SCMR expert consensus statement for cardiovascular magnetic resonance of acquired and non-structural pediatric heart disease.

Cardiovascular magnetic resonance (CMR) is widely used for diagnostic imaging in the pediatric population. In addition to structural congenital heart disease (CHD), for which published guidelines are available, CMR is also performed for non-structural pediatric heart disease, for which guidelines are not available. This article provides guidelines for the performance and reporting of CMR in the pediatric population for non-structural ("non-congenital") heart disease, including cardiomyopathies, myocarditis, Kawasaki disease and systemic vasculitides, cardiac tumors, pericardial disease, pulmonary hypertension, heart transplant, and aortopathies. Given important differences in disease pathophysiology and clinical manifestations as well as unique technical challenges related to body size, heart rate, and sedation needs, these guidelines focus on optimization of the CMR examination in infants and children compared to adults. Disease states are discussed, including the goals of CMR examination, disease-specific protocols, and limitations and pitfalls, as well as newer techniques that remain under development.

Accuracy of Cardiac Magnetic Resonance Imaging in Diagnosing Pediatric Cardiac Masses: A Multicenter Study.

BACKGROUND: After diagnosis of a cardiac mass, clinicians must weigh the benefits and risks of ascertaining a tissue diagnosis. Limited data are available on the accuracy of previously developed noninvasive pediatric cardiac magnetic resonance (CMR)-based diagnostic criteria. OBJECTIVES: The goals of this study were to: 1) evaluate the CMR characteristics of pediatric cardiac masses from a large international cohort; 2) test the accuracy of previously developed CMR-based diagnostic criteria; and 3) expand diagnostic criteria using new information. METHODS: CMR studies (children 0-18 years of age) with confirmatory histological and/or genetic diagnosis were analyzed by 2 reviewers, without knowledge of prior diagnosis. Diagnostic accuracy was graded as: 1) single correct diagnosis; 2) correct diagnosis among a differential; or 3) incorrect diagnosis. RESULTS: Of 213 cases, 174 (82%) had diagnoses that were represented in the previously published diagnostic criteria. In 70% of 174 cases, both reviewers achieved a single correct diagnosis (94% of fibromas, 71% of rhabdomyomas, and 50% of myxomas). When ≤2 differential diagnoses were included, both reviewers reached a correct diagnosis in 86% of cases. Of 29 malignant tumors, both reviewers indicated malignancy as a single diagnosis in 52% of cases. Including ≤2 differential diagnoses, both reviewers indicated malignancy in 83% of cases. Of 6 CMR sequences examined, acquisition of first-pass perfusion and late gadolinium enhancement were independently associated with a higher likelihood of a single correct diagnosis. CONCLUSIONS: CMR of cardiac masses in children leads to an accurate diagnosis in most cases. A comprehensive imaging protocol is associated with higher diagnostic accuracy.

Pitfalls in surgical repair of Fallot's tetralogy: The "ventricular subaortic pouch".

Fallot-type ventricular septal defect (VSD) is characterized by anterior malalignment of the outlet septum with variable degree of aortic dextroposition. Correct identification of the borders of the defect is crucial to achieve an optimal surgical repair. We describe a particular postsurgical lesion, identified by cardiac magnetic resonance and cardiac computed tomography, which results from an improper surgical closure technique of anterior malaligned VSD. Based on its anatomical features we defined this entity "subaortic pouch." A comprehensive description of this defect is here provided along with an in-depth analysis of the proper operative technique for Fallot-type VSD repair.

Impact of right atrium dimension on adverse outcome after pulmonary valve replacement in repaired Tetralogy of Fallot patients.

