Feasibility of perfusion cardiovascular magnetic resonance in paediatric patients

Coronary artery anomalies: what are they? when to suspect? how to treat?-a narrative review

Background and Objective

In the literature have been widely discussed different classification criteria for coronary artery anomalies (CAAs), some authors have tried to categorize them only as "major" or "hemodynamically significant" anomalies versus "minor" or "not hemodynamically significant" ones. However, the most recent literature has concluded that all possible coronary anatomy should be taken into consideration in a comprehensive classification of CAAs. The aim of the article is to review the most recent literature regarding CAAs to provide a comprehensive overview of this challenging topic.

Methods

We propose a narrative overview of the most impactful and recent literature, synthetizing and re-elaborating the most important articles concerning CAAs.

Key Content and Findings

The important gap of knowledge on the specific characteristics of CAAs has led to a progressively increased interest of the current research in this field. Albeit their nature is still unclear, an increased awareness of their fatality is spreading among clinicians and the general population, mostly associated with their clinical relevance among young patients and athletes. On the other side, we do believe that clinical and hemodynamic repercussions are of crucial importance and should always be integrated to understand the true nature of this important pathology.

Conclusions

In the field of pediatric cardiology, CAAs are one of the most fascinating and studied subject. We propose a state-of-the art review to provide a comprehensive and systematic description and subsequently an approach to the epidemiological, pathophysiological, and clinical aspects of the most important CAAs in the pediatric population.

Tolerability and efficacy of a reduced dose adenosine stress cardiac magnetic resonance protocol under general anesthesia in infants and children

BACKGROUND

Intravenous adenosine induces pharmacological stress by causing vasodilatation and thus carries the risk of severe hypotension when combined with vasodilatory effects of anesthetic agents.

OBJECTIVE

This study describes our experience with a reduced dose adenosine cardiac magnetic resonance imaging (MRI) protocol in young children under general anesthesia (GA).

MATERIALS AND METHODS

This is a retrospective report of all patients from birth to 18 years who underwent adenosine stress cardiac MRI under GA between August 2018 and November 2022. Based on our anecdotal experience of severe adverse effects in patients receiving adenosine infusion under GA and in discussion with the pediatric anesthesia team, we developed a modified protocol starting at a dose of 110 mcg/kg/min with incremental escalation to a full dose of 140 mcg/kg/min to achieve desired hemodynamic effect.

RESULTS

Twenty-two children (mean age 6.5 years, mean weight 28 kg) satisfied the inclusion criteria. The diagnoses included Kawasaki disease (7), anomalous aortic origin of left coronary artery (3), anomalous aortic origin of right coronary artery (2), coronary fistula (3), repaired d-transposition of great arteries (2), repaired anomalous left coronary artery from pulmonary artery (2), repaired truncus arteriosus with left coronary artery occlusion (1), extracardiac-Fontan with left coronary artery myocardial bridge (1), and post heart transplantation (1). Nine patients needed dose escalation beyond 110 mcg/kg/min. Two patients had transient hypotension during testing (systemic blood pressure drop > 25 mmHg). No patient developed significant heart block or bronchospasm. Six patients (repeat study in one) demonstrated inducible perfusion defects (27%) on stress perfusion sequences-5 of whom had confirmed significant coronary abnormalities on angiography or direct surgical inspection.

CONCLUSION

A reduced/incremental dose adenosine stress cardiac MRI protocol under GA in children is safe and feasible. This avoids severe hypotension which is both unsafe and may result in inaccurate data.

Congenital coronary artery anomalies in sports medicine. Why to know them

The anomalous origin of a coronary artery (AOCA) is a challenging topic, due to its rarity, the complexity of the pathophysiological aspects, the clinical presentation (often silent), the difficulty of diagnosis, and the potential risk of causing acute cardiovascular events up to sudden cardiac death, particularly when triggered by heavy physical exercise or sport practice. Increasing interest in sport medical literature is being given to this topic. This paper reviews current knowledge of AOCAs in the specific context of the athletic setting addressing epidemiological and pathophysiological aspects, diagnostic work-up, sports participation, individual risk assessment, therapeutic options, and return to play decision after surgery.

Cardiovascular Magnetic Resonance from Fetal to Adult Life-Indications and Challenges: A State-of-the-Art Review

Cardiovascular magnetic resonance (CMR) imaging offers a comprehensive, non-invasive, and radiation-free imaging modality, which provides a highly accurate and reproducible assessment of cardiac morphology and functions across a wide spectrum of cardiac conditions spanning from fetal to adult life. It minimises risks to the patient, particularly the risks associated with exposure to ionising radiation and the risk of complications from more invasive haemodynamic assessments. CMR utilises high spatial resolution and provides a detailed assessment of intracardiac and extracardiac anatomy, ventricular and valvular function, and flow haemodynamic and tissue characterisation, which aid in the diagnosis, and, hence, with the management of patients with cardiac disease. This article aims to discuss the role of CMR and the indications for its use throughout the different stages of life, from fetal to adult life.

