3D advanced imaging overlay with rapid registration in CHD to reduce radiation and assist cardiac catheterisation interventions

Normative Computed Tomography Angiography Values of the Aortic Root, Aorta and Aortic arch in Children

Purpose

Normative values for intracardiac and extracardiac vascular structures help in understanding normal growth and changes over time in children; this normative data are not currently available for ECG-gated Computed Tomography Angiography (CTA). We sought to establish ECG-gated CTA derived normative values for the aortic root, aorta and aortic arch in children.

Methods and Results

Aortic root, ascending aorta, aortic arch, and descending aorta were measured in systole and diastole in 100 subjects who had ECG-gated CTA at our center between January 2015 through December 2020 and met our inclusion criteria. The allometric exponent (AE) for each parameter was derived, and the parameter/body surface areaAE (BSAAE) was established using the previously described methods. Using this data, normalized mean, cross-sectional area, and standard deviation were calculated. Z-score curves were plotted in relation to the BSA for all measurements.

Conclusion

Our study reports systolic and diastolic ECG-gated CTA Z-scores along with normative curves in relation to BSA for the aortic root, aorta and aortic arch in children.

Normative computed tomography angiography values of the main and branch pulmonary arteries in children

Non-invasive cardiac imaging like echocardiogram, cardiac magnetic resonance imaging (CMR), and computed tomography angiography (CTA) play a key role in the diagnosis, aid in management and follow-up of congenital heart disease patients. Normative data for intracardiac and extracardiac vascular structures in children are currently available for echocardiogram, CMR, and non-gated CTA. We sought to establish systolic and diastolic normative data for main and branch pulmonary arteries in children using electrocardiogram (ECG)-gated CTA. Diameters and cross-sectional areas of the main and branch pulmonary arteries were measured in systole and diastole based on the aortic valve position (open versus closed) in 100 subjects who had ECG-gated cardiac CTA at our center between January 2015 through December 2020 and met our inclusion criteria. The allometric exponent (AE) for each parameter was derived, and the parameter/body surface area (BSAAE) was established using the previously described methods. A total of 100 children aged 0-18 years were analyzed; mean age was 5.3 years (SD, 6.1 years). Z-score curves were plotted in relation to the BSA for the mean, maximum, and minimum diameters and cross-sectional area of the main and branch pulmonary arteries for systole and diastole.   Conclusion: We report systolic and diastolic mean, maximum, and minimum diameters and cross-sectional areas along with Z-scores and normative curves for the main and branch pulmonary arteries in children derived using ECG-gated cardiac CTA. We believe our results can help identify abnormally sized main and branch pulmonary arteries. What is Known: • Normative data for intracardiac and extracardiac vascular structures in the pediatric population are available for echocardiography, cardiac MRI and non-ECG gated CTA. • Z-scores with standard deviations are commonly used in children, but SDs are not constant across body sizes due to heteroscedasticity. What is New: • Allometric exponent was derived for each parameter and the parameter/body surface area (BSA) was established. • This is the first ECG-gated CTA study to provide normative en face systolic, diastolic diameters and cross-sectional areas along with Z-scores and normative curves for the main and branch pulmonary arteries in children.

Novel Techniques in Imaging Congenital Heart Disease: JACC Scientific Statement

Recent years have witnessed exponential growth in cardiac imaging technologies, allowing better visualization of complex cardiac anatomy and improved assessment of physiology. These advances have become increasingly important as more complex surgical and catheter-based procedures are evolving to address the needs of a growing congenital heart disease population. This state-of-the-art review presents advances in echocardiography, cardiac magnetic resonance, cardiac computed tomography, invasive angiography, 3-dimensional modeling, and digital twin technology. The paper also highlights the integration of artificial intelligence with imaging technology. While some techniques are in their infancy and need further refinement, others have found their way into clinical workflow at well-resourced centers. Studies to evaluate the clinical value and cost-effectiveness of these techniques are needed. For techniques that enhance the value of care for congenital heart disease patients, resources will need to be allocated for education and training to promote widespread implementation.

Cardiac tomography-echocardiography imaging fusion: a new approach to congenital heart disease

INTRODUCTION AND OBJECTIVES

Diagnosis, management, and surgical decision-making in children and adults with congenital heart disease are largely based on echocardiography findings. A recent development in cardiac imaging is fusion of different imaging modalities. Our objective was to evaluate the feasibility of computed tomography (CT) and 3-dimensional (3D) transthoracic echocardiography (TTE) fusion in children and adults with congenital heart disease.

