Gadolinium-enhanced 3-dimensional magnetic resonance angiography of pulmonary blood supply in patients with complex pulmonary stenosis or atresia: comparison with x-ray angiography

Basic Concepts and Insights into Aortopulmonary Collateral Arteries in Congenital Heart Diseases

Aortopulmonary collateral arteries are persistent embryological vessels supplying lung parenchyma in various cardiopulmonary diseases with underlying pulmonary hypoperfusion. Their identification and mapping are important because of associated clinical implications and tendency to affect the surgical outcome. This article describes the embryological development and clinical relevance of aortopulmonary collaterals in various congenital cardiopulmonary conditions, along with the significance for treatment planning. Roles, strength, and shortcomings of the various imaging options and image-guided interventions are discussed, with a focus on presurgical planning and preparation, as well as postsurgical management.

Rightward imbalanced pulmonary perfusion predicts better exercise stroke volume in children after Fallot repair

BACKGROUND

Residual lesions following Fallot repair are primarily pulmonary regurgitation and right ventricular outflow tract obstruction. These lesions may impact exercise tolerance, particularly because of a poor increase in left ventricular stroke volume. Pulmonary perfusion imbalance is also common, but its effect on cardiac adaptation to exercise is not known.

AIM

To assess the association between pulmonary perfusion asymmetry and peak indexed exercise stroke volume (pSVi) in young patients.

METHODS

We retrospectively studied 82 consecutive patients with Fallot repair (mean age 15.2±3.8 years) who underwent echocardiography, four-dimensional flow magnetic resonance imaging and cardiopulmonary testing with pSVi measurement by thoracic bioimpedance. Normal pulmonary flow distribution was defined as right pulmonary artery perfusion between 43 and 61%.

RESULTS

Normal, rightward and leftward flow distributions were found in 52 (63%), 26 (32%) and four (5%) patients, respectively. Independent predictors of pSVi were right pulmonary artery perfusion (β=0.368, 95% confidence interval [CI] 0.188 to 0.548; P=0.0003), right ventricular ejection fraction (β=0.205, 95% CI 0.026 to 0.383; P=0.049), pulmonary regurgitation fraction (β=-0.283, 95% CI -0.495 to -0.072; P=0.006) and Fallot variant with pulmonary atresia (β=-0.213, 95% CI -0.416 to -0.009; P=0.041). The pSVi prediction was similar when the categorical variable right pulmonary artery perfusion>61% was used (β=0.210, 95% CI 0.006 to 0.415; P=0.044).

CONCLUSION

In addition to right ventricular ejection fraction, pulmonary regurgitation fraction and Fallot variant with pulmonary atresia, right pulmonary artery perfusion is a predictor of pSVi, in that rightward imbalanced pulmonary perfusion favours greater pSVi.

CMR and Percutaneous Treatment of Pulmonary Regurgitation: Outreach the Search for the Best Candidate

Performance of cardiovascular magnetic resonance (CMR) in the planning phase of percutaneous pulmonary valve implantation (PPVI) is needed for the accurate delineation of the right ventricular outflow tract (RVOT), coronary anatomy and the quantification of right ventricular (RV) volume overload in patients with significant pulmonary regurgitation (PR). This helps to find the correct timings for the intervention and prevention of PPVI-related complications such as coronary artery compression, device embolization and stent fractures. A defined CMR study protocol should be set for all PPVI candidates to reduce acquisition times and acquire essential sequences that are determinants for PPVI success. For correct RVOT sizing, contrast-free whole-heart sequences, preferably at end-systole, should be adopted in the pediatric population thanks to their high reproducibility and concordance with invasive angiographic data. When CMR is not feasible or contraindicated, cardiac computed tomography (CCT) may be performed for high-resolution cardiac imaging and eventually the acquisition of complementary functional data. The aim of this review is to underline the role of CMR and advanced multimodality imaging in the context of pre-procedural planning of PPVI concerning its current and potential future applications.

Magnetization Transfer BOOST Noncontrast Angiography Improves Pulmonary Vein Imaging in Adults With Congenital Heart Disease

BACKGROUND

Cardiac MRI plays an important role in the diagnosis and follow-up of patients with congenital heart disease (CHD). Gadolinium-based contrast agents are often needed to overcome flow-related and off-resonance artifacts that can impair the quality of conventional noncontrast 3D imaging. As serial imaging is often required in CHD, the development of robust noncontrast 3D MRI techniques is desirable.

PURPOSE

To assess the clinical utility of noncontrast enhanced magnetization transfer and inversion recovery prepared 3D free-breathing sequence (MTC-BOOST) compared to conventional 3D whole heart imaging in patients with CHD.

STUDY TYPE

Prospective, image quality.

POPULATION

A total of 27 adult patients (44% female, mean age 30.9 ± 14.8 years) with CHD.

FIELD STRENGTH/SEQUENCE

A 1.5 T; free-breathing 3D MTC-BOOST sequence.

ASSESSMENT

MTC-BOOST was compared to diaphragmatic navigator-gated, noncontrast T2 prepared 3D whole-heart imaging sequence (T2prep-3DWH) for comparison of vessel dimensions, lumen-to-myocardium contrast ratio (CR), and image quality (vessel wall sharpness and presence and type of artifacts) assessed by two experienced cardiologists on a 5-point scale.

STATISTICAL TESTS

Mann-Whitney test, paired Wilcoxon signed-rank test, Bland-Altman plots. P < 0.05 was considered statistically significant.

RESULTS

MTC-BOOST significantly improved image quality and CR of the right-sided pulmonary veins (PV): (CR: right upper PV 1.06 ± 0.50 vs. 0.58 ± 0.74; right lower PV 1.32 ± 0.38 vs. 0.81 ± 0.73) compared to conventional T2prep-3DWH imaging where the PVs were not visualized in some cases due to off-resonance effects. MTC-BOOST demonstrated resistance to degradation of luminal signal (assessed by CR) secondary to accelerated or turbulent flow conditions. T2prep-3DWH had higher image quality scores than MTC-BOOST for the aorta and coronary arteries; however, great vessel dimensions derived from MTC-BOOST showed excellent agreement with standard T2prep-3DWH imaging.