Dobutamine Stress Cardiac MRI in Pediatric Patients with Suspected Coronary Artery Disease

Following current practice, pediatric patients with treated congenital coronary malformations or acquired coronary disease undergo Cardio-Pulmonary Exercise Test (CPET), stress Echocardiography and Electrocardiography (sEcho, sEKG), and Coronary Angiography (CA). Stress cMRI can assess cardiac function, myocardial viability, and stress/rest perfusion deficit-without radiation exposure, general anesthesia, and hospitalization-in a single non-invasive exam. The aim of our pilot study is to assess the feasibility and diagnostic accuracy of Dobutamine stress cMRI compared to the current procedures (sEcho, CPET, CA). The prospective study is focused on pediatric patients, at risk for or with previously diagnosed coronary artery disease: d-looped TGA after arterial Switch, Kawasaki disease, and anomalous origin of left coronary artery from pulmonary artery (ALCAPA) after coronary artery reimplantation. We have compared the results of MRI coronary angiography, and Dobutamine stress cMRI with traditional tests. All these diagnostic exams were acquired in a timeframe of 3 month, in a blinded fashion. All the 13 patients (age: 12 ± 2 years, median 12,7 y) recruited, completed the study without major adverse events. The mean heart rate-pressure product was 25,120 ± 5110 bpm x mm Hg. The target heart rate of 85% of the maximal theoretical was reached by 10 (77%) patients. The comparison between cardiac MRI coronarography versus the gold standard Coronary Angiography to identify the patency of the origin and the proximal pathway of the coronary arteries shows a sensitivity of 100% (confidence interval: 2,5-100%), specificity 92% (confidence interval: 64-100%). The stress test was well tolerated for the 77% of the patients and completed by the totality of patients (Table 3). Three patients (23%) had mild symptoms: nausea, vomiting, or general discomfort. In pediatric patients with a potential or definite diagnosis of coronary artery disease, stress cMRI combines an effective assessment of proximal coronary arteries anatomy with cardiac function, myocardial perfusion, and viability in a single examination. Stress cMRI can be proposed as alternative, standalone test.

The Use of Stress Cardiovascular Imaging in Pediatric Population

Although not frequent in the pediatric population, ischemia could occur in children due to several congenital and acquired disease. Stress imaging is key for the non-invasive evaluation of myocardial abnormalities and perfusion defect in this clinical setting. Moreover, beyond ischemia assessment, it can provide complementary diagnostic and prognostic information in valvular heart disease and cardiomyopathies. When performed using cardiovascular magnetic resonance, it could detect, in addition, myocardial fibrosis and infarction, increasing the diagnostic yield. Several imaging modalities are currently available for the evaluation of stress myocardial perfusion. Advances in technologies have also increased the feasibility, safety and availability of these modalities in the pediatric age group. However, despite the established role of stress imaging and its increasing use in daily clinical practice, there are currently no specific guidelines, and little data are available in the literature on this topic. The aim of this review is to summarize the most recent evidence on pediatric stress imaging and its clinical application with a focus on the advantages and limitations of each imaging modality currently available.

Cardiovascular magnetic resonance for the evaluation of patients with cardiovascular disease: An overview of current indications, limitations, and procedures

Cardiovascular disease (CVD) is the most common cause of morbidity/mortality worldwide. Early diagnosis is the key to improve CVD prognosis, and cardiovascular imaging plays a crucial role in this direction. Echocardiography is the most commonly used imaging modality. However, the need for early diagnosis/treatment favors the development of modalities providing information about tissue characterization beyond echocardiography. In this context, the rapid evolution of cardiovascular magnetic resonance (CMR) led to the coexistence of cardiologists and radiologists in the CMR field. Our aim was to provide an overview of indications, sequences, and reporting of CMR findings in various CVDs. The indications/limitations of CMR as well as the pathophysiological significance of various sequences in adult/pediatric CVDs are presented and discussed in detail. The role of CMR indices in the evaluation of the most common clinical scenarios in cardiology and their impact on CVD diagnosis/prognosis were analyzed in detail. Additionally, the comparison of CMR versus other imaging modalities is also discussed. Finally, future research directions are presented. CMR can provide cardiac tissue characterization and biventricular/biatrial functional assessment in the same examination, allowing for early and accurate identification of important subclinical abnormalities, before clinically overt CVD takes place.

Cardiovascular Magnetic Resonance Imaging Patterns in Rare Cardiovascular Diseases

Rare cardiovascular diseases (RCDs) have low incidence but major clinical impact. RCDs' classification includes Class I-systemic circulation, Class II-pulmonary circulation, Class III-cardiomyopathies, Class IV-congenital cardiovascular diseases (CVD), Class V-cardiac tumors and CVD in malignancy, Class VI-cardiac arrhythmogenic disorders, Class VII-CVD in pregnancy, Class VIII-unclassified rare CVD. Cardiovascular Magnetic Resonance (CMR) is useful in the diagnosis/management of RCDs, as it performs angiography, function, perfusion, and tissue characterization in the same examination. Edema expressed as a high signal in STIRT2 or increased T2 mapping is common in acute/active inflammatory states. Diffuse subendocardial fibrosis, expressed as diffuse late gadolinium enhancement (LGE), is characteristic of microvascular disease as in systemic sclerosis, small vessel vasculitis, cardiac amyloidosis, and metabolic disorders. Replacement fibrosis, expressed as LGE, in the inferolateral wall of the left ventricle (LV) is typical of neuromuscular disorders. Patchy LGE with concurrent edema is typical of myocarditis, irrespective of the cause. Cardiac hypertrophy is characteristic in hypertrophic cardiomyopathy (HCM), cardiac amyloidosis (CA) and Anderson-Fabry Disease (AFD), but LGE is located in the IVS, subendocardium and lateral wall in HCM, CA and AFD, respectively. Native T1 mapping is increased in HCM and CA and reduced in AFD. Magnetic resonance angiography provides information on aortopathies, such as Marfan, Turner syndrome and Takayasu vasculitis. LGE in the right ventricle is the typical finding of ARVC, but it may involve LV, leading to the diagnosis of arrhythmogenic cardiomyopathy. Tissue changes in RCDs may be detected only through parametric imaging indices.