The hemodynamic impact of residual pulmonary regurgitation (PR) in repaired Tetralogy of Fallot (rTOF) has been well demonstrated. However, markers driving the decision making process to indicate the ideal timing of pulmonary valve replacement (PVR) are still uncertain. Furthermore, very few studies have included the right atrium (RA) dilatation as a preoperative risk factor for post-PVR clinical adverse outcome. The aim of this study was to investigate the impact of pre-PVR right atrial dilation on adverse outcomes in rTOF. We retrospectively reviewed from our CMR database all rTOF patients who underwent CMR study before and after PVR. Detailed clinical and surgical history were collected, in addition to imaging data. The composite primary and secondary post-PVR end points were also recorded. The study cohort consisted of 41 patients (mean age at PVR repair 27.4 ± 10 years). As expected, end-diastolic and end-systolic right ventricle (RV) volumes significantly decreased after PVR (p < 0.001). The RV reverse remodeling, defined by ΔRVEDVi and ΔRVESVi, was associated with both pre-PVR RVEDVi and RVESVi. The higher the pre-PVR RV volumes, more the RV reverse remodeling will be obtained post-surgery. Patients who experienced an adverse outcome were older at pre-PVR, they had a higher Nt-ProBNP, worse VO2/kg/min, more significant tricuspid regurgitation and more dilated RA. The association with the RA dilatation persists and becomes even more significant if we exclude patients who had tricuspid repair beside RVOT surgical reconstruction. Besides RV volumes and function, RA dimensions may play a pivotal role in the decision making of TOF patients.

Functional Magnetic Resonance Imaging in the Evaluation of the Elastic Properties of Ascending Aortic Aneurysm.

OBJECTIVE: To evaluate the aortic wall elasticity using the maximal rate of systolic distension (MRSD) and maximal rate of diastolic recoil (MRDR) and their correlation with the aortic size index (ASI). METHODS: Forty-eight patients with thoracic aortic aneurysm were enrolled in this study. A standard magnetic resonance imaging (MRI) protocol was used to calculate MRSD and MRDR. Both MRSD and MRDR were expressed as percentile of maximal area/10-3 sec. ASI (maximal aortic diameter/body surface area) was calculated. A correlation between MRSD, MRDR, ASI, and the patient's age was performed using regression plot. RESULTS: A significant correlation between MRSD (t=-4,36; r2=0.29; P≤0.0001), MRDR (t=3.92; r2=0.25; P=0.0003), and ASI (25±4.33 mm/m2; range 15,48-35,14 mm/m2) is observed. As ASI increases, aortic MRSD and MRDR decrease. Such inverse correlation between MRSD, MRDR, and ASI indicates increased stiffness of the ascending aorta. A significant correlation between the patient's age and the decrease in MRSD and MRDR is observed. CONCLUSION: MRSD and MRDR are significantly correlated with ASI and the patient's age. They seem to describe properly the increasing stiffness of aortas. These two new indexes provide a promising, accessible, and reproducible approach to evaluate the biomechanical property of the aorta.

Functional magnetic resonance imaging in the evaluation of the elastic properties of ascending aortic aneurysm

Abstract Objective: To evaluate the aortic wall elasticity using the maximal rate of systolic distension (MRSD) and maximal rate of diastolic recoil (MRDR) and their correlation with the aortic size index (ASI). Methods: Forty-eight patients with thoracic aortic aneurysm were enrolled in this study. A standard magnetic resonance imaging (MRI) protocol was used to calculate MRSD and MRDR. Both MRSD and MRDR were expressed as percentile of maximal area/10-3 sec. ASI (maximal aortic diameter/body surface area) was calculated. A correlation between MRSD, MRDR, ASI, and the patient's age was performed using regression plot. Results: A significant correlation between MRSD (t=-4,36; r2=0.29; P≤0.0001), MRDR (t=3.92; r2=0.25; P=0.0003), and ASI (25±4.33 mm/m2; range 15,48-35,14 mm/m2) is observed. As ASI increases, aortic MRSD and MRDR decrease. Such inverse correlation between MRSD, MRDR, and ASI indicates increased stiffness of the ascending aorta. A significant correlation between the patient's age and the decrease in MRSD and MRDR is observed. Conclusion: MRSD and MRDR are significantly correlated with ASI and the patient's age. They seem to describe properly the increasing stiffness of aortas. These two new indexes provide a promising, accessible, and reproducible approach to evaluate the biomechanical property of the aorta.

