Three-dimensional image fusion guidance of percutaneous pulmonary valve implantation to reduce radiation exposure and contrast dose: A comparison with traditional two-dimensional and three-dimensional rotational angiographic guidance

Fusion imaging for guidance of pulmonary arteriovenous malformation embolisation with minimal radiation and contrast exposure

Hereditary haemorrhagic telangiectasia is an inherited disorder characterised by vascular dysplasia that leads to the development of arteriovenous malformations. Pulmonary arteriovenous malformations occur in approximately 30% of patients with haemorrhagic telangiectasia. Given the complex characteristics of haemorrhagic telangiectasia lesions, the application of three-dimensional fusion imaging holds significant promise for procedural guidance and decrease in contrast and radiation dosing. We reviewed all patients who underwent transcatheter approach for pulmonary arteriovenous malformation occlusion with fusion image guidance from June 2018 to September 2023 from a single centre. A total of nine cases with haemorrhagic telangiectasia and transcatheter occlusion of pulmonary arteriovenous malformations using fusion imaging were identified. Five (56%) were male, mean age at procedure was 15.7 years (10-28 years) and mean number of pulmonary arteriovenous malformations intervened was three per patient (1-7). Two of the cases were complex repeat embolisations. The mean fluoroscopy time was 40.6 min (10.7-68.8 min), with mean contrast dose of 28.8 mL (11-60 mL; mean of 0.51 mL/kg) and mean radiation dose of 66.3 mGy (25.6-140 mGy; mean of 40.5 mGy/m2). There were no complications reported during the procedures, with no additional interventions necessary. Fusion imaging in pulmonary arteriovenous malformations embolisation for patients with haemorrhagic telangiectasia is feasible and has the potential to reduce contrast and radiation doses. To our knowledge, we describe the lowest radiation and contrast doses per patient using fusion imaging technology reported in the literature to date.

Multimodality 3D image fusion with live fluoroscopy reduces radiation dose during catheterization of congenital heart defects

Introduction

Imaging fusion technology is promising as it is radiation and contrast sparing. Herein, we compare conventional biplane angiography to multimodality image fusion with live fluoroscopy using two-dimensional (2D)-three-dimensional (3D) registration (MMIF2D-3D) and assess MMIF2D-3D impact on radiation exposure and contrast volume during cardiac catheterization of patients with congenital heart disease (CHD).

Methods

We matched institutional MMIF2D-3D procedures and controls according to patient characteristics (body mass index, age, and gender) and the seven procedure-type subgroups. Then, we matched the number of tests and controls per subgroup using chronological ordering or propensity score matching. Subsequently, we combined the matched subgroups into larger subgroups of similar procedure type, keeping subgroups with at least 10 test and 10 control cases. Air kerma (AK) and dose area product (DAP) were normalized by body weight (BW), product of body weight and fluoroscopy time (BW × FT), or product of body weight and number of frames (BW × FR), and stratified by acquisition plane and irradiation event type (fluoroscopy or acquisition). Three senior interventionists evaluated the relevance of MMIF2D-3D (5-point Likert scale).

Results

The Overall group consisted of 54 MMIF2D-3D cases. The combined and matched subgroups were pulmonary artery stenting (StentPUL), aorta angioplasty (PlastyAO), pulmonary artery angioplasty (PlastyPUL), or a combination of the latter two (Plasty). The FT of the lateral plane reduced significantly by 69.6% for the Overall MMIF2D-3D population. AKBW and DAPBW decreased, respectively, by 43.9% and 39.3% (Overall group), 49.3% and 54.9% (PlastyAO), and 36.7% and 44.4% for the Plasty subgroup. All the aforementioned reductions were statistically significant except for DAPBW in the Overall and Plasty (sub)groups. The decrease of AKBW and DAPBW in the StentPUL and PlastyPUL subgroups was not statistically significant. The decrease in the median values of the weight-normalized contrast volume (CMCBW) in all five subgroups was not significant. Cardiologists considered MMIF2D-3D very useful with a median score of 4.

Conclusion

In our institution, MMIF2D-3D overall enabled significant AKBW reduction during the catheterization of CHD patients and was mainly driven by reduced FT in the lateral plane. We observed significant AKBW reduction in the Plasty and PlastyAO subgroups and DAPBW reduction in the PlastyAO subgroup. However, the decrease in CMCBW was not significant.