Cardiovascular magnetic resonance in autoimmune rheumatic diseases: a clinical consensus document by the European Association of Cardiovascular Imaging

Autoimmune rheumatic diseases (ARDs) involve multiple organs including the heart and vasculature. Despite novel treatments, patients with ARDs still experience a reduced life expectancy, partly caused by the higher prevalence of cardiovascular disease (CVD). This includes CV inflammation, rhythm disturbances, perfusion abnormalities (ischaemia/infarction), dysregulation of vasoreactivity, myocardial fibrosis, coagulation abnormalities, pulmonary hypertension, valvular disease, and side-effects of immunomodulatory therapy. Currently, the evaluation of CV involvement in patients with ARDs is based on the assessment of cardiac symptoms, coupled with electrocardiography, blood testing, and echocardiography. However, CVD may not become overt until late in the course of the disease, thus potentially limiting the therapeutic window for intervention. More recently, cardiovascular magnetic resonance (CMR) has allowed for the early identification of pathophysiologic structural/functional alterations that take place before the onset of clinically overt CVD. CMR allows for detailed evaluation of biventricular function together with tissue characterization of vessels/myocardium in the same examination, yielding a reliable assessment of disease activity that might not be mirrored by blood biomarkers and other imaging modalities. Therefore, CMR provides diagnostic information that enables timely clinical decision-making and facilitates the tailoring of treatment to individual patients. Here we review the role of CMR in the early and accurate diagnosis of CVD in patients with ARDs compared with other non-invasive imaging modalities. Furthermore, we present a consensus-based decision algorithm for when a CMR study could be considered in patients with ARDs, together with a standardized study protocol. Lastly, we discuss the clinical implications of findings from a CMR examination.

Society for Cardiovascular Magnetic Resonance/European Society of Cardiovascular Imaging/American Society of Echocardiography/Society for Pediatric Radiology/North American Society for Cardiovascular Imaging Guidelines for the use of cardiovascular magnetic resonance in pediatric congenital and acquired heart disease : Endorsed by The American Heart Association

Cardiovascular magnetic resonance (CMR) has been utilized in the management and care of pediatric patients for nearly 40 years. It has evolved to become an invaluable tool in the assessment of the littlest of hearts for diagnosis, pre-interventional management and follow-up care. Although mentioned in a number of consensus and guidelines documents, an up-to-date, large, stand-alone guidance work for the use of CMR in pediatric congenital 36 and acquired 35 heart disease endorsed by numerous Societies involved in the care of these children is lacking. This guidelines document outlines the use of CMR in this patient population for a significant number of heart lesions in this age group and although admittedly, is not an exhaustive treatment, it does deal with an expansive list of many common clinical issues encountered in daily practice.

Society for Cardiovascular Magnetic Resonance/European Society of Cardiovascular Imaging/American Society of Echocardiography/Society for Pediatric Radiology/North American Society for Cardiovascular Imaging Guidelines for the Use of Cardiac Magnetic Resonance in Pediatric Congenital and Acquired Heart Disease: Endorsed by The American Heart Association

Cardiovascular magnetic resonance has been utilized in the management and care of pediatric patients for nearly 40 years. It has evolved to become an invaluable tool in the assessment of the littlest of hearts for diagnosis, pre-interventional management and follow-up care. Although mentioned in a number of consensus and guidelines documents, an up-to-date, large, stand-alone guidance work for the use of cardiovascular magnetic resonance in pediatric congenital 36 and acquired 35 heart disease endorsed by numerous Societies involved in the care of these children is lacking. This guidelines document outlines the use of cardiovascular magnetic resonance in this patient population for a significant number of heart lesions in this age group and although admittedly, is not an exhaustive treatment, it does deal with an expansive list of many common clinical issues encountered in daily practice.

A Comprehensive Assessment of Cardiomyopathies through Cardiovascular Magnetic Resonance: Focus on the Pediatric Population

Cardiomyopathies (CMPs) are a heterogeneous group of diseases that involve the myocardium and result in systolic or diastolic impairment of the cardiac muscle, potentially leading to heart failure, malignant arrhythmias, or sudden cardiac death. Occurrence in pediatric age is rare but has been associated with worse outcomes. Non-invasive cardiac imaging techniques, integrated with clinical, genetic, and electrocardiographic data, have shown a pivotal role in the clinical work-up of such diseases by defining structural alterations and assessing potential complications. Above all modalities, cardiovascular magnetic resonance (CMR) has emerged as a powerful tool complementary to echocardiography to confirm diagnosis, provide prognostic information and guide therapeutic strategies secondary to its high spatial and temporal resolution, lack of ionizing radiation, and good reproducibility. Moreover, CMR can provide in vivo tissue characterization of the myocardial tissue aiding the identification of structural pathologic changes such as replacement or diffuse fibrosis, which are predictors of worse outcomes. Large prospective randomized studies are needed for further validation of CMR in the context of childhood CMPs. This review aims to highlight the role of advanced imaging with CMR in CMPs with particular reference to the dilated, hypertrophic and non-compacted phenotypes, which are more commonly seen in children.