DATA CONCLUSION

MTC-BOOST allows for improved contrast-free imaging of pulmonary veins and regions characterized by accelerated or turbulent blood flow compared to standard T2prep-3DWH imaging, with excellent agreement of great vessel dimensions.

EVIDENCE LEVEL

1 TECHNICAL EFFICACY: Stage 2.

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.

Cardiovascular Magnetic Resonance in Congenital Heart Disease: Focus on Heart Failure

Over the past decade, cardiovascular magnetic resonance (CMR) has become a mainstream noninvasive imaging tool for assessment of adult and pediatric patients with congenital heart disease. It provides comprehensive anatomic and hemodynamic information that echocardiography and catheterization alone do not provide. Extracardiac anatomy can be delineated with high spatial resolution, intracardiac anatomy can be imaged in multiple planes, and functional assessment can be made accurately and with high reproducibility. In patients with heart failure, CMR provides not only reference standard evaluation of ventricular volumes and function but also information about the possible causes of dysfunction.

SCMR Position Paper (2020) on clinical indications for cardiovascular magnetic resonance

The Society for Cardiovascular Magnetic Resonance (SCMR) last published its comprehensive expert panel report of clinical indications for CMR in 2004. This new Consensus Panel report brings those indications up to date for 2020 and includes the very substantial increase in scanning techniques, clinical applicability and adoption of CMR worldwide. We have used a nearly identical grading system for indications as in 2004 to ensure comparability with the previous report but have added the presence of randomized controlled trials as evidence for level 1 indications. In addition to the text, tables of the consensus indication levels are included for rapid assimilation and illustrative figures of some key techniques are provided.

Factors Influencing Temporal Trends in Pediatric Inpatient Imaging Utilization

BACKGROUND

Concern exists over exponential growth in cardiac imaging in adults, but there is paucity of such data for cardiac imaging trends in pediatric patients. The aims of this study were to determine temporal trends in the use of noninvasive cardiac imaging and compare these with trends in the use of noncardiac imaging and to identify factors influencing those trends using the Pediatric Health Information Service database.

METHODS

Pediatric inpatient encounter data from January 2004 to December 2017 at 35 pediatric hospitals were extracted from the Pediatric Health Information Service database. Temporal imaging utilization trends in cardiac and noncardiac ultrasound or echocardiography, magnetic resonance imaging (MRI), and computed tomography (CT) were assessed using linear mixed-effects models. Models were adjusted for case-mix index, complex chronic conditions, patient age, length of stay, payer source, and cardiac surgical volume.

RESULTS

A total of 5,869,335 encounters over 14 years were analyzed (median encounters per center per year, 11,411; median patient age, 4 years; median length of stay, 3 days). From 2004 to 2017, the rates of pediatric inpatient cardiac and noncardiac ultrasound and MRI increased, whereas the rate of noncardiac CT decreased. Cardiac CT use increased beginning in 2014 (+0.264 cardiac CT encounters per 1,000 encounters per year), surpassing the rate of rise of cardiac MRI. Case-mix index, cardiac surgical volume, and payer source affected the largest number of imaging trends.

CONCLUSIONS

Among pediatric inpatients, utilization of cardiac and noncardiac ultrasound and MRI has steadily increased. Noncardiac CT use declined and cardiac CT use increased after 2014. Factors influencing imaging trends include case-mix index, cardiac surgical volume, and payer source. This study lays a foundation for investigations of imaging-related resource utilization and outcomes among pediatric inpatients.

Tetralogy of Fallot With Pulmonary Atresia: Anatomy, Physiology, Imaging, and Perioperative Management

Tetralogy of Fallot (ToF) with pulmonary atresia (ToF-PA) is a complex congenital heart defect at the extreme end of the spectrum of ToF, with no antegrade flow into the pulmonary arteries. Patients differ with regard to the sources of pulmonary blood flow. In the milder spectrum of disease, there are confluent branch pulmonary arteries fed by ductus arteriosus. In more severe cases, however, the ductus arteriosus is absent, and the sole source of pulmonary blood flow is via major aortopulmonary collateral arteries (MAPCAs). The variability in the origin, size, number, and clinical course of these MAPCAs adds to the complexity of these patients. Currently, the goal of management is to establish pulmonary blood flow from the right ventricle (RV) with RV pressures that are ideally less than half of the systemic pressure to allow for closure of the ventricular septal defect. In the long term, patients with ToF-PA are at higher risk for reinterventions to address pulmonary arterial or RV-pulmonary artery conduit stenosis, progressive aortic root dilation and aortic insufficiency, and late mortality than those with less severe forms of ToF.

mDixon ECG-gated 3-dimensional cardiovascular magnetic resonance angiography in patients with congenital cardiovascular disease

BACKGROUND

Cardiovascular magnetic resonance (CMR) angiography (CMRA) is an important non-invasive imaging tool for congenital heart disease (CHD) and aortopathy patients. The conventional 3D balanced steady-state free precession (bSSFP) sequence is often confounded by imaging artifacts. We sought to compare the respiratory navigated and electrocardiogram (ECG) gated modified Dixon (mDixon) CMRA sequence to conventional non-gated dynamic multi-phase contrast enhanced CMRA (CE-CMRA) and bSSFP across a variety of diagnoses.

METHODS

We included 24 patients with CHD or aortopathy with CMR performed between September 2017 to December 2017. Each patient had undergone CE-CMRA, followed by a bSSFP and mDixon angiogram. Patients with CMR-incompatible implants or contraindications to contrast were excluded. The studies were rated according to image quality at a scale from 1 (poor) to 4 (excellent) based on diagnostic adequacy, artifact burden, vascular border delineation, myocardium-blood pool contrast, and visualization of pulmonary and systemic veins and coronaries. Contrast-to-noise ratio (CNR), signal-to-noise ratio (SNR) and quantitative vascular measurements were compared between the two gated sequences. Bland-Altman plots were generated to compare paired measures.