4D flow magnetic resonance imaging to assess right ventricular outflow tract in patients undergoing transcatheter pulmonary valve replacement

INTRODUCTION AND OBJECTIVES

Magnetic resonance imaging (MRI) including 4D flow is used before percutaneous pulmonary valve implantation (PPVI). As PPVI is limited by the size of the right ventricular outflow tract (RVOT), accurate sizing is needed to plan the intervention. The aim of this study was to compare different MRI modalities and invasive angiography to balloon sizing of RVOT.

METHODS

Single-center prospective study of patients who underwent PPVI for isolated pulmonary regurgitation assessed by 4D flow MRI, 3D steady-state free precession/gradient echo (3D SSFP/GRE) and contrast magnetic resonance angiography. Balloon sizing was considered as the reference.

RESULTS

A total of 23 adults were included (mean age, 38.4±12.5 years). Eighteen patients underwent successful primary PPVI. The average of the narrowest RVOT diameter was 25.4±4.3 mm by balloon sizing. Compared to balloon sizing, RVOT diameters were better correlated when estimated by systolic 4D flow MRI (r=0.89, P<.001) than by diastolic 4D flow MRI (r=0.71, P <.001), 3D contrast magnetic resonance angiography (r=0.73; P <.001) and 3D SSFP/GRE (r=0.50; P=.04) and was not significantly correlated when estimated by 2D in diastole and systole. The mean difference between systolic 4D flow MRI and balloon sizing was 0.2 mm (95%CI, -3.5 to 3.9 mm), whereas it was wider with other techniques.

CONCLUSIONS

Beyond the quantification of pulmonary valve regurgitation, 4D flow allows accurate estimation of RVOT diameters, especially in systole, which is fundamental before planning PPVI.

Optimizing 3D Rotational Angiography for Congenital Cardiac Catheterization

The aim of the study was to determine the variables associated with high-quality (HQ) versus low-quality (LQ) three-dimensional rotational angiography (3DRA) and create guides for optimization of approach to 3DRA in congenital cardiac catheterization (CCC). CCC has adopted 3DRA as a mainstay, but there has not been systematic analysis of approach to and factors associated with HQ 3DRA. This was a single-center, retrospective study of 3DRAs using Canon Infinix-I platform. Reconstructions were graded by 3 interventionalists. Quality was dichotomized into HQ and LQ. Univariable analyses and multivariable logistic regression models were performed. From 8/2016 to 12/2018, 208 3DRAs were performed in 195 CCCs; median age 7 years (2, 16), weight 23 kg (12, 57). The majority of 3DRAs were performed in patients with biventricular physiology (N = 137, 66%) and in pulsatile sites (N = 144, 69%). HQ 3DRA (N = 182, 88%) was associated with greater total injection volume [2.20 mL/kg (1.44, 3.29) vs. 1.62 mL/kg (1.10, 1.98), p = 0.005] and more dilute contrast solution [60% (50, 100) vs. 100% (60, 100), p = 0.007], but not with contrast volume administered (p = 0.2) on univariable analysis. On multivariable logistic regression, HQ 3DRA was significantly associated with patient weight [OR 0.97 (95% CI (0.94, 0.99), p = 0.018], total injection volume [OR 1.04 (95% CI 1.01, 1.07) p = 0.011], and percent contrast solution [OR 0.97 (95% CI 0.95, 1.00), p = 0.022]. These data resulted in creation of scatter plots and a novel 3DRA Nomogram for estimating the probability of HQ 3DRA. This is the first study to create evidence-based contrast dose guides and nomogram for 3DRA in CCC. HQ 3DRA was associated with lower weight, higher total injection volumes, and more dilute contrast solution.

Non-invasive imaging prior to percutaneous pulmonary valve implantation

The majority of patients with congenital heart disease who have undergone open heart surgery during childhood are possible candidates for additional transcatheter or surgical interventions. One fifth of these conditions usually involve the right ventricular outflow tract (RVOT). Percutaneous pulmonary valve replacement (PPVR) has been widely established as an alternative, less invasive option to surgical pulmonary valve replacement (SPVR). The variability of RVOT anatomy and size, the relative course of the coronary arteries and the anatomy of the pulmonary artery branches are factors that determine the success of the intervention as well as the complication rates. Careful and reliable pre-interventional imaging warrants the selection of suitable candidates and minimizes the risk of complications. 2D and 3D fluoroscopy have been extensively used during pre- and peri-interventional assessment. Established imaging techniques such as Cardiovascular Magnetic Resonance (CMR) and Computed Tomography (CT), as well as newer techniques, such as fusion imaging, have proved to be efficient and reliable tools during pre-procedural planning in patients assessed for PPVR.