METHODS

We prospectively included 14 patients, 13 of whom had congenital heart disease, and who underwent both CT and 3D TTE as part of their usual follow-up. We described the steps required to complete the fusion process (alignment, landmarks, and superimposition), navigation, and image evaluation.

RESULTS

Median age was 9.5 [2.7-15.7] years, 57% were male, and median body surface area was 0.9 m² [0.6-1.7]. Congenital heart disease was classified as simple (n=4, 29%), moderate (n=4, 29%), or complex (n=6, 42%). 3D TTE-CT fusion was successful in all patients. Median total time to complete the fusion process was 735 [628-1163] seconds, with no significant difference according to the degree of complexity of the defects. Landmarks were significantly modified in complex congenital heart disease.

CONCLUSIONS

We established the feasibility and accuracy of 3D TTE-CT fusion in a population of children and adults with a variety of congenital heart diseases. The simultaneous visualization of many intracardiac structures may help to understand the anatomical features of congenital heart disease without limitations regarding age, weight, or complexity of the congenital defects.

Transcatheter Device Therapy and the Integration of Advanced Imaging in Congenital Heart Disease

Transcatheter device intervention is now offered as first line therapy for many congenital heart defects (CHD) which were traditionally treated with cardiac surgery. While off-label use of devices is common and appropriate, a growing number of devices are now specifically designed and approved for use in CHD. Advanced imaging is now an integral part of interventional procedures including pre-procedure planning, intra-procedural guidance, and post-procedure monitoring. There is robust societal and industrial support for research and development of CHD-specific devices, and the regulatory framework at the national and international level is patient friendly. It is against this backdrop that we review transcatheter implantable devices for CHD, the role and integration of advanced imaging, and explore the current regulatory framework for device approval.

Role of Cross-Sectional Imaging in Pediatric Interventional Cardiac Catheterization

Management of congenital heart disease (CHD) has recently increased utilization of cross-sectional imaging to plan percutaneous interventions. Cardiac computed tomography (CT) and cardiac magnetic resonance (CMR) imaging have become indispensable tools for pre-procedural planning prior to intervention in the pediatric cardiac catheterization lab. In this article, we review several common indications for referral and the impact of cross-sectional imaging on procedural planning, success, and patient surveillance.

Application of Vessel Navigator™ fusion imaging software in a complex transcatheter palliation of Tetralogy of Fallot with pulmonary atresia

Extreme pulmonary artery hypoplasia in cyanotic malformations precludes palliative surgeries. When aortopulmonary collaterals (APC) in such patients are also hypoplastic, their unifocalization to create a neopulmonary vasculature is also hampered. Stent angioplasty of the outflow or collateral arteries may reduce hypoxia but is challenging in tortuous and atretic tracts. Fusion imaging overlays anatomical data from computed tomography during adult structural interventions, but its use is not often reported in young children with complex cyanotic malformations. This report shows utility of fusion imaging in pulmonary atresia with extremely hypoplastic pulmonary arteries and stenotic APC to guide stenting of outflow tract and collaterals.

Pre-procedural CT imaging aids neonatal PDA stenting for ductal-dependent pulmonary blood flow with reduction in overall procedural morbidity

Patent ductus arteriosus stenting for ductal-dependent pulmonary blood flow is a technically challenging neonatal procedure to maintain a stable pulmonary circulation. Pre-procedural computed tomography imaging aids in outlining ductal origin, insertion, size, course and curvature. Computed tomography imaging may add value to procedural outcomes and reduce overall procedural morbidity in neonatal patent ductus arteriosus stenting. We conducted a single centre retrospective chart review of neonates with ductal-dependent pulmonary blood flow who underwent patent ductus arteriosus stenting between January 1, 2014 and June 31, 2020. We compared patients variables between patients who underwent pre-procedural computed tomography imaging to those who did not. A total of 64 patients were referred for patent ductus arteriosus stenting with 33 (52%) obtaining pre-procedural computed tomography imaging. Average age [19 days; range 1-242 days (p = 0.85)] and weight [3.3 kg (range 2.2-6.0 kg; p = 0.19)] was not significantly different between the groups. A diagnosis of pulmonary atresia was made in 42 out of 64 (66%) patients prior to patent ductus arteriosus stenting. The cohort with pre-intervention computed tomography imaging had a significant reduction in the total number of access sites (1.2 versus 1.5; p = 0.03), contrast needed (5.9 versus 8.2 ml/kg; p = 0.008), fluoroscopy (20.7 versus 38.8 minutes; p = 0.02) and procedural time (83.4-128.4 minutes; p = 0.002) for the intervention. There was no significant difference in radiation burden between the groups (p = 0.35). Pre-procedural computed tomography imaging adds value by aiding interventional planning for neonatal patent ductus arteriosus stenting. A statistically significant reduction in the number of access sites, contrast exposure, as well as fluoroscopic and procedural time was noted without significantly increasing the cumulative radiation burden.