RESULTS

All scans were diagnostically adequate. Mean (SD) quality scores were 3.4 (0.7) for the mDixon, 3.2 (0.5) for the bSSFP and 3.4 (0.5) for the CE-CMRA. Qualitatively, the intracardiac anatomy and myocardium-blood pool definition were better in the bSSFP; however, mDixon images showed enhanced vessel wall sharpness with less blurring surrounding the anatomical borders distally. Coronary origins were identified in all cases. Pulmonary veins were visualized in 92% of mDixon sequences, 75% of bSSFP and 96% of CE-CMRA. Similarly, neck veins were identified in 92, 83 and 96% respectively. Artifacts prevented vascular measurement in 6/192 (3%) and 4/192 (2%) of total vascular measurements for the mDixon and bSSFP, respectively. However, the size of signal void and field distortion were significantly worse in the latter, particularly for flow and metal induced artifacts.

CONCLUSION

In patients with congenital heart disease, ECG gated mDixon angiography yields high fidelity vascular images including better delineation of head and neck vasculature and pulmonary veins and fewer artifacts than the comparable bSSFP sequence. It should be considered as the preferred strategy for successful CHD imaging in patients with valve stenosis, vascular stents, or metallic implants.

In Vivo Tracking of Tissue Engineered Constructs

To date, the fields of biomaterials science and tissue engineering have shown great promise in creating bioartificial tissues and organs for use in a variety of regenerative medicine applications. With the emergence of new technologies such as additive biomanufacturing and 3D bioprinting, increasingly complex tissue constructs are being fabricated to fulfill the desired patient-specific requirements. Fundamental to the further advancement of this field is the design and development of imaging modalities that can enable visualization of the bioengineered constructs following implantation, at adequate spatial and temporal resolution and high penetration depths. These in vivo tracking techniques should introduce minimum toxicity, disruption, and destruction to treated tissues, while generating clinically relevant signal-to-noise ratios. This article reviews the imaging techniques that are currently being adopted in both research and clinical studies to track tissue engineering scaffolds in vivo, with special attention to 3D bioprinted tissue constructs.

Role of cardiovascular magnetic resonance end-systolic 3D-SSFP sequence in repaired tetralogy of Fallot patients eligible for transcatheter pulmonary valve implantation

To evaluate the usefulness of cardiovascular magnetic resonance (CMR) 3D steady state free precession (SSFP) sequence acquired at end-systole (ES) in repaired Tetralogy of Fallot (rToF) patients eligible for percutaneous pulmonary valve implantation (PPVI). Between 2012 and 2018, 78 rToF patients were selected for pulmonary valve replacement (PVR) according to CMR criteria. CMR protocol included 3D-SSFP sequence used to assess the right ventricle outflow tract (RVOT) diameters at three levels (pulmonary valve remnant, mid-portion, bifurcation) in mid-diastole (MD) or ES, RVOT length and coronary artery anatomy. In 20 rToF patients without indications for PVR (controls), 3D SSFP sequence was acquired at both cardiac phases (MD and ES) to evaluate RVOT dimension throughout the cardiac cycle. Invasive balloon sizing was recorded in patients undergoing PPVI. The 3D-SSFP sequence was performed in MD on 39 patients and in ES on other 39, of whom 26 patients met the criteria for PPVI. The latter was unsuccessful in ten patients (38%), mainly due (80% of cases) to significant size discrepancy at PV remnant and bifurcation levels (p = 0.019 and 0.037 respectively) between the measurements by 3D-SSFP in MD and those by the balloon size in systole. Significant RVOT size difference between MD and ES was present at mid-portion and bifurcation levels in the PVR candidate group, and at all three-levels in the control group (all p < 0.001). ES 3D-SSFP sequence is able to quantify RVOT dilation in rToF patients at its maximum expansion, thus improving selection of PPVI candidates.

Congenital anomalies of the pulmonary arteries: an imaging overview

Congenital pulmonary artery anomalies represent a diverse group of abnormalities, ranging from asymptomatic incidental findings to causes of sudden cardiac death. While some may be recognized in childhood, others may be found incidentally in adulthood. We review the clinical and imaging findings in patients with congenital anomalies of the pulmonary arteries, including valvular and perivavular anomalies as well as abnormal narrowing, course and communications of the pulmonary arteries. We also discuss the role of various imaging modalities in the evaluation of these patients. It is vital to be aware of the key radiologic manifestations and associated haemodynamic consequences in these conditions in order to facilitate accurate diagnosis and prognostic stratification.

Cardiac Magnetic Resonance to Evaluate Percutaneous Pulmonary Valve Implantation in Children and Young Adults

Experience with cardiac magnetic resonance to evaluate coronary arteries in children and young adult patients is limited. Because noninvasive imaging has advantages over coronary angiography, we compared the effectiveness of these techniques in patients who were being considered for percutaneous pulmonary valve implantation. We retrospectively reviewed the cases of 26 patients (mean age, 12.53 ± 4.85 yr; range, 5-25 yr), all of whom had previous right ventricular-to-pulmonary artery homografts. We studied T2-prepared whole-heart images for coronary anatomy, velocity-encoded cine images for ventricular morphology, and function- and time-resolved magnetic resonance angiographic findings. Cardiac catheterization studies included coronary angiography, balloon compression testing, right ventricular outflow tract, and pulmonary artery anatomy. Diagnostic-quality images were obtained in 24 patients (92%), 13 of whom were considered suitable candidates for valve implantation. Two patients (8%) had abnormal coronary artery anatomy that placed them at high risk of coronary artery compression during surgery. Twelve patients underwent successful valve implantation after cardiac magnetic resonance images and catheterization showed no increased risk of compression. We attempted valve implantation in one patient with unsuitable anatomy but ultimately placed a stent in the homograft. Magnetic resonance imaging of coronary arteries is an important noninvasive study that may identify patients who are at high risk of coronary artery compression during percutaneous pulmonary valve implantation, and it may reveal high-risk anatomic variants that can be missed during cardiac catheterization.