Lung ultrasound reclassification of chest X-ray data after pediatric cardiac surgery.

INTRODUCTION: Lung ultrasound is gaining consensus for the diagnosis of some pulmonary conditions. Pulmonary complications are common in pediatric cardiac surgery. However, its use remains limited in this setting. Our aim was to test the feasibility of lung ultrasound following pediatric cardiac surgery and to compare lung ultrasound and chest X-ray findings, assessing whether lung ultrasound may provide additional information. METHODS: One hundred and thirty-eight lung ultrasound examinations were performed in 79 children (median age 9.3 months) at different time points after surgery. For each hemithorax, 3 areas (anterior/lateral/posterior) have been evaluated in the upper and lower halves of the chest (for a total of 6 scanning sites per side). Pleural effusion, atelectasis, and the number of B-lines were investigated. RESULTS: Lung ultrasound was feasible in all cases in at least 1 of the 3 areas. Feasibility was different for the lateral, posterior, and anterior areas (100%, 90%, and 78%, respectively). The posterior areas were more sensitive than anterior and lateral ones in the diagnosis of effusion/atelectasis. In 81 cases, lung ultrasound allowed reclassification of chest X-ray findings, including 40 new diagnoses (diagnosis of effusion/atelectasis with negative chest X-ray reports) and 41 changes in diagnosis (effusions reclassified as atelectasis/severe congestion or vice versa). Although new diagnosis of small-to-moderate effusion/atelectasis was of limited clinical value, in 29 cases the new diagnosis changed the therapeutic approach. CONCLUSION: Lung ultrasound is feasible and accurate for the diagnosis of common pulmonary conditions after pediatric cardiac surgery, allowing reclassification of chest X-ray findings in a significant number of patients.

Clinical recommendations of cardiac magnetic resonance, Part II: inflammatory and congenital heart disease, cardiomyopathies and cardiac tumors: a position paper of the working group 'Applicazioni della Risonanza Magnetica' of the Italian Society of Cardiology.

The current document was developed by the working group on the 'application of cardiac magnetic resonance' of the Italian Society of Cardiology to provide a perspective on the current state of technical advances and clinical cardiac magnetic resonance applications and to inform cardiologists how to implement their clinical and diagnostic pathway with the introduction of this technique in the clinical practice. Appropriateness criteria were defined using a score system: score 1-3 = inappropriate (test is not generally acceptable and is not a reasonable approach for the indication), score 4-6 = uncertain (test may be generally acceptable and may be a reasonable approach for the indication but more research and/or patient information is needed to classify the indication definitively) and score 7-9 = appropriate (test is generally acceptable and is a reasonable approach for the indication).

Usefulness of Combined Functional Assessment by Cardiac Magnetic Resonance and Tissue Characterization Versus Task Force Criteria for Diagnosis of Arrhythmogenic Right Ventricular Cardiomyopathy.

Current task force criteria (TFC) of cardiac magnetic resonance (CMR) for the diagnosis of arrhythmogenic right ventricular cardiomyopathy (ARVC/D) were generated by comparing probands (mean age of 44 years) to healthy participants of the multi-ethnic study of atherosclerosis (mean age of 60 years). These age differences may be a selection bias because right ventricular end-diastolic volume index decreases 4.6% per decade. Moreover, fat infiltration and late gadolinium enhancement were not included. We evaluated the diagnostic accuracy of TFC using the same methodology used by the task force but comparing probands and age- and gender-matched healthy controls and considering also other morphofunctional and tissue abnormalities detected by CMR. Forty-seven probands with previous diagnosis of ARVC/D (excluding probands if CMR was used for diagnosis) were compared with 216 age- and gender-matched healthy controls. TFC had optimal specificity (100%) but poor sensitivity (20% for major and 13% for minor criteria). The presence of any pre- and post-contrast signal abnormalities had 100% specificity and 81% sensitivity. The best diagnostic accuracy (98%) was achieved by the combined evaluation of any right ventricular wall motion abnormality (excluding hypokinesia) with any signal abnormality (including left ventricular fat infiltration and late gadolinium enhancement) yielding a 100% specificity and 96% sensitivity. Left ventricular was involved in 45% of the probands. Current TFC for CMR presented optimal specificity but poor sensitivity to identify patient with ARVC/D. Signal and wall motion parameters of CMR should be considered together to achieve the best diagnostic accuracy for the diagnosis of ARVC/D.