Robotics, imaging, and artificial intelligence in the catheterisation laboratory

The catheterisation laboratory today combines diagnosis and therapeutics, through various imaging modalities and a prolific list of interventional tools, led by balloons and stents. In this review, we focus primarily on advances in image-based coronary interventions. The X-ray images that are the primary modality for diagnosis and interventions are combined with novel tools for visualisation and display, including multi-imaging co-registration modalities with three- and four-dimensional presentations. Interpretation of the physiologic significance of coronary stenosis based on prior angiographic images is being explored and implemented. Major efforts to reduce X-ray exposure to the staff and the patients, using computer-based algorithms for image processing, and novel methods to limit the radiation spread are being explored. The use of artificial intelligence (AI) and machine learning for better patient care requires attention to universal methods for sharing and combining large data sets and for allowing interpretation and analysis of large cohorts of patients. Barriers to data sharing using integrated and universal protocols should be overcome to allow these methods to become widely applicable. Robotic catheterisation takes the physician away from the ionising radiation spot, enables coronary angioplasty and stenting without compromising safety, and may allow increased precision. Remote coronary procedures over the internet, that have been explored in virtual and animal studies and already applied to patients in a small pilot study, open possibilities for sharing experience across the world without travelling. Application of those technologies to neurovascular, and particularly stroke interventions, may be very timely in view of the need for expert neuro-interventionalists located mostly in central areas.

Fick versus flow: a real-time invasive cardiovascular magnetic resonance (iCMR) reproducibility study

BACKGROUND

Cardiac catheterization and cardiovascular magnetic resonance (CMR) imaging have distinct diagnostic roles in the congenital heart disease (CHD) population. Invasive CMR (iCMR) allows for a more thorough assessment of cardiac hemodynamics at the same time under the same conditions. It is assumed but not proven that iCMR gives an incremental value by providing more accurate flow quantification.

METHODS

Subjects with CHD underwent real-time 1.5 T iCMR using a passive catheter tracking technique with partial saturation pulse of 40° to visualize the gadolinium-filled balloon, CMR-conditional guidewire, and cardiac structures simultaneously to aid in completion of right (RHC) and left heart catheterization (LHC). Repeat iCMR and catheterization measurements were performed to compare reliability by the Pearson (PCC) and concordance correlation coefficients (CCC).

RESULTS

Thirty CHD (20 single ventricle and 10 bi-ventricular) subjects with a median age and weight of 8.3 years (2-33) and 27.7 kg (9.2-80), respectively,  successfully underwent iCMR RHC and LHC. No catheter related complications were encountered. Time taken for first pass RHC and LHC/aortic pull back was 5.1, and 2.9 min, respectively. Total success rate to obtain required data points to complete Fick principle calculations for all patients was 321/328 (98%). One patient with multiple shunts was an outlier and excluded from further analysis. The PCC for catheter-derived pulmonary blood flow (Qp) (0.89, p < 0.001) is slightly lower than iCMR-derived Qp (0.96, p < 0.001), whereas catheter-derived systemic blood flow (Qs) (0.62, p = < 0.001) was considerably lower than iCMR-derived Qs (0.94, p < 0.001). CCC agreement for Qp at baseline (C1-CCC = 0.65, 95% CI 0.41-0.81) and retested conditions (C2-CCC = 0.78, 95% CI 0.58-0.89) were better than for Qs at baseline (C1-CCC = 0.22, 95% CI - 0.15-0.53) and retested conditions (C2-CCC = 0.52, 95% CI 0.17-0.76).

CONCLUSION

This study further validates hemodynamic measurements obtained via iCMR. iCMR-derived flows have considerably higher test-retest reliability for Qs. iCMR evaluations allow for more reproducible hemodynamic assessments in the CHD population.