Golden ratio stack of spirals for flexible angiographic imaging: Proof of concept in congenital heart disease

PURPOSE

In this study, a golden ratio stack of spiral (GRASS) sequence that used both golden step and golden angle ordering was implemented. The aim was to demonstrate that GRASS acquisitions could be flexibly reconstructed as both cardiac-gated and time-resolved angiograms.

METHODS

Image quality of time-resolved and cardiac-gated reconstructions of the GRASS sequence were compared to 3 conventional stack of spirals (SoS) acquisitions in an in silico model. In 10 patients, the GRASS sequence was compared to conventional breath hold angiography (BH-MRA) in terms of image quality and for vessel measurement. Vessel measurements were also compared to cine images.

RESULTS

In the cardiac-gated in silico model, the image quality of GRASS was superior to regular and golden-angle with regular step SoS approaches. In the time-resolved model, GRASS image quality was comparable to the golden-angle with regular step technique and superior to regular SoS acquisitions. In patients, there was no difference in qualitative image scores between GRASS and BH-MRA, but SNR was lower. There was good agreement in vessel measurements between the GRASS reconstructions and conventional MR techniques (BH-MRA: 29.8 ± 5.6 mm, time-resolved GRASS-MRA: 29.9 ± 5.4 mm, SSFP diastolic: 29.4 ± 5.8 mm, cardiac-gated GRASS-MRA diastolic: 29.5 ± 5.5 mm, P > 0.87).

CONCLUSION

We have demonstrated that the GRASS acquisition enables flexible reconstruction of the same raw data as both time-resolved and cardiac-gated volumes. This may enable better interrogation of anatomy in congenital heart disease.

Routine Cardiac Catheterization Prior to Fontan Operation: Is It a Necessity?

Prior to the Fontan procedure, patients with single ventricle physiology with Glenn shunt are typically referred for cardiac catheterization to assess hemodynamics and potentially provide interventional measures. Currently, echocardiography provides detailed information which together with other non-invasive imaging such as CT scan and MRI may obviate the need for routine cardiac catheterization prior to the Fontan procedure. In this study, we examine the findings in cardiac catheterization in this population to determine: (a) the accuracy of echocardiography in providing adequate information prior to the Fontan procedure, particularly in identifying those in need of per-catheter intervention, and (b) the percentage of patients requiring interventional procedures during cardiac catheterization. We performed a retrospective chart review of echocardiographic and cardiac catheterization data for patients who underwent pre-Fontan cardiac catheterization at our center in the period from 02/01/2008 to 02/28/2017. We aimed to re-examine the necessity of routine cardiac catheterization in all single ventricle patients. This was performed through examining pre-catheterization echocardiography reports and comparing them to findings of the subsequent cardiac catheterization reports. Echocardiography reports were evaluated for accuracy in identifying significant anatomical or hemodynamic findings, which may impact success of Fontan procedure as well as the ability of echocardiography to predict findings important to know prior to the Fontan procedure. In this cohort of 40 children, 3 patients were found to have significant hemodynamic findings through cardiac catheterization which were not previously known by echocardiography. In addition, 28 out of 40 patients (70%) required interventional procedures to address significant abnormalities (systemic to pulmonary arterial collaterals, pulmonary artery stenosis, aortic arch stenosis, etc.). All cases of aortic arch stenosis were detected by echocardiography, however, all patients who required systemic to pulmonary arterial or left SVC embolization were not detected by echocardiography. Furthermore, echocardiography did not detect the need for branch pulmonary artery stenosis in 50% of cases. Cardiac catheterization appears to be an essential part of patient assessment prior to Fontan completion in patients with single ventricle physiology. This current practice may change in the future if a non-invasive screening tool is found to have high positive and negative predictive values in identifying the subset of patients who require potential intervention in pre-Fontan cardiac catheterization.

Complete Preoperative Evaluation of Pulmonary Atresia with Ventricular Septal Defect with Multi-Detector Computed Tomography

Objective

To compare multi-detector computed tomography (MDCT) with cardiac catheterization and transthoracic echocardiography (TTE) in comprehensive evaluation of the global cardiovascular anatomy in patients with pulmonary atresia with ventricular septal defect (PA-VSD).

Methods

The clinical and imaging data of 116 patients with PA-VSD confirmed by surgery were reviewed. Using findings at surgery as the reference standard, data from MDCT, TTE and catheterization were reviewed for assessment of native pulmonary vasculature and intracardiac defects.

Results

MDCT was more accurate than catheterization and TTE in identification of native pulmonary arteries. MDCT is also the most accurate test for delineation of the major aortopulmonary collateral arteries. The inter-modality agreement for evaluation of overriding aorta and VSD were both excellent. In the subgroup with surgical correlation, excellent agreement was found between TTE and surgery, and substantial agreement was also found at MDCT.

Conclusion

MDCT can correctly delineate the native pulmonary vasculatures and intracardiac defects and may be a reliable method for noninvasive assessment of global cardiovascular abnormalities in patients with PA-VSD.

An Overview of Pulmonary Atresia and Major Aortopulmonary Collateral Arteries

Pulmonary atresia with ventricular septal defect and major aortopulmonary collateral arteries (PA/VSD/MAPCAs) is a rare and complex congenital cardiac lesion that has historically carried a poor prognosis. With advancements in surgical management, we have seen an improvement in the outcomes for children affected by this disease. However, this population continues to present challenges due to the complex anatomy and physiology associated with PA/VSD/MAPCA. This summary of material presented during one of the nursing sessions of the 2014 Meeting of the Pediatric Cardiac Intensive Care Society provides an overview for those in cardiac intensive care units who do not have a large experience with this lesion. We will review the anatomy, physiology, surgical approach, postoperative management strategies, and cardiac catheter intervention options for PA/VSD/MAPCAs. We will also discuss recent innovations that may lead to continued improvement in outcomes for this challenging patient population.

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.

Free breathing contrast-enhanced time-resolved magnetic resonance angiography in pediatric and adult congenital heart disease

BACKGROUND

Contrast enhanced magnetic resonance angiography (MRA) is generally performed during a long breath-hold (BH), limiting its utility in infants and small children. This study proposes a free-breathing (FB) time resolved MRA (TRA) technique for use in pediatric and adult congenital heart disease (CHD).