Automated Quantitative Stress Perfusion Cardiac Magnetic Resonance in Pediatric Patients

Background: Myocardial ischemia occurs in pediatrics, as a result of both congenital and acquired heart diseases, and can lead to further adverse cardiac events if untreated. The aim of this work is to assess the feasibility of fully automated, high resolution, quantitative stress myocardial perfusion cardiac magnetic resonance (CMR) in a cohort of pediatric patients and to evaluate its agreement with the coronary anatomical status of the patients. Methods: Fourteen pediatric patients, with 16 scans, who underwent dual-bolus stress perfusion CMR were retrospectively analyzed. All patients also had anatomical coronary assessment with either CMR, CT, or X-ray angiography. The perfusion CMR images were automatically processed and quantified using an analysis pipeline previously developed in adults. Results: Automated perfusion quantification was successful in 15/16 cases. The coronary perfusion territories supplied by vessels affected by a medium/large aneurysm or stenosis (according to the AHA guidelines), induced by Kawasaki disease, an anomalous origin, or interarterial course had significantly reduced myocardial blood flow (MBF) (median (interquartile range), 1.26 (1.05, 1.67) ml/min/g) as compared to territories supplied by unaffected coronaries [2.57 (2.02, 2.69) ml/min/g, p < 0.001] and territories supplied by vessels with a small aneurysm [2.52 (2.45, 2.83) ml/min/g, p = 0.002]. Conclusion: Automatic CMR-derived MBF quantification is feasible in pediatric patients, and the technology could be potentially used for objective non-invasive assessment of ischemia in children with congenital and acquired heart diseases.

Myocardial Stress Perfusion MRI Using Regadenoson: A Weight-based Approach in Infants and Young Children

Purpose

To determine the safety and feasibility of stress cardiac MRI by using weight-based dosing of regadenoson in patients less than 40 kg and whether stress cardiac MRI affects patient management.

Materials and Methods

All patients less than 40 kg undergoing stress cardiac MRI by using weight-based dosing (8 μg/kg) of regadenoson were included in this retrospective single-center study. Hemodynamic response, adverse events, and cardiac MRI abnormalities in myocardial perfusion, wall motion, and delayed enhancement were evaluated. Patient management based on the results of the stress cardiac MRI were evaluated.

Results

Forty-six consecutive stress cardiac MRI examinations were performed in 36 patients (median age, 9.0 years; age range, 2 months to 13.9 years) with congenital and acquired heart disease. Thirty-one of 46 (67.4%) studies were performed with the use of sedation. A myocardial perfusion defect was present in 20 of 46 (43.5%) studies, five with inducible defects only, and the remaining 15 with fixed or irreversible defects. In the 46 total studies, there were no major adverse events and nine (19.6%) minor adverse events including emesis (n = 1) and transient hypotension requiring pharmacologic intervention in eight patients who were all sedated. Sedation was an independent predictor for hypotension (P =.040). Twenty-six negative studies had no coronary interventions performed, and of the 20 positive studies, 15 were referred for catheterization, eight of which underwent coronary interventions.

Conclusion

Weight-based dosing of regadenoson for stress cardiac MRI was safe and feasible in infants and young children and played an integral role in the outcome and treatment decisions for children with coronary artery disease.© RSNA, 2019.

Pharmacologic stress cardiovascular magnetic resonance in the pediatric population: A review of the literature, proposed protocol, and two examples in patients with Kawasaki disease

Pharmacologic stress cardiovascular magnetic resonance (PSCMR) is a well-established and reliable diagnostic tool for evaluation of coronary artery disease in the adult population. Stress imaging overall and PSCMR in particular is less utilized in the pediatric population with limited reported data. In this review, we highlight the potential use of PSCMR in specific pediatric cohorts with congenital and acquired heart disease, and we review the reported experience. A suggested protocol is presented in addition to two case examples of patients with Kawasaki disease where PSCMR aided decision making.

Myocardial Stress Perfusion MRI: Experience in Pediatric and Young-Adult Patients Following Arterial Switch Operation Utilizing Regadenoson

Dextro-transposition of the great arteries (D-TGA) is one of the most common cyanotic heart lesions. The arterial switch operation (ASO) is the preferred surgical palliation for D-TGA. One of the primary concerns following the ASO is complications arising from the coronary artery transfer. There is a need for myocardial perfusion assessment within ASO patients. There is no report on the utility of regadenoson as a stress agent in children following ASO. Our objective was to observe the safety and feasibility of regadenoson as a pharmacologic stressor for perfusion cardiac MR in a pilot cohort of pediatric and young-adult patients who have undergone ASO. We reviewed our initial experience with regadenoson stress cardiac MR in 36 pediatric and young-adult patients 15.1 ± 4.5 years (range 0.2-22 years) with history of ASO. The weight was 61.6 ± 21.5 kg (range 3.8-93 kg). All patients underwent cardiac MR because of concern for ischemia. Subjects' heart rate and blood pressure were monitored and pharmacologic stress was induced by injection of regadenoson. We evaluated their hemodynamic response and adverse effects using changes in vital signs and onset of symptoms. A pediatric cardiologist and radiologist qualitatively assessed myocardial perfusion and viability images. All stress cardiac MR examinations were completed without adverse events. Resting heart rate was 72 ± 13 beats per minute (bpm) and rose to peak of 120 ± 17 bpm (95 ± 50% increase, p < 0.005) with regadenoson. Image quality was considered good or diagnostic in all cases. A total of 11/36 (31%) patients had a perfusion defect on the stress FPP images. 14 of the 36 patients (39%) underwent cardiac catheterization within 6 months of the CMR and the findings showed excellent agreement. Regadenoson may be a useful coronary hyperemia agent to utilize for pediatric patients following arterial switch procedure when there is concern for ischemia. The ability to administer as a single bolus with one IV makes it advantageous in pediatrics. In a limited number of cases, regadenoson stress perfusion showed excellent agreement with cardiac catheterization.

Utility of adenosine stress perfusion CMR to assess paediatric coronary artery disease

Aims

Cardiovascular magnetic resonance (CMR), using adenosine stress perfusion and late-gadolinium enhancement (LGE), is becoming the 'gold standard' non-invasive imaging modality in the assessment of adults with coronary artery disease (CAD). However, despite its proved feasibility in paediatric patients, clinical utility has not been demonstrated. Therefore, this study aims to establish the role of adenosine stress perfusion CMR as a screening test in paediatric patients with acquired or congenital CAD.