Role of stress echocardiography in operated fallot: feasibility and detection of right ventricular response.

BACKGROUND: Patients with repaired tetralogy of Fallot often present residual hemodynamic abnormalities leading to right ventricular (RV) burden. Semisupine exercise echocardiography (Ex-Echo) is a validated method for diagnosis and prognosis in ischemic and valvular heart diseases and has potential for the evaluation of RV burden, pressure, and function. The aims of this study were to assess the effect of exercise on the right ventricle in adults with repaired tetralogy of Fallot and to identify factors associated with decreased RV function at peak exercise in an observational study. METHODS: A total of 128 patients with repaired tetralogy of Fallot referred to an outpatient congenital heart disease unit were evaluated by Ex-Echo and conventional clinical and diagnostic examinations (i.e., electrocardiography, transthoracic echocardiography, cardiovascular magnetic resonance, cardiopulmonary exercise testing, and N-terminal pro-brain natriuretic peptide assay). The following Ex-Echo parameters were measured at rest and at peak exercise: tricuspid annular plane systolic excursion, RV pressure, and RV fractional area change (FAC). RESULTS: Interpretable images for RV FAC analysis were obtained in 123 of 128 patients. In 91 of 128 with detectable tricuspid valve regurgitation, RV systolic pressure during exercise was evaluated. According to positive or negative RV FAC variation during exercise, 74 patients were respectively defined as "responders" on stress echocardiography and 49 as "nonresponders"; the median percentage change between rest and stress was 13.8% (interquartile range, 5.9% to 26.9%) in responders and -13.5% (interquartile range, -25.4% to -7.4%) in nonresponders. Systolic RV systolic pressure increased in a similar manner in the two groups (65 ± 36% in responders vs 59 ± 39% in nonresponders, P = .45). Tricuspid annular plane systolic excursion increased significantly during peak exercise in responders from 17.2 ± 3.4 mm at rest to 19.7 ± 4.3 mm (P < .0001) but did not in nonresponders (from 16.9 ± 4.7 to 18.1 ± 4.6 mm, P = .20). Left ventricular end-diastolic volume at rest and left ventricular ejection fraction < 50% were related to the lack of increased RV FAC on exercise. CONCLUSIONS: Ex-Echo is feasible in patients with repaired tetralogy of Fallot and allows the integrated assessment of variation in RV systolic pressure, area, and function during exercise, which usefully complement more conventional indices of hemodynamic burden in these patients. Longitudinal follow-up is needed to better delineate the prognostic value of the results of Ex-Echo.

Age-dependent changes in elastic properties of thoracic aorta evaluated by magnetic resonance in normal subjects.

OBJECTIVES: Aortic stiffness is an independent cardiovascular risk factor. Cardiac magnetic resonance (CMR) allows evaluation of aortic elastic properties by different indexes such as distensibility, the maximum rate of systolic distension (MRSD) and pulse wave velocity (PWV). We sought to define age-dependent changes of indexes of elastic properties of the thoracic aorta in healthy subjects. METHODS: We enrolled 85 healthy subjects (53 males) free of overt cardiovascular disease subdivided into 6 classes of age (from 15 to >60 years). Distensibility, MRSD and PWV were measured by the analysis of CMR images acquired using a 1.5 T clinical scanner. RESULTS: MRSD and distensibility decreased progressively through the classes of age (P < 0.001) after an initial plateau between 20 and 30 years in males and 15 and 20 years in females. Pulse wave velocity increased progressively with the age (P < 0.001). Distensibility was related to body mass index (P = 0.002), surface area (P < 0.005), weight (P = 0.005) and to left ventricular parameters such as mass index (P < 0.001) and end-diastolic volume index (P = 0.002). MRSD was related to end-diastolic volume index (P < 0.001) but not to body parameters. PWV was not related to body and ventricular parameters. CONCLUSIONS: This study confirmed that physiological ageing is associated with a progressive impairment of the elastic properties of the aortic wall. Results of this study may be useful for the early identification of subjects with impaired aortic wall properties providing referral values of elasticity indexes assessed by CMR in different classes of age.