METHODS

A TRA sequence was developed by combining spiral trajectories with sensitivity encoding (SENSE, x4 kx-ky and x2 kz) and partial Fourier (75% in kz). As no temporal data sharing is used, an independent 3D data set was acquired every ~1.3s, with acceptable spatial resolution (~2.3x2.3x2.3 mm). The technique was tested during FB over 50 consecutive volumes. Conventional BH-MRA and FB-TRA data was acquired in 45 adults and children with CHD. We calculated quantitative image quality for both sequences. Diagnostic accuracy was assessed in all patients from both sequences. Additionally, vessel measurements were made at the sinotubular junction (N = 43), proximal descending aorta (N = 43), descending aorta at the level of the diaphragm (N = 43), main pulmonary artery (N = 35), left pulmonary artery (N = 35) and the right pulmonary artery (N = 35). Intra and inter observer variability was assessed in a subset of 10 patients.

RESULTS

BH-MRA had significantly higher homogeneity in non-contrast enhancing tissue (coefficient of variance, P <0.0001), signal-to-noise ratio (P <0.0001), contrast-to-noise ratio (P <0.0001) and relative contrast (P = 0.02) compared to the FB-TRA images. However, homogeneity in the vessels was similar in both techniques (P = 0.52) and edge sharpness was significantly (P <0.0001) higher in FB-TRA compared to BH-MRA. BH-MRA provided overall diagnostic accuracy of 82%, and FB-TRA of 87%, with no statistical difference between the two sequences (P = 0.77). Vessel diameter measurements showed excellent agreement between the two techniques (r = 0.98, P <0.05), with no bias (0.0 mm, P = 0.71), and clinically acceptable limits of agreement (-2.7 to +2.8 mm). Inter and intra observer reproducibility showed good agreement of vessel diameters (r>0.988, P<0.0001), with negligible biases (between -0.2 and +0.1mm) and small limits of agreement (between -2.4 and +2.5mm).

CONCLUSIONS

We have described a FB-TRA technique that is shown to enable accurate diagnosis and vessel measures compared to conventional BH-MRA. This simplifies the MRA technique and will enable angiography to be performed in children and adults whom find breath-holding difficult.

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.

2014 korean guidelines for appropriate utilization of cardiovascular magnetic resonance imaging: a joint report of the korean society of cardiology and the korean society of radiology

Cardiac magnetic resonance (CMR) imaging is now widely used in several fields of cardiovascular disease assessment due to recent technical developments. CMR can give physicians information that cannot be found with other imaging modalities. However, there is no guideline which is suitable for Korean people for the use of CMR. Therefore, we have prepared a Korean guideline for the appropriate utilization of CMR to guide Korean physicians, imaging specialists, medical associates and patients to improve the overall medical system performances. By addressing CMR usage and creating these guidelines we hope to contribute towards the promotion of public health. This guideline is a joint report of the Korean Society of Cardiology and the Korean Society of Radiology.

2014 Korean guidelines for appropriate utilization of cardiovascular magnetic resonance imaging: a joint report of the Korean Society of Cardiology and the Korean Society of Radiology

Cardiac magnetic resonance (CMR) imaging is now widely used in several fields of cardiovascular disease assessment due to recent technical developments. CMR can give physicians information that cannot be found with other imaging modalities. However, there is no guideline which is suitable for Korean people for the use of CMR. Therefore, we have prepared a Korean guideline for the appropriate utilization of CMR to guide Korean physicians, imaging specialists, medical associates and patients to improve the overall medical system performances. By addressing CMR usage and creating these guidelines we hope to contribute towards the promotion of public health. This guideline is a joint report of the Korean Society of Cardiology and the Korean Society of Radiology.

Which cardiovascular magnetic resonance planes and sequences provide accurate measurements of branch pulmonary artery size in children with right ventricular outflow tract obstruction?

Children with right ventricular outflow tract obstructive (RVOTO) lesions require precise quantification of pulmonary artery (PA) size for proper management of branch PA stenosis. We aimed to determine which cardiovascular magnetic resonance (CMR) sequences and planes correlated best with cardiac catheterization and surgical measurements of branch PA size. Fifty-five children with RVOTO lesions and biventricular circulation underwent CMR prior to; either cardiac catheterization (n = 30) or surgery (n = 25) within a 6 month time frame. CMR sequences included axial black blood, axial, coronal oblique and sagittal oblique cine balanced steady-state free precession (bSSFP), and contrast-enhanced magnetic resonance angiography (MRA) with multiplanar reformatting in axial, coronal oblique, sagittal oblique, and cross-sectional planes. Maximal branch PA and stenosis (if present) diameter were measured. Comparisons of PA size on CMR were made to reference methods: (1) catheterization measurements performed in the anteroposterior plane at maximal expansion, and (2) surgical measurement obtained from a maximal diameter sound which could pass through the lumen. The mean differences (Δ) and intra class correlation (ICC) were used to determine agreement between different modalities. CMR branch PA measurements were compared to the corresponding cardiac catheterization measurements in 30 children (7.6 ± 5.6 years). Reformatted MRA showed better agreement for branch PA measurement (ICC > 0.8) than black blood (ICC 0.4-0.6) and cine sequences (ICC 0.6-0.8). Coronal oblique MRA and maximal cross sectional MRA provided the best correlation of right PA (RPA) size with ICC of 0.9 (Δ -0.1 ± 2.1 mm and Δ 0.5 ± 2.1 mm). Maximal cross sectional MRA and sagittal oblique MRA provided the best correlate of left PA (LPA) size (Δ 0.1 ± 2.4 and Δ -0.7 ± 2.4 mm). For stenoses, the best correlations were from coronal oblique MRA of right pulmonary artery (RPA) (Δ -0.2 ± 0.8 mm, ICC 0.9) and sagittal oblique MRA of left pulmonary artery (LPA) (Δ 0.2 ± 1.1 mm, ICC 0.9). CMR PA measurements were compared to surgical measurements in 25 children (5.4 ± 4.8 years). All MRI sequences demonstrated good agreement (ICC > 0.8) with the best (ICC 0.9) from axial cine bSSFP for both RPA and LPA. Maximal cross sectional and angulated oblique reformatted MRA provide the best correlation to catheterization for measurement of branch PA's and stenosis diameter. This is likely due to similar angiographic methods based on reformatting techniques that transect the central axis of the arteries. Axial cine bSSFP CMR was the best surgically measured correlate of PA branch size due to this being a measure of stretched diameter. Knowledge of these differences provides more precise PA measurements and may aid catheter or surgical interventions for RVOTO lesions.