Methods and results

A total of 58 paediatric patients underwent 61 consecutive clinically indicated coronary artery assessments for diagnostic and clinical decision-making purposes. The diagnosis was based on X-ray or computed tomography coronary angiography for anatomy, adenosine stress CMR imaging for myocardial perfusion and LGE for tissue characterization. Two studies were aborted because of unwanted side effects of adenosine stress, thus 59 studies were completed in 56 patients [median age 14.1 years (interquartile range 10.9-16.2)]. When compared with coronary anatomical imaging, adenosine stress perfusion CMR performed as follows: sensitivity 100% (95% confidence interval, CI: 71.6-100%), specificity 98% (95% CI: 86.7-99.9%), positive predictive value (PPV) 92.9% (95% CI: 64.2-99.6%), and negative predictive value 100% (95% CI: 89.9-100%).

Conclusion

In paediatric CAD, adenosine stress perfusion CMR imaging is adequate as an initial, non-invasive screening test for the identification of significant coronary artery lesions, with anatomical imaging used to confirm the extent of the culprit lesion.

Magnetic Resonance Myocardial Perfusion Imaging: Safety and Indications in Pediatrics and Young Adults

The purpose of this study was to assess the safety and indications for cardiac magnetic resonance (CMR) with myocardial perfusion imaging (MPI) in a cohort of children and young adults. A retrospective review of 178 children and young adults who underwent CMR with MPI was performed. Studies were categorized based on study protocols as MPI with resting perfusion only, adenosine stress MPI, exercise-induced stress MPI, and MPI for cardiac mass diagnosis. Relevant clinical history, exam indications, and adverse reactions following gadolinium-based contrast agent and adenosine administration were recorded. Studies were reviewed for the presence of myocardial perfusion defects, wall motion abnormalities, and delayed myocardial enhancement. The most common indications from MPI were congenital heart disease (CHD), Kawasaki disease, anomalous coronary artery, or myocardial mass characterization. Of these, 51% were protocoled with adenosine stress, 23% without stress, 6% with exercise stress, and 20% for cardiac mass evaluation. Excluding patients for myocardial mass evaluation, MPI defects were present in 16% (14 with adenosine stress, 1 with exercise stress, 8 on resting studies only). For cardiac mass evaluation, a mass was confirmed in 58%. No adverse reactions occurred with intravenous administration of a gadolinium-based contrast agent. Three self-limited adverse reactions, 2 patients with chest pain, and 1 patient with bradycardia, occurred following adenosine administration. MPI is a safe modality for the evaluation of pediatric and young adults with minimal adverse events. The most common indications for MPI were for the evaluation of CHD, Kawasaki disease, anomalous coronary artery, or myocardial mass characterization.

Radiation dose management for pediatric cardiac computed tomography: a report from the Image Gently 'Have-A-Heart' campaign

Children with congenital or acquired heart disease can be exposed to relatively high lifetime cumulative doses of ionizing radiation from necessary medical imaging procedures including radiography, fluoroscopic procedures including diagnostic and interventional cardiac catheterizations, electrophysiology examinations, cardiac computed tomography (CT) studies, and nuclear cardiology examinations. Despite the clinical necessity of these imaging studies, the related ionizing radiation exposure could pose an increased lifetime attributable cancer risk. The Image Gently "Have-A-Heart" campaign is promoting the appropriate use of medical imaging studies in children with congenital or acquired heart disease while minimizing radiation exposure. The focus of this manuscript is to provide a comprehensive review of radiation dose management and CT performance in children with congenital or acquired heart disease.

The impact of dual-source parallel radiofrequency transmission with patient-adaptive shimming on the cardiac magnetic resonance in children at 3.0 T

The cardiac magnetic resonance (CMR) of children at 3.0 T presents a unique set of technical challenges because of their small cardiac anatomical structures, fast heart rates, and the limited ability to keep motionless and hold breathe, which could cause problems associated with field inhomogeneity and degrade the image quality. The aim of our study was to evaluate the effect of dual-source parallel radiofrequency (RF) transmission on the B1 homogeneity and image quality in children with CMR at 3.0 T. The study was approved by the institutional ethics committee and written informed consent was obtained. A total of 30 free-breathing children and 30 breath-hold children performed CMR examinations with dual-source and single-source RF transmission. The B1 homogeneity, contrast ratio (CR) of cine images, and off-resonance artifacts in cine images between dual-source and single-source RF transmission were assessed in free-breathing and breath-hold groups, respectively. In both free-breathing and breath-hold groups, higher mean percentage of flip angle (free-breathing group: 104.2 ± 4.6 vs 95.5 ± 6.3, P < .001; breath-hold group: 101.5 ± 5.1 vs 92.5 ± 6.3, P < .001) and lower coefficient of variation (free-breathing group: 0.06 ± 0.02 vs 0.09 ± 0.03, P < .001; breath-hold group: 0.07 ± 0.03 vs 0.10 ± 0.04, P = .005) were found with dual-source than with single-source RF transmission. Both the CRs in the horizontal long axis (HLA) and short axis of cine images with dual-source RF transmission was improved (P < .05 for all). The scores of off-resonance artifacts in the HLA with dual-source RF transmission were higher in both free-breathing and breath-hold groups (P < .05 for all), with substantial interreader agreement (kappa values from 0.68 to 0.74). Compared with conventional single-source, dual-source parallel RF transmission could significantly improve the B1 homogeneity and image quality for CMR in children at 3.0 T. This technology could be taken into account in CMR for children with cardiac diseases.

