascular structures in relation to the sternum.Finally,hybrid nuclear/computed tomography techniques have been shown to increase the diagnostic accuracy in prosthetic valve endocarditis.This manuscript aims to provide a contemporary update of the existing evidence base for the use of CCT in IE.

Cardiac involvement in hydrocarbon inhalant toxicity--role of cardiac magnetic resonance imaging:A case report

BACKGROUND We report a patient who was diagnosed with toxic myopericarditis secondary to hydrocarbon abuse using cardiac magnetic resonance imaging(CMR).CASE SUMMARY A 25-year-old male presented to emergency department with chest pain for 3 d.Patient also reported sniffing hydrocarbon containing inhalant for the last 1 year.Labs showed elevated troponin and electrocardiography was suggestive of acute pericarditis.Echocardiogram showed left ventricular(LV)ejection fraction(EF)of 40%.Given patient’s troponin elevation and reduced EF,cardiac catheterization was performed which showed normal coronaries.CMR was performed for myocardial infarction with non-obstructive coronary arteries evaluation.CMR showed borderline LV function with edema in mid and apical LV suggestive of myocarditis.CONCLUSION CMR can be used to diagnose toxic myopericarditis secondary to hydrocarbon abuse.

Role of cardiac magnetic resonance imaging in troponinemia syndromes

Cardiac magnetic resonance imaging(MRI)is an evolving technology,proving to be a highly accurate tool for quantitative assessment.Most recently,it has been increasingly used in the diagnostic and prognostic evaluation of conditions involving an elevation in troponin or troponinemia.Although an elevation in troponin is a nonspecific marker of myocardial tissue damage,it is a frequently ordered investigation leaving many patients without a specific diagnosis.Fortunately,the advent of newer cardiac MRI protocols can provide additional information.In this review,we discuss several conditions associated with an elevation in troponin such as myocardial infarction,myocarditis,Takotsubo cardiomyopathy,coronavirus disease 2019 related cardiac dysfunction and athlete’s heart syndrome.

Correlation between myocardial infarction activity assessed by cardiac magnetic resonance imaging and the evolution of cardiac function after PCI

Objective:To investigate the correlation of cardiac magnetic resonance imaging(MRI)in the assessment of myocardial activity in patients with myocardial infarction and the outcome of cardiac function after PCI.Methods:30 patients with myocardial infarction(MI)who had complete clinical and imaging data from July 2016 to December 2018 after PCI were analyzed retrospectively.MR and echocardiogram were performed before and 6 months after PCI,and the parameters related to left ventricular function were measured by post-processing software of MRI workstation.The left ventricular transmural degree of CMR late gadolinium enhancement was compared with the left ventricular wall motion degree of 6-month echocardiography as a standard to judge the viable myocardium.Result:There were 193 left ventricular segmental abnormalities in 30 cases,including 121 viable myocardium and 72 non viable myocardium in CMR-LGE before operation.Six months after PCI,echocardiography showed that 125 of 193 abnormal segments of left ventricle detected by CMR-LGE before PCI were viable myocardium and 68 were non viable myocaridium.The sensitivity and specificity of CMR-LGE to determinate of viable myocardium were 92.0%and 91.1%respectively.The larger the non-viable myocardial area of the left ventricular wall,the worse the recovery of wall motion ability,and there was a negative correlation between them(r=0.416,P<0.05).The first-pass perfusion time in CMR-LEG region was significantly longer than that in normal myocardial region(4.85(+)1.51)s and(3.79(+)1.73)s,respectively.The difference was statistically significant(t=5.191,P<0.05).Conclusion:MRI can evaluate the myocardial activity of myocardial infarction,reflect the range of viable myocardium,and provide imaging basis for clinical treatment and prognosis.

Biventricular isolated apical hypoplasia:First-time description of a new cardiac abnormality by multimodality imaging

Left ventricular isolated hypoplasia is a seldom-described cardiac abnormality.Right ventricular hypoplasia is usually associated with congenital anomalies of the pulmonary or the tricuspid valve,whereas biventricular isolated apical hypoplasia has never been described.We report the case of a 48-year-old man with no history of known cardiac disease who was found to have a complex cardiac abnormality characterized by:1)Deficiency of the myocardium within the biventricular apex with adipose tissue infiltration;2)Truncated right ventricle because of an absent trabecular portion of the inflow tract;3)Truncated and spherical left ventricular apex;4)Origin of the mitral papillary muscle in the flattened anterior left ventricular apex.Multimodality imaging was performed to delineate the morphological and functional characteristics of this cardiomyopathy fully.To the best of our knowledge,this is the first description of a new cardiac abnormality characterized by the hypoplasia of the apical region of both ventricles in the absence of valvular or coronary artery disease.

Role of artificial intelligence in cardiology

Artificial intelligence(AI)is the process of having a computational program that can perform tasks of human intelligence by mimicking human thought processes.AI is a rapidly evolving transdisciplinary field which integrates many elements to develop algorithms that aim to simulate human intuition,decision-making,and object recognition.The overarching aims of AI in cardiovascular medicine are threefold:To optimize patient care,improve efficiency,and improve clinical outcomes.In cardiology,there has been a growth in the potential sources of new patient data,as well as advances in investigations and therapies,which position the field well to uniquely benefit from AI.In this editorial,we highlight some of the main research priorities currently and where the next steps are heading us.