Cardiovascular imaging trends in congenital heart disease: a single center experience

BACKGROUND

Cardiac magnetic resonance imaging (MRI) and CT are available in the recent era at many pediatric cardiac centers.

OBJECTIVE

The aim was to provide a contemporary description of diagnostic imaging trends for definition of congenital heart disease (CHD).

METHODS

Echocardiography, cardiac catheterization, cardiac MRI, and cardiac CT use in patients with congenital heart disease at a single institution was retrospectively recorded (2005-2012). Surgical procedures were recorded. Total and modality-specific rates were estimated by Poisson regression and compared. The median age, studies in patients aged >17 years, and referral diagnosis were tabulated for the last year of review.

RESULTS

An average of 11,940 cardiovascular diagnostic tests was performed annually. The number of total studies, echocardiograms, catheterizations, and surgical procedures, did not change significantly across time. Echocardiography comprised 95% to 97% of all studies performed during each year of review. The use of cardiac MRI (2%) and cardiac CT (1%) increased linearly (P < .001), and the use of diagnostic catheterization decreased (0.7%; P = .0005). The median age was 3 years for echocardiography, 15 years for MRI, 11 years for CT, and 3 years for catheterization. The percentage of patients aged >17 years was 9% for echocardiography, 33% for cardiac MRI, 29% for cardiac CT, and 8% for catheterization. Most patients undergoing CT, MRI, and diagnostic catheterization had moderate or complex CHD.

CONCLUSION

Cardiac CT is used increasingly in the recent era for evaluation of CHD. The increased use of both cardiac CT and cardiac MRI are temporally associated with a decrease in diagnostic cardiac catheterization.

Magnetic resonance angiography vs. angiography in tetralogy of Fallot

AIM

: To determine whether gadolinium-enhanced three-dimensional magnetic resonance angiography can provide a noninvasive alternative to diagnostic catheterization for evaluation of pulmonary artery anatomy in tetralogy of Fallot.

PATIENTS AND METHODS

Thirty-five consecutive patients with tetralogy of Fallot, who attended the cardiology outpatient department between January 2008 and December 2009, were included in the study. There were 21 males and 14 females, with a mean age of 9 ± 4.15 years (range, 3-21 years). Thirty-two patients had tetralogy of Fallot with varying severities of valvular and infundibular stenosis. Three patients had tetralogy of Fallot with pulmonary atresia. All patients underwent both cardiac catheterization with X-ray angiography and 3-dimensional magnetic resonance angiography within one month.

RESULTS

Measurements of right and left pulmonary arteries and aortopulmonary collaterals were equal by both methods. There was a good correlation between magnetic resonance angiography and catheterization measurements of branch pulmonary arteries.

CONCLUSION

Gadolinium-enhanced three-dimensional magnetic resonance angiography can be used as a reliable noninvasive alternative to X-ray cineangiography for delineation of pulmonary arterial anatomy in sick infants and young children, obviating the need for catheterization.

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.

Comparison between proximal thoracic vascular measurements obtained by contrast-enhanced magnetic resonance angiography and by transthoracic echocardiography in infants and children with congenital heart disease

Accurate assessment of the proximal thoracic vasculature in infants and children with congenital heart disease (CHD) is vital for deciding the appropriate surgical or interventional procedure and predicting outcomes. This information usually is obtained by transthoracic echocardiography (TTE). Contrast-enhanced magnetic resonance angiography (CE-MRA) frequently is used to obtain diagnostic data when the image quality by TTE is limited. Calculation of z-scores for measurements obtained by CE-MRA in this population currently is not possible due to the lack of normative data. A reasonable agreement between vessel dimensions by CE-MRA and TTE will allow the use of TTE-based z-scores on measurements from CE-MRA. This study examines the accuracy and agreement of proximal thoracic vascular measurements obtained by CE-MRA versus TTE. Infants and children younger than 3 years with CHD who had a CE-MRA between August 2006 and May 2011 were retrospectively identified. Main and branch pulmonary arteries, ascending aorta, distal transverse arch, and aortic isthmus were measured from CE-MRA and TTE in analogous imaging planes and locations by two investigators blinded to each other. The study enrolled 35 subjects with CHD. The median age was 129 days (range, 0-1077 days), and the median weight was 5.8 kg (range, 2.16-17 kg). The median interval between the two imaging methods was 9 days (range, 0-60 days). Data analysis was performed with 129 of the 210 possible paired measurements. The remaining 81 paired measurements could not be performed due to inaccurate visualization of vessel borders or an unavailable imaging plane from TTE, CE-MRA, or both. The range of vessel sizes measured from 2.8 to 23.4 mm. There was excellent correlation between CE-MRA and TTE (r = 0.94, p < 0.001). The mean difference between the measurements was -0.1 ± 1.2 mm, and the limits of agreement were -2.5 to 2.3 mm. Proximal thoracic vascular measurements obtained by CE-MRA and TTE in infants and children with CHD have a strong correlation. The agreement between these two imaging methods is adequate. Until normative data for vessel size measurements obtained from CE-MRA are available for this population, TTE-based z-scores can be applied to the measurements obtained by CE-MRA.