Myocardial stress perfusion magnetic resonance: initial experience in a pediatric and young adult population using regadenoson

BACKGROUND

Dipyridamole and adenosine are traditional pharmacological stressors for myocardial perfusion. Regadenoson, a selective adenosine A2A agonist, has a lower side effect profile with lower incidence of bronchospasm and bradycardia. There is a growing need for myocardial perfusion assessment within pediatrics. There is no report on the utility of regadenoson as a stress agent in children.

OBJECTIVE

To observe the safety and feasibility of regadenoson as a pharmacologic stressor for perfusion cardiac MR in a pilot cohort of pediatric patients weighing more than 40 kg who have congenital heart disease and pediatric acquired heart disease.

MATERIALS AND METHODS

We reviewed our initial experience with regadenoson stress cardiac MR in 31 pediatric patients 15.8 ± 1.7 years (range 12-22 years) with congenital heart disease and acquired heart disease. Mean patient weight was 60 ± 15 kg (range of 40-93 kg). All patients underwent cardiac MR because of concern for ischemia. The cohort included a heterogeneous group of patients at a pediatric institution with potential risk for ischemia. Subjects' heart rate and blood pressure were monitored and pharmacologic stress was induced by injection of 400 mcg of regadenoson. We evaluated their hemodynamic response and adverse effects using changes in vital signs and onset of symptoms. A pediatric cardiologist and radiologist qualitatively assessed myocardial perfusion and viability images.

RESULTS

One child was unable to complete the stress perfusion portion of the examination, but did complete the remaining portion of the CMR. Resting heart rate was 72 ± 14 beats per minute (bpm) and rose to peak of 124 ± 17 bpm (95 ± 50% increase, P < 0.005) with regadenoson. Image quality was considered good or diagnostic in all cases. Three patients had irreversible perfusion defects. Four patients had reversible perfusion defects. Nine of the patients underwent cardiac catheterization with angiography and the findings showed excellent agreement.

CONCLUSION

Regadenoson might be a safe and feasible pharmacologic stress agent for use in cardiac MR in older pediatric patients with congenital heart disease and acquired heart disease. The ease of use as a bolus and the advantage of a prolonged hyperemia make its use appealing in pediatrics. In a limited number of cases, regadenoson stress perfusion showed excellent agreement with cardiac catheterization. Regadenoson might be a viable pharmacologic stress agent in this population.

Stress perfusion magnetic resonance imaging to detect coronary artery lesions in children

BACKGROUND

Stress perfusion cardiovascular magnetic resonance (CMR) is used widely in adult ischemic heart disease, but data in children is limited. We sought to evaluate feasibility, accuracy and prognostic value of stress CMR in children with suspected coronary artery disease (CAD).

METHODS

Stress CMR was reviewed from two pediatric centers over 5 years using a standard pharmacologic protocol. Wall motion abnormalities, perfusion deficits and late enhancement were correlated with coronary angiogram (CAG) when available, and clinical status at 1 year follow-up for major adverse cardiovascular events (MACE; coronary revascularization, non-fatal myocardial infarction and death due to CAD) was recorded.

RESULTS

Sixty-four stress perfusion CMR studies in 48 children (10.9 ± 4.8 years) using adenosine; 59 (92%) and dipyridamole; 5 (8%), were reviewed. Indications were Kawasaki disease (39%), post arterial switch operation (12.5%), post heart transplantation (12.5%), post anomalous coronary artery repair (11%), chest pain (11%), suspected myocarditis or CAD (3%), post coronary revascularization (3%), and others (8%). Twenty-six studies were performed under sedation. Of all studies performed, 66% showed no evidence of ischemia or infarction, 28% had perfusion deficits and 6% had late gadolinium enhancement (LGE) without perfusion deficit. Compared to CAG, the positive predictive value (PPV) of stress CMR was 80% with negative predictive value (NPV) of 88%. At 1 year clinical follow-up, the PPV and NPV of stress CMR to predict MACE were 78 and 98%.

CONCLUSION

Stress-perfusion CMR, in combination with LGE and wall motion-analysis is a feasible and an accurate method of diagnosing CAD in children. In difficult cases, it also helps guide clinical intervention by complementing conventional CAG with functional information.

Cardiovascular magnetic resonance: Diagnostic utility and specific considerations in the pediatric population

Cardiovascular magnetic resonance is a non-invasive imaging modality which is emerging as important tool for the investigation and management of pediatric cardiovascular disease. In this review we describe the key technical and practical differences between scanning children and adults, and highlight some important considerations that must be taken into account for this patient population. Using case examples commonly seen in clinical practice, we discuss the important clinical applications of cardiovascular magnetic resonance, and briefly highlight key future developments in this field.

Indications for cardiovascular magnetic resonance in children with congenital and acquired heart disease: an expert consensus paper of the Imaging Working Group of the AEPC and the Cardiovascular Magnetic Resonance Section of the EACVI

This article provides expert opinion on the use of cardiovascular magnetic resonance (CMR) in young patients with congenital heart disease (CHD) and in specific clinical situations. As peculiar challenges apply to imaging children, paediatric aspects are repeatedly discussed. The first section of the paper addresses settings and techniques, including the basic sequences used in paediatric CMR, safety, and sedation. In the second section, the indication, application, and clinical relevance of CMR in the most frequent CHD are discussed in detail. In the current era of multimodality imaging, the strengths of CMR are compared with other imaging modalities. At the end of each chapter, a brief summary with expert consensus key points is provided. The recommendations provided are strongly clinically oriented. The paper addresses not only imagers performing CMR, but also clinical cardiologists who want to know which information can be obtained by CMR and how to integrate it in clinical decision-making.