The role of cardiovascular magnetic resonance in candidates for Fontan operation: proposal of a new algorithm.

BACKGROUND: To propose a new diagnostic algorithm for candidates for Fontan and identify those who can skip cardiac catheterization (CC). METHODS: Forty-four candidates for Fontan (median age 4.8 years, range: 2-29 years) were prospectively evaluated by trans-thoracic echocardiography (TTE), Cardiovascular magnetic resonance (CMR) and CC. Before CC, according to clinical, echo and CMR findings, patients were divided in two groups: Group I comprised 18 patients deemed suitable for Fontan without requiring CC; group II comprised 26 patients indicated for CC either in order to detect more details, or for interventional procedures. RESULTS: In Group I ("CC not required") no unexpected new information affecting surgical planning was provided by CC. Conversely, in Group II new information was provided by CC in three patients (0 vs 11.5%, p = 0.35) and in six an interventional procedure was performed. During CC, minor complications occurred in one patient from Group I and in three from Group II (6 vs 14%, p = 0.7). Radiation Dose-Area product was similar in the two groups (Median 20 Gycm(2), range: 5-40 vs 26.5 Gycm(2), range: 9-270 p = 0.37). All 18 Group I patients and 19 Group II patients underwent a total cavo-pulmonary anastomosis; in the remaining seven group II patients, four were excluded from Fontan; two are awaiting Fontan; one refused the intervention. CONCLUSION: In this paper we propose a new diagnostic algorithm in a pre-Fontan setting. An accurate non-invasive evaluation comprising TTE and CMR could select patients who can skip CC.

Characterization of cardiac tumors in children by cardiovascular magnetic resonance imaging: a multicenter experience.

OBJECTIVES: The aim of this study was to report the results of an international multicenter experience of cardiac magnetic resonance imaging (MRI) evaluation of cardiac tumors in children, each with histology correlation or a diagnosis of tuberous sclerosis, and to determine which characteristics are predictive of tumor type. BACKGROUND: Individual centers have relatively little experience with diagnostic imaging of cardiac tumors in children, because of their low prevalence. The accuracy of cardiac MRI diagnosis on the basis of a pre-defined set of criteria has not been tested. METHODS: An international group of pediatric cardiac imaging centers was solicited for case contribution. Inclusion criteria comprised: 1) age at diagnosis ≤18 years; 2) cardiac MRI evaluation of cardiac tumor; and 3) histologic diagnosis or diagnosis of tuberous sclerosis. Data from the cardiac MRI images were analyzed for mass characteristics. On the basis of pre-defined cardiac MRI criteria derived from published data, 3 blinded investigators determined tumor type, and their consensus diagnoses were compared with histologic diagnoses. RESULTS: Cases (n = 78) submitted from 15 centers in 4 countries had the following diagnoses: fibroma (n = 30), rhabdomyoma (n = 14), malignant tumor (n = 12), hemangioma (n = 9), thrombus (n = 4), myxoma (n = 3), teratoma (n = 2), and paraganglioma, pericardial cyst, Purkinje cell tumor, and papillary fibroelastoma (n = 1, each). Reviewers who were blinded to the histologic diagnoses correctly diagnosed 97% of the cases but included a differential diagnosis in 42%. Better image quality grade and more complete examination were associated with higher diagnostic accuracy. CONCLUSIONS: Cardiac MRI can predict the likely tumor type in the majority of children with a cardiac mass. A comprehensive imaging protocol is essential for accurate diagnosis. However, histologic diagnosis remains the gold standard, and in some cases malignancy cannot be definitively excluded on the basis of cardiac MRI images alone.