Inflow-weighted pulmonary perfusion: comparison between dynamic contrast-enhanced MRI versus perfusion scintigraphy in complex pulmonary circulation

BACKGROUND

Due to the different properties of the contrast agents, the lung perfusion maps as measured by 99mTc-labeled macroaggregated albumin perfusion scintigraphy (PS) are not uncommonly discrepant from those measured by dynamic contrast-enhanced MRI (DCE-MRI) using indicator-dilution analysis in complex pulmonary circulation. Since PS offers the pre-capillary perfusion of the first-pass transit, we hypothesized that an inflow-weighted perfusion model of DCE-MRI could simulate the result by PS.

METHODS

22 patients underwent DCE-MRI at 1.5T and also PS. Relative perfusion contributed by the left lung was calculated by PS (PS(L%)), by DCE-MRI using conventional indicator dilution theory for pulmonary blood volume (PBV(L%)) and pulmonary blood flow (PBFL%) and using our proposed inflow-weighted pulmonary blood volume (PBV(iw)(L%)). For PBViw(L%), the optimal upper bound of the inflow-weighted integration range was determined by correlation coefficient analysis.

RESULTS

The time-to-peak of the normal lung parenchyma was the optimal upper bound in the inflow-weighted perfusion model. Using PSL% as a reference, PBV(L%) showed error of 49.24% to -40.37% (intraclass correlation coefficient R(I) = 0.55) and PBF(L%) had error of 34.87% to -27.76% (R(I) = 0.80). With the inflow-weighted model, PBV(iw)(L%) had much less error of 12.28% to -11.20% (R(I) = 0.98) from PS(L%).

CONCLUSIONS

The inflow-weighted DCE-MRI provides relative perfusion maps similar to that by PS. The discrepancy between conventional indicator-dilution and inflow-weighted analysis represents a mixed-flow component in which pathological flow such as shunting or collaterals might have participated.

[Clinical indications for the use of cardiac MRI. By the SIRM Study Group on Cardiac Imaging]

Cardiac magnetic resonance (CMR) is considered an useful method in the evaluation of many cardiac disorders. Based on our experience and available literature, we wrote a document as a guiding tool in the clinical use of CMR. Synthetically we describe different cardiac disorders and express for each one a classification, I to IV, depending on the significance of diagnostic information expected.

Comparison of contrast enhanced magnetic resonance angiography with invasive cardiac catheterization for evaluation of children with pulmonary atresia

Complete assessment of the source of pulmonary blood supply and delineation of the anatomy of pulmonary arteries are essential for the management and prognostic evaluation of pulmonary atresia (PA) patients. Invasive cardiac catheterization is considered the gold standard imaging modality to achieve this. We investigated the role of contrast enhanced magnetic resonance angiography (MRA) to evaluate the pulmonary blood supply and the anatomy of the pulmonary arteries and compared this with cardiac catheterization in children with PA. We studied 20 children with PA. Median age was 2.5 years (range 6 months–13 years). All patients were examined with cardiac catheterization and contrast enhanced MRA, and the results of both modalities were compared. There was a complete agreement between both modalities in the detection of the main pulmonary artery morphology and determination of the confluence state of the central pulmonary arteries. There was an 88% agreement for patency of the ductus arteriosus and 66% for patency of the surgically placed shunt. There was a complete agreement between both techniques on determining the presence of collaterals more than 2.5 mm. Twenty-eight collaterals of less than 2.5 mm were detected only by contrast enhanced MRA. There was a strong correlation between both modalities in measuring the pulmonary arteries and collaterals diameter (P<0.001). Contrast enhanced MRA is a safe and accurate non-invasive technique to evaluate the pulmonary artery morphology and the sources of pulmonary blood supply in children with PA.

Amphiphilic EuDOTA-tetraamide complexes form micelles with enhanced CEST sensitivity

The synthesis and characterization of four new DOTA-tetraamide ligands having variable alkyl chain lengths (C(1), C(12), C(14), and C(16)) and their respective europium (III) complexes are reported. The three EuL complexes having long alkyl chains spontaneously form micelles of variable size. The critical micelle concentration differed for each complex (lower for the C(16) complex than the C(12) complex) while micelle size increased with increasing alkyl chain length. Chemical exchange saturation transfer (CEST) experiments showed that all four Eu(III) complexes display slow-to-intermediate water exchange kinetics. As expected, the CEST signals in these complexes decreased with increasing temperatures due to faster water exchange but, interestingly, the CEST signals for the C(14) and C(16) complexes approached a maximum near 25°C consistent with exchange limited CEST at or near room temperature. The water residence lifetimes obtained by fitting the CEST spectra to the Bloch equations increased in parallel with an increase in alkyl carbon chain-length. By comparisons with the monomethylamide complex, which served as control, the data illustrate that micelle formation serves to slow the rate of water exchange in these systems. The complex having the largest CEST effect per unit Eu(III) concentration (the C(16) analog) had a detection limit of 5.3 μM. This represents an approximate 250-fold increase in sensitivity relative to the monomethylamide control (detection limit ~1.3 mM). These features highlight the potential of using micelle-based systems such as these as paramagnetic chemical exchange saturation transfer (PARACEST) agents for molecular imaging by MRI.

Detection of pulmonary arterial morphology in tetralogy of Fallot with pulmonary atresia by computed tomography: 12 years of experience

Our aim was to evaluate the feasibility of using computed tomography (CT) to define the pulmonary artery anatomy in patients with tetralogy of Fallot and pulmonary atresia (TOF-PA). We retrospectively reviewed 110 patients with TOF-PA between 1995 and 2008. Those who received cardiac catheterization and surgery within 3 months of their CT examinations were enrolled. Based on Dr. Somerville's classification, the pulmonary arterial pattern was determined, including identifiable pulmonary trunk (type I), the presence of both left and right pulmonary arteries without trunk (II), only left or right pulmonary artery present (III), and absent intrapericardial pulmonary arteries (IV). The accuracy of both imaging modalities was evaluated with operation findings as the golden standard. The effective radiation doses and adverse events were also recorded. In the 64 eligible patients (median age, 23 months), CT and catheterization demonstrated accurate pulmonary arterial morphology in 60 (60/64) and 53 (53/64) TOF-PA patients, respectively. Thirty-two of 35 type I patients were correctly identified by CT, whereas 26 were correctly identified by catheterization (p = 0.03). Of the 20 type II TOF-PA patients, 19 were diagnosed by CT, whereas 18 were diagnosed by catheterization. CT and catheterization both successfully defined six type III and three type IV patients. The median calculated radiation doses caused by CT and catheterization were 4.5 and 5.6 mSv, respectively (p > 0.05).