Indications for cardiovascular magnetic resonance in children with congenital and acquired heart disease: an expert consensus paper of the Imaging Working Group of the AEPC and the Cardiovascular Magnetic Resonance Section of the EACVI

This article provides expert opinion on the use of cardiovascular magnetic resonance (CMR) in young patients with congenital heart disease (CHD) and in specific clinical situations. As peculiar challenges apply to imaging children, paediatric aspects are repeatedly discussed. The first section of the paper addresses settings and techniques, including the basic sequences used in paediatric CMR, safety, and sedation. In the second section, the indication, application, and clinical relevance of CMR in the most frequent CHD are discussed in detail. In the current era of multimodality imaging, the strengths of CMR are compared with other imaging modalities. At the end of each chapter, a brief summary with expert consensus key points is provided. The recommendations provided are strongly clinically oriented. The paper addresses not only imagers performing CMR, but also clinical cardiologists who want to know which information can be obtained by CMR and how to integrate it in clinical decision-making.

Evaluation of a comprehensive cardiovascular magnetic resonance protocol in young adults late after the arterial switch operation for d-transposition of the great arteries

BACKGROUND

In adults with prior arterial switch operation (ASO) for d-transposition of the great arteries, the need for routine coronary artery assessment and evaluation for silent myocardial ischemia is not well defined. In this observational study we aimed to determine the value of a comprehensive cardiovascular magnetic resonance (CMR) protocol for the detection of coronary problems in adults with prior ASO for d-transposition of the great arteries.

METHODS

Adult ASO patients (≥18 years of age) were recruited consecutively. Patients underwent a comprehensive stress perfusion CMR protocol that included measurement of biventricular systolic function, myocardial scar burden, coronary ostial assessment and myocardial perfusion during vasodilator stress by perfusion CMR. Single photon emission computed tomography (SPECT) was performed on the same day as a confirmatory second imaging modality. Stress studies were visually assessed for perfusion defects (qualitative analysis). Additionally, myocardial blood flow was quantitatively analysed from mid-ventricular perfusion CMR images. In unclear cases, CT coronary angiography or conventional angiography was done.

RESULTS

Twenty-seven adult ASO patients (mean age 23 years, 85% male, 67% with a usual coronary pattern; none with a prior coronary artery complication) were included in the study. CMR stress perfusion was normal in all 27 patients with no evidence of inducible perfusion defects. In 24 cases the coronary ostia could conclusively be demonstrated to be normal. There was disagreement between CMR and SPECT for visually-assessed perfusion defects in 54% of patients with most disagreement due to false positive SPECT.

CONCLUSIONS

Adult ASO survivors in this study had no CMR evidence of myocardial ischemia, scar or coronary ostial abnormality. Compared to SPECT, CMR provides additional valuable information about the coronary artery anatomy. The data shows that the asymptomatic and clinically stable adult ASO patient has a low pre-test probability for inducible ischemia. In this situation it is likely that routine evaluation with stress CMR is unnecessary.

The value of stress perfusion cardiovascular magnetic resonance imaging for patients referred from the adult congenital heart disease clinic: 5-year experience at the Toronto General Hospital

BACKGROUND

Vasodilator stress perfusion cardiovascular magnetic resonance imaging is a clinically useful tool for detection of clinically significant myocardial ischaemia in adults. We report our 5-year retrospective experience with perfusion cardiovascular magnetic resonance in a large, quarternary adult congenital heart disease centre.

METHODS

We reviewed all cases of perfusion cardiovascular magnetic resonance in patients referred from the adult congenital heart disease service. Dipyridamole stress perfusion cardiovascular magnetic resonance was undertaken on commercially available 1.5 and 3 T cardiovascular magnetic resonance scanners. Late gadolinium enhancement imaging was performed 8-10 minutes after completion of the rest perfusion sequence. Navigator whole-heart coronary magnetic resonance angiography was also performed where feasible. RESULTS of stress cardiovascular magnetic resonance were correlated with complementary imaging studies, surgery, and clinical outcomes.

RESULTS

Over 5 years, we performed 34 stress perfusion cardiovascular magnetic resonance examinations (11 positive). In all, 84% of patients had further investigations for ischaemia in addition to cardiovascular magnetic resonance. Within a subgroup of 19 patients who had definitive alternative assessment of their coronary arteries, stress perfusion cardiovascular magnetic resonance demonstrated a sensitivity of 82% and specificity of 100%. Of the 34 studies, two were false negatives, in which the aetiology of ischaemia was extrinsic arterial compression rather than intrinsic coronary luminal narrowing. Coronary abnormalities were identified in 71% of cases who had coronary magnetic resonance angiography.

CONCLUSION

Stress perfusion cardiovascular magnetic resonance is a useful and accurate tool for investigation of myocardial ischaemia in an adult congenital heart disease population with suspected non-atherosclerotic coronary abnormalities.

Guidelines and protocols for cardiovascular magnetic resonance in children and adults with congenital heart disease: SCMR expert consensus group on congenital heart disease

Cardiovascular magnetic resonance (CMR) has taken on an increasingly important role in the diagnostic evaluation and pre-procedural planning for patients with congenital heart disease. This article provides guidelines for the performance of CMR in children and adults with congenital heart disease. The first portion addresses preparation for the examination and safety issues, the second describes the primary techniques used in an examination, and the third provides disease-specific protocols. Variations in practice are highlighted and expert consensus recommendations are provided. Indications and appropriate use criteria for CMR examination are not specifically addressed.

The role of cardiovascular magnetic resonance in pediatric congenital heart disease

Cardiovascular magnetic resonance (CMR) has expanded its role in the diagnosis and management of congenital heart disease (CHD) and acquired heart disease in pediatric patients. Ongoing technological advancements in both data acquisition and data presentation have enabled CMR to be integrated into clinical practice with increasing understanding of the advantages and limitations of the technique by pediatric cardiologists and congenital heart surgeons. Importantly, the combination of exquisite 3D anatomy with physiological data enables CMR to provide a unique perspective for the management of many patients with CHD. Imaging small children with CHD is challenging, and in this article we will review the technical adjustments, imaging protocols and application of CMR in the pediatric population.

Review of journal of cardiovascular magnetic resonance 2010

There were 75 articles published in the Journal of Cardiovascular Magnetic Resonance (JCMR) in 2010, which is a 34% increase in the number of articles since 2009. The quality of the submissions continues to increase, and the editors were delighted with the recent announcement of the JCMR Impact Factor of 4.33 which showed a 90% increase since last year. Our acceptance rate is approximately 30%, but has been falling as the number of articles being submitted has been increasing. In accordance with Open-Access publishing, the JCMR articles go on-line as they are accepted with no collating of the articles into sections or special thematic issues. Last year for the first time, the Editors summarized the papers for the readership into broad areas of interest or theme, which we felt would be useful to practitioners of cardiovascular magnetic resonance (CMR) so that you could review areas of interest from the previous year in a single article in relation to each other and other recent JCMR articles 1. This experiment proved very popular with a very high rate of downloading, and therefore we intend to continue this review annually. The papers are presented in themes and comparison is drawn with previously published JCMR papers to identify the continuity of thought and publication in the journal. We hope that you find the open-access system increases wider reading and citation of your papers, and that you will continue to send your quality manuscripts to JCMR for publication.

Cardiovascular magnetic resonance findings in repaired anomalous left coronary artery to pulmonary artery connection (ALCAPA)

BACKGROUND

Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) is a rare coronary artery anomaly. This study shows the role of cardiovascular magnetic resonance (CMR) in assessing young patients following surgical repair of ALCAPA.

METHODS

6 patients, aged 9-21 years, with repaired ALCAPA (2 Tackeuchi method, 4 direct re-implantation) underwent CMR because of clinical suspicion of myocardial ischemia. Imaging used short and long axis cine images (assess ventricular function), late-gadolinium enhancement (LGE) (detect segmental myocardial fibrosis), adenosine stress perfusion (detect reversible ischaemia) and 3D whole-heart imaging (visualize proximal coronary arteries).

RESULTS

The left ventricular (LV) global systolic function was preserved in all patients (mean LV ejection fraction = 62.7% ± 4.23%). The LV volumes were within the normal ranges, (mean indexed LVEDV = 75.4 ± 3.5 ml/m², LVESV = 31.6 ± 9.4 ml/m²). In 1 patient, hypokinesia of the anterior segments was visualized. Five patients showed sub-endocardial LGE involving the basal, antero-lateral wall and the anterior papillary muscle. Three patients had areas of reversible ischemia. In these 3, 3D whole-heart MRA showed that the proximal course of the left coronary artery was occluded (confirmed with cardiac catheterisation).

CONCLUSIONS

CMR is a good, non-invasive, radiation-free investigation in the post-surgical evaluation of ALCAPA. In referred patients we show that basal, antero-lateral sub-endocardial myocardial fibrosis is a characteristic finding. Furthermore, stress adenosine CMR perfusion, can identify reversible ischemia in this group, and was indicative of left coronary artery occlusion.

Recommendations for cardiovascular magnetic resonance in adults with congenital heart disease from the respective working groups of the European Society of Cardiology

This paper aims to provide information and explanations regarding the clinically relevant options, strengths, and limitations of cardiovascular magnetic resonance (CMR) in relation to adults with congenital heart disease (CHD). Cardiovascular magnetic resonance can provide assessments of anatomical connections, biventricular function, myocardial viability, measurements of flow, angiography, and more, without ionizing radiation. It should be regarded as a necessary facility in a centre specializing in the care of adults with CHD. Also, those using CMR to investigate acquired heart disease should be able to recognize and evaluate previously unsuspected CHD such as septal defects, anomalously connected pulmonary veins, or double-chambered right ventricle. To realize its full potential and to avoid pitfalls, however, CMR of CHD requires training and experience. Appropriate pathophysiological understanding is needed to evaluate cardiovascular function after surgery for tetralogy of Fallot, transposition of the great arteries, and after Fontan operations. For these and other complex CHD, CMR should be undertaken by specialists committed to long-term collaboration with the clinicians and surgeons managing the patients. We provide a table of CMR acquisition protocols in relation to CHD categories as a guide towards appropriate use of this uniquely versatile imaging modality.

Review of Journal of Cardiovascular Magnetic Resonance 2009

There were 56 articles published in the Journal of Cardiovascular Magnetic Resonance in 2009. The editors were impressed with the high quality of the submissions, of which our acceptance rate was about 40%. In accordance with open-access publishing, the articles go on-line as they are accepted with no collating of the articles into sections or special thematic issues. We have therefore chosen to briefly summarise the papers in this article for quick reference for our readers in broad areas of interest, which we feel will be useful to practitioners of cardiovascular magnetic resonance (CMR). In some cases where it is considered useful, the articles are also put into the wider context with a short narrative and recent CMR references. It has been a privilege to serve as the Editor of the JCMR this past year. I hope that you find the open-access system increases wider reading and citation of your papers, and that you will continue to send your quality manuscripts to JCMR for publication.