Renaissance of Cardiac Imaging to Assist Percutaneous Interventions in Congenital Heart Diseases:The Role of Three-Dimensional Echocardiography and Multimodality Imaging

Percutaneous interventions have completely refashioned the management of children with congenital heart diseases (CHD) and the use of non-invasive imaging has become the gold standard to plan and guide these procedures in the modern era. We are now facing a dual challenge to improve the standard of care in low-risk patients, and to shift our strategies from the classic open chest surgery to imaging-guided percutaneous interventions in high-risk patients. Such rapid evolution of ultrasound technologies over the last 20 years have permitted the integration of transthoracic, transesophageal and intracardiac echocardiography into the interventional workflow to improve image guidance and reduce radiation burden from fluoroscopy and angiography. Specifically, miniaturization of transesophageal probe and advances in three-dimensional (3D) imaging techniques have enabled real-time 3D image guidance during complex interventional procedure, In addition, multimodality and fusion imaging techniques harness the strengths of different modalities to enhance understanding of anatomical and spatial relationship between different structures, improving communication and coordination between interventionalists and imaging specialists. In this review, we aim to provide an overview of 3D imaging modalities and multimodal fusion in procedural planning and live guidance of percutaneous interventions. At the present times, 3D imaging can no longer be considered a luxury but a routine clinical tool to improve procedural success and patient outcomes.

Contrast-free percutaneous pulmonary valve replacement: a safe approach for valve-in-valve procedures

Introduction

Percutaneous pulmonary valve replacement (PPVI) continues to gather pace in pediatric and adult congenital practice. This is fueled by an expanding repertoire of devices, techniques and equipment to suit the heterogenous anatomical landscape of patients with lesions of the right ventricular outflow tract (RVOT). Contrast-induced nephropathy is a real risk for teenagers and adults with congenital heart disease (CHD).

Aim

To present a series of patients who underwent PPVI without formal RVOT angiography and propose case selection criteria for patients who may safely benefit from this approach.

Material and methods

We retrospectively collected PPVI data from the preceding 2 years at our institution identifying patients who had been listed as suitable for consideration for contrast-free PPVI from our multidisciplinary team (MDT) meeting based on predefined criteria. Demographic, clinical, imaging and hemodynamic data were collected. Data were analyzed using SPSS.

Results

Twenty-one patients were identified. All patients had a technically successful implantation with improvements seen in invasive and echocardiographic hemodynamic measurements. 90% of patients had a bio-prosthetic valve (BPV) in situ prior to PPVI. One patient had a complication which may have been recognized earlier with post-intervention RVOT contrast injection.

Conclusions

Zero-contrast PPVI is technically feasible and the suitability criteria for those who might benefit are potentially straightforward. The advent of fusion and 3D imaging in cardiac catheterization laboratories is likely to expand our capacity to perform more procedures with less contrast. Patients with bio-prosthetic valves in the pulmonary position may benefit from contrast-free percutaneous pulmonary valve implantation.

Novel Minimal Radiation Approach for Percutaneous Pulmonary Valve Implantation

The aim of the study is to evaluate the impact of multimodality imaging technology during percutaneous pulmonary valve implantation (PPVI). Among percutaneous procedures, PPVI traditionally has one of the highest patient radiation exposures. Different protocol modifications have been implemented to address this problem (i.e., improvements in guidance systems, delivery systems, valve design, post-implantation evaluation). Although the effectiveness of individual modifications has been proven, the effect of an approach which combines these changes has not been reported. We performed a retrospective chart review of 76 patients who underwent PPVI between January 2018 and December 2019. Patients were classified in "Traditional protocol," using routine biplane angiography and/or 3D rotational angiography (3DRA); and "Multimodality protocol" that included the use of VesselNavigator for guidance, selective 3DRA for coronary evaluation, Long DrySeal Sheath for valve delivery, and Intracardiac Echocardiography for valve evaluation after implantation. Radiation metrics, procedural time, and clinical outcomes were compared between groups. When the traditional protocol group was compared with the multimodality protocol group, a significant reduction was described for total fluoroscopy time (31.6 min vs. 26.2 min), dose of contrast per kilogram (1.8 mL/Kg vs. 0.9 mL/Kg), DAP/kg (26.6 µGy·m²/kg vs. 19.9 µGy·m²/kg), and Air Kerma (194 mGy vs. 99.9 mGy). A reduction for procedure time was noted (140 min vs. 116.5 min), but this was not statistically significant. There was no difference in clinical outcomes or the presence of complications between groups. The combination of novel technology in PPVI caused a significant reduction in radiation metrics without increasing the complication rate in our population.

Innovations in Congenital Interventional Cardiology

This article aims to summarize some of the key advances in congenital interventional cardiology over the past few years, from novel imaging technologies, such as virtual reality, fusion imaging, and 3-dimensional printed models, to newly available devices and techniques to facilitate complex procedures including percutaneous pulmonary valve replacement and hybrid procedures. It is an exciting time for the field, with rapid development of techniques, devices, and imaging tools that allow a minimally invasive approach for many congenital cardiac defects with progressively less radiation and contrast doses.

Emerging 3D technologies and applications within congenital heart disease: teach, predict, plan and guide

3D visualization technologies have evolved to become a mainstay in the management of congenital heart disease (CHD) with a growing presence within multiple facets. Printed and virtual 3D models allow for a more comprehensive approach to educating trainees and care team members. Computational fluid dynamics can take 3D modeling to the next level, by predicting post-procedural outcomes and helping to determine surgical approach. 3D printing and extended reality are developing resources for pre-procedural planning and intra-procedural guidance with the potential to revolutionize decision-making and procedural success. Challenges still remain within existing technologies and their applications to the CHD field. Addressing these gaps, both by those within and outside of CHD, will transform education and patient care within our field.

Three-Dimensional Rotational Angiography during Catheterization of Congenital Heart Disease - A ten Years' experience at a single center

This paper aims to assess the usability and advantages of three-dimensional rotational angiography (3DRA) in patients with congenital heart disease (CHD) and its application in the cath lab. Up to now, its use in CHD is not widespread or standardized. We analyzed all patients with CHD who underwent a 3DRA at our facility between January 2010 and May 2019. The 3DRAs were evaluated for radiation exposure, contrast dye consumption, diagnostic utility and image quality. We performed 872 3DRAs. 3DRA was used in 67.1% of the cases for interventional procedures and in 32.9% for diagnostic purposes. Two different acquisition programs were applied. The median dose-area product (DAP) for all 872 rotations was 54.1 µGym² (21.7–147.5 µGym²) and 1.6 ml/kg (0.9–2.07 ml/kg) of contrast dye was used. Diagnostic utility of the generated 3D-model was rated superior to the native 3D angiography in 94% (819/872). 3DRA is an excellent and save diagnostic and interventional tool. However, 3DRA has not become a standard imaging procedure in pediatric cardiology up to now. Effort and advantage seems to be unbalanced, but new less invasive techniques may upgrade this method in future.

Percutaneous Pulmonary Valve Implantation

Percutaneous pulmonary valve implantation (PPVI) is recognized as a feasible and low risk alternative to surgery to treat dysfunctional right ventricular outflow tract (RVOT) in usually pluri-operated patients. Evolving technology allowed to develop different kind of prosthesis and to go from an initial treatment exclusively of stenotic conduit to an actual approach extended also to wide native RVOT. The Melody transcatheter pulmonary valve (TPV) and the Edwards Sapien valve are nowadays the most commonly implanted prostheses. However, other devices have been developed to treat large RVOT (i.e., the Venus p-valve, the Medtronic Harmony TPV, the Alterra Adaptive Prestent, and the Pulsta valve). Indications for PPVI are the same as for surgical interventions on pulmonary valve, with limits related to the maximum diameter of the available percutaneous prosthesis. Therefore, an accurate preoperative evaluation is of paramount importance to select patients who could benefit from this procedure. The overall periprocedural mortality incidence is around 1.4%, while freedom from RVOT reintervention ranges from 100% at 4 months to 70% at 70 months, according to the different published studies.

MRI Catheterization: Ready for Broad Adoption

In recent years, interventional cardiac magnetic resonance imaging (iCMR) has evolved from attractive theory to clinical routine at several centers. Real-time cardiac magnetic resonance imaging (CMR fluoroscopy) adds value by combining soft-tissue visualization, concurrent hemodynamic measurement, and freedom from radiation. Clinical iCMR applications are expanding because of advances in catheter devices and imaging. In the near future, iCMR promises novel procedures otherwise unsafe under standalone X-Ray guidance.

Percutaneous Pulmonary Valve Implantation

Percutaneous pulmonary valve implantation (PPVI) is recognized as a feasible and low risk alternative to surgery to treat dysfunctional right ventricular outflow tract (RVOT) in usually pluri-operated patients. Evolving technology allowed to develop different kind of prosthesis and to go from an initial treatment exclusively of stenotic conduit to an actual approach extended also to wide native RVOT. The Melody transcatheter pulmonary valve (TPV) and the Edwards Sapien valve are nowadays the most commonly implanted prostheses. However, other devices have been developed to treat large RVOT (i.e., the Venus p-valve, the Medtronic Harmony TPV, the Alterra Adaptive Prestent, and the Pulsta valve). Indications for PPVI are the same as for surgical interventions on pulmonary valve, with limits related to the maximum diameter of the available percutaneous prosthesis. Therefore, an accurate preoperative evaluation is of paramount importance to select patients who could benefit from this procedure. The overall periprocedural mortality incidence is around 1.4%, while freedom from RVOT reintervention ranges from 100% at 4 months to 70% at 70 months, according to the different published studies.

Preprocedural three-dimensional planning aids in transcatheter ductal stent placement: A single-center experience

OBJECTIVES

Describe the use of three-dimensional (3D) patent ductus arteriosus (PDA) modeling to better define ductal anatomy to improve preprocedural planning for ductal stent placement.

BACKGROUND

Ductal stenting is an alternative to surgical shunting in patients with ductal dependent pulmonary blood flow. Ductal anatomy is often complex with extreme tortuosity and risk of pulmonary artery isolation, thus increasing procedural risks.

METHODS

CT angiograms were segmented to produce 3D PDA models. Ductal morphology was characterized with attention to access approach, degree of pulmonary artery offset/risk of isolation and ductal tortuosity. 3D models were retrospectively compared with biplane angiography.

RESULTS

3D modeling was performed in 12 patients with adequate image quality for complete analysis in 11; median (interquartile range) age/weight 17 days (8-20 days) and 3.1 kg (2.4-3.9 kg). The PDA was reverse oriented in nine with average length of 17.2 ± 2.5 mm and high tortuosity (mean tortuosity index 52, range 3-108). From 3D modeling, two patients were excluded from ductal stenting-extreme ductal tortuosity and threatened pulmonary artery discontinuity, respectively. Ductal stenting was successful in the remaining nine with no major procedural complications. 3D modeling predicted a successful access approach based on the aortic orientation of the ductus in all patients (five carotid, two axillary, two femoral). When comparing 2D angiography with 3D models, angiography consistently underestimated ductal length (-3.2 mm ± 1.6 mm) and tortuosity (-14.8 ± 7.2).

CONCLUSIONS

3D modeling prior to ductal stent placement for ductal dependent pulmonary blood flow is useful in procedural planning, specifically for eligibility, access approach, and accurate ductal measurements. Further studies are needed to determine if 3D planning improves procedural outcomes.

Giving up knowledge is almost never a good idea: an interview with Dr Evan Zahn

The history of congenital interventional cardiology has seen numerous groundbreaking innovations typically related to the introduction of a new device or a novel treatment technique. Similarly, imaging of cardiac defects has changed dramatically over the past decades, although some of the advancements have seemed to omit the catheterisation laboratories. Rotational angiography, one of the imaging techniques for guidance of cardiac catheterisation currently referred to as "advanced", in fact was described already in 1960s.1 More recently its improved version, including three-dimensional reconstruction (3DRA), became a valuable intra-procedural imaging tool in interventional cardiology and neuroradiology.2 Dr Evan Zahn was one of the pioneers of 3DRA in the field of congenital cardiology, setting an example for many to follow. With his innovative publication and subsequent lecture at 2011 Pediatric and Adult Interventional Cardiac Symposium (PICS-AICS) on "The Emerging Use of 3-Dimensional Rotational Angiography in Congenital Heart Disease" he motivated many to explore benefits of this modality to strive for improved procedural outcomes and reduced patients' burden of cardiac catheterisation3. I was one of those to take Dr Zahn's thoughts and implement them into routine workflow.4-6 However, almost a decade after Dr Zahn shared his important work, despite tremendous efforts by teams from Utrecht, (Netherlands) and Columbus (Ohio, United States of America) to popularise 3D imaging in catheterisation laboratory during dedicated meetings, two-dimensional (2D) angiography does not seem to be threatened in many, otherwise-progressive, laboratories. During the recent 30th Japanese Pediatric Interventional Cardiology (JPIC) meeting I had the opportunity to ask Dr Zahn why giving up knowledge is almost never a good idea, what is technology's natural order of things, and why the technology has to be more than just exciting, pretty, and new.

Percutaneous Pulmonary Valve Implantation: Current Status and Future Perspectives

Patients with congenital heart disease (CHD) with right ventricle outflow tract (RVOT) dysfunction need sequential pulmonary valve replacements throughout their life in the majority of cases. Since their introduction in 2000, the number of percutaneous pulmonary valve implantations (PPVI) has grown and reached over 10,000 procedures worldwide. Overall, PPVI has been proven safe and effective, but some anatomical variations can limit procedural success. This review discusses the current status and future perspectives of the procedure.

Pros, cons and future perspectives - three questions on three dimensional guidance for cardiac catheterization in congenital heart disease

Step changes in angiographic imaging are not commonplace. Since the move from analogue to digital and flat detector plates, two-dimensional imaging technology has certainly evolved but not jumped forward. Of all the routine imaging techniques used in cardiology, angiography has been the last modality to embrace the third dimension. Although the development of rotational angiography was initially for the benefit of neuroimaging and fusion of cross sectional datasets was aimed at the treatment of descending aortic pathology, interventional physicians in congenital and structural cardiology have immersed themselves in this technology over the last 10 years. Like many disruptive technologies, its introduction has divided opinion. We aimed to explore the mindset of those in the field of interventional cardiology who are driving imaging forward. These structured interviews recorded during the 21^st Pediatric and Adult Interventional Cardiac Symposium illustrate the challenges and sticking points as well as giving an insight into the direction of travel for three-dimensional imaging and fusion techniques. Covering a wide range of career development, seniority and experience, the interviewees in this article are probably responsible for the majority of the published literature on invasive three-dimensional imaging in congenital heart disease.

Three-dimensional rotational angiography in congenital heart disease: Present status and evolving future

Three-dimensional rotational angiography (3D-RA) enables volumetric imaging through rotation of the C-arm of an angiographic system and real-time 3D reconstruction during cardiac catheterization procedures. In the field of congenital heart disease (CHD), 3D-RA has gained considerable traction, owing to its capability for enhanced visualization of spatial relationships in complex cardiac morphologies and real time image guidance in an intricate interventional environment. This review provides an overview of the current applications, strengths, and limitations of 3D-RA acquisition in the management of CHD and potential future directions. In addition, issues of dosimetry, radiation exposure, and optimization strategies will be reviewed. Further implementation of 3D-RA will be driven by patient benefits relative to existing 3D imaging capabilities and fusion techniques balanced against radiation exposure.

EDUCATIONAL SERIES IN CONGENITAL HEART DISEASE: Tetralogy of Fallot: diagnosis to long-term follow-up

Tetralogy of Fallot (TOF) is the most common cyanotic congenital heart defect, affecting 3 in 10,000 live births. Surgical correction in early childhood is associated with good outcomes, but lifelong follow-up is necessary to identify the long-term sequelae that may occur. This article will cover the diagnosis of TOF in childhood, the objectives of surveillance through adulthood and the value of multi-modality imaging in identifying and guiding timely surgical and percutaneous interventions.

Three-Dimensional Rotational Angiography in Pediatric Patients with Congenital Heart Disease: A Literature Review

Cardiac catheterization is a commonly used form of imaging and treatment in pediatric patients with congenital heart disease. Traditionally, two-dimensional conventional angiography was the method used, but since 2000 three-dimensional rotational angiography (3DRA) is increasingly used in the field of cardiology in both adult and pediatric patients. To investigate the use and applications of 3DRA in pediatric congenital cardiology, literature was systematically reviewed and 29 eligible articles were found. Those showed that 3DRA is already a greatly valued diagnostic and therapeutic technique in pediatric cardiology. However, the literature misses well-designed clinical, homogeneous, multicenter, prospective studies recording data in a standardized manner. These studies are necessary to ensure proper data analysis and to investigate the true advantages of 3DRA and how it exactly benefits the patients.

Magnetic resonance and computed tomography imaging fusion for live guidance of percutaneous pulmonary valve implantation

Introduction

Until recently, two-dimensional (2D) angiography was the mainstay of guidance for percutaneous pulmonary valve implantation (PPVI). Recent advances in fusion software have enabled direct fusion of pre-intervention imaging, magnetic resonance imaging (MRI) or computed tomography (CT) scans, to create a reliable three-dimensional (3D) roadmap for procedural guidance.

Aim

To report initial two-center experience with direct 2D–3D image fusion for live guidance of PPVI with MRI- and CT-derived 