CONCLUSIONS

For patients with TOF-PA, CT could accurately delineate pulmonary arterial morphology with the same level of accuracy as cardiac catheterization. Therefore, CT can be considered a reasonable diagnostic alternative for such patients.

Hypoplastic left heart syndrome: current considerations and expectations

In the recent era, no congenital heart defect has undergone a more dramatic change in diagnostic approach, management, and outcomes than hypoplastic left heart syndrome (HLHS). During this time, survival to the age of 5 years (including Fontan) has ranged from 50% to 69%, but current expectations are that 70% of newborns born today with HLHS may reach adulthood. Although the 3-stage treatment approach to HLHS is now well founded, there is significant variation among centers. In this white paper, we present the current state of the art in our understanding and treatment of HLHS during the stages of care: 1) pre-Stage I: fetal and neonatal assessment and management; 2) Stage I: perioperative care, interstage monitoring, and management strategies; 3) Stage II: surgeries; 4) Stage III: Fontan surgery; and 5) long-term follow-up. Issues surrounding the genetics of HLHS, developmental outcomes, and quality of life are addressed in addition to the many other considerations for caring for this group of complex patients.

The role of cardiovascular magnetic resonance in adults with congenital heart disease

The comprehensive coverage and versatility of cardiovascular magnetic resonance (CMR), providing functional as well as anatomical information, make it an important facility in a center specializing in the care of adults with congenital heart disease. Imaging specialists using CMR to investigate acquired heart disease should also be able to recognize and evaluate previously unsuspected congenital malformations. Conditions that may present or be picked up during imaging in adulthood include atrial septal defect, anomalously connected pulmonary veins, double-chambered right ventricle, congenitally corrected transposition of the great arteries, aortic coarctation, and patent arterial duct. To realize its full potential and to avoid pitfalls, CMR of adults with congenital heart disease requires specific training and experience. Appropriate pathophysiological understanding is needed to evaluate cardiovascular function after surgery for tetralogy of Fallot, after transposition of the great arteries, and after Fontan operations. For these and other more complex cases, CMR should ideally be undertaken by specialists committed to long-term collaboration with the clinicians and surgeons managing the patients in a tertiary referral center.

Imaging congenital heart disease in adults

Transthoracic echocardiography is the first-line modality for cardiovascular imaging in adults with congenital heart disease (ACHD). The windows of access that are possible with transthoracic echocardiography are, however, rarely adequate for all regions of interest. The choice of further imaging depends on the clinical questions that remain to be addressed. The strengths of MRI include comprehensive access and coverage, providing imaging of all parts of the right ventricle, the pulmonary arteries, pulmonary veins and aorta. Cine images and velocity maps are acquired in specifically aligned planes, with stacks of cines or dynamic contrast angiography providing more comprehensive coverage. Tissues can be characterised if necessary, and MRI provides relatively accurate measurements of biventricular function and volume flow. These parameters are important in the assessment and follow-up of adults after repairs for tetralogy of Fallot or transposition of the great arteries and after Fontan operations. The superior spatial resolution and rapid acquisition of CT are invaluable in selected situations, including the visualisation of anomalous coronary or aortopulmonary collateral arteries, the assessment of luminal patency after stenting and imaging in patients with pacemakers. Ionising radiation is, however, a concern in younger patients who may need repeated investigation. Adults with relatively complex conditions should ideally be imaged in a specialist ACHD centre, where dedicated echocardiographic and cardiovascular MRI services are a necessary facility. General radiologists should be aware of the nature and pathophysiology of congenital heart disease, and should be alert for previously undiagnosed cases presenting in adulthood, including cases of atrial septal defect, aortic coarctation, patent ductus arteriosus, double-chambered right ventricle and congenitally corrected transposition.

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.

Preoperative and postoperative MR evaluation of congenital heart disease in children

Cardiovascular magnetic resonance imaging (CMR) plays an important role in the preoperative and postoperative evaluation of congenital heart disease with newer techniques enabling faster and more comprehensive evaluation of the pediatric patient. This article reviews the clinical applications of CMR before and after surgery in the most common congenital heart anomalies in pediatric patients.

Gadolinium-enhanced three-dimensional magnetic resonance angiographic assessment of the pulmonary artery anatomy in cyanotic congenital heart disease with pulmonary stenosis or atresia: comparison with cineangiography

Pulmonary stenosis (PS) or pulmonary atresia (PA) is an important component of complex cyanotic congenital heart disease, especially in tetralogy of Fallot or lesions with ventricular septal defect (VSD)-PS physiology. Management strategy in these patients depends on accurate assessment of PAs and identification of all sources of pulmonary blood flow. X-ray cineangiography is the "gold standard" for this purpose, but it has the inherent risks of an invasive procedure. Gadolinium-enhanced three-dimensional magnetic resonance angiography (Gd-MRA) has been shown to noninvasively and accurately evaluate various lesions of the vascular system. This study was undertaken to evaluate the accuracy of Gd-MRA compared with cineangiography in the evaluation of pulmonary anatomy. Nineteen patients having complex cyanotic heart disease with PS or PA were included in the study. All patients underwent Gd-MRA and cineangiography. Catheterisation and MRA findings regarding the anatomic variable of interest were analysed for agreement by Bland-Altman analysis. There was total agreement between the two modalities in the delineation of confluent PAs. McGoon's ratio and the Nakata index, which are standard measures of the adequacy of PA size, also showed excellent agreement between the two modalities. MRA was able to delineate all aorto-pulmonary collaterals in the setting of PA. MRA can delineate all sources of pulmonary blood supply in cyanotic congenital heart disease with PS and/or PA as well as provide accurate assessment of PA size for planning corrective surgery.