Ventricular Septal Crypts:Remnants of Spontaneous Interventricular Defect Closure?

Background:Ventricular crypts are quite a common finding during cardiac imaging,but their etiology is unclear.A possible final result of a spontaneous ventricular septal defect closure has been supposed but never investigated in earlier studies.Method:From January 1997 to December 2020,all newborns diagnosed to have a ventricular septal defect were prospectively entered in our database and those with an isolated defect were included in the study.Ventricular septal defects were classified into four types:perimembranous,trabecular muscular,inlet and outlet.A long-term follow up was performed in order to visualize the possible residual formation of a septal myocardial crypt.Results:A total of 376 isolated ventricular septal defects(314 muscular and 54 perimembranous,4 inlet,4 outlet)were detected.Follow up ranged from 1 to 23 years and showed that,among muscular type,a spontaneous closure occurred in 284(91%),26 did not close(8,28%),2 required surgical intervention(0,63%),3 were lost at follow up(0,95%).During this period,after spontaneous defect closure closure,20 crypts were found(6,4%).Conclusion:This study shows that a muscular ventricular septal defect may evolve in the 6.4%of cases in a residual septal crypt.Although septal crypts occur more frequently in patients affected by hypertrophic and hypertensive cardiomyopathy,they may also represent the evolution of a spontaneous closure of a muscular interventricular defect.

Value of clinical applications of differential pressure and relative pressure imaging in the left ventricle

Regional pressure differences between sites within the left ventricular cavity have long been identified,and the potential clinical value of diastolic and systolic intraventricular pressure differences(IVPDs)is of increasing interest.This study concluded that the IVPD plays an important role in ventricular filling and emptying and is a reliable indicator of ventricular relaxation,elastic recoil,diastolic pumping,and effective left ventricular filling.Relative pressure imaging,as a novel and potentially clinically applicable measure of left IVPDs,enables early and more comprehensive identification of the temporal and spatial characteristics of IVPD.In the future,as research related to relative pressure imaging continues,this measurement method has the possibility to become more refined and serve as an additional clinical aid that can replace the gold standard cardiac catheterization technique for the diagnosis of diastolic dysfunction.

Congenital Absence of Pericardium:The Largest Systematic Review in the Field on 247 Worldwide Cases(1977-Now)

Background:Congenital absence of pericardium(CAP),also known as pericardial agenesis,represents an uncommon cardiac abnormality and mostly incidental finding.It can be subdivided into complete and partial(left or right-sided)forms.Because of its infrequency,just case reports and a few case series have been released so far.This paper represents the largest systematic review in the field.Nine features(age at diagnosis,type,gender,clinical presentation,electrocardiography,imaging(ultrasounds,CT/MRI),concomitant cardiac defects,and outcome)were analysed.Methods:The electronic database PubMed was investigated from its establishment up to July 15th,2023.Just case reports and case series were included.Animal studies,papers that were not in English,Spanish,and Italian,and those manuscripts not reporting at least seven of the nine analysed features.were ruled out.The analysed data were reported mostly in terms of percentage.Results:One hundred eighty studies were included encompassing 247 patients.More than half of reviewed CAP cases were in males(63.2%).The mean age at diagnosis was 31.8±19.3 years;a range of 32 weeks of gestation-81 years).23.5%of the patients did not report any symptoms.The most common clinical presentations were chest pain(35.2%)and dyspnoea(29.2%).The most commonly seen ECG changes were right axis deviation(28.7%)and right bundle branch block(23.9%).CAP was suspected or diagnosed by echocardiography in 20.1%of cases.The diagnosis was made by CT and/or MRI in 61.9%of cases.CAP was left-sided in 71.2%,complete in 23.1%,and right-sided in 5.7%.A concomitant congenital heart defect was found in 22.7%,especially in the form of atrial septal defect(6.5%)and patency of ductus arteriosus(2.8%).The pericardial repair was required in 12.9% of the incomplete forms of the disease.Never did the complete form require surgical correction.The outcome appeared favourable in the vast majority of cases,with just 18 deaths(7.3%).Discussion:The main limitation of this systematic review is that it is based just on case reports and case series,due to the lack of large studies on CAP.However,it represents the largest analysis in the field.Due to the rarity of CAP establishing an International Registry is recommended.

Hypertrophic cardiomyopathy secondary to deficiency in lysosomeassociated membrane protein-2: A case report

BACKGROUND Danon disease(DD),in which mutations in the X-linked lysosome-associated membrane protein-2(LAMP-2)gene result in hypertrophic cardiomyopathy,is a rare disease,reported primarily in small samples or cases.However,with the development of cardiac magnetic resonance imaging and genetic technology in recent years,the number of reports has increased.CASE SUMMARY We report a case of DD in an adolescent male patient,confirmed by genetic testing.The patient was admitted to our hospital with complaints of a three-year history of chest tightness and shortness of breath.His preliminary clinical diagnosis is hypertrophic cardiomyopathy.Our report includes the patient’s clinical course from hospital admission to death,step-by-step diagnosis,treatment course,and noninvasive imaging features.We highlight how a noninvasive diagnostic approach,based solely on clinical and imaging“red flags”for DD,can be used to achieve a diagnosis of DD with a high degree of confidence.CONCLUSION DD is a very dangerous cardiomyopathy,and it is necessary to achieve early diagnosis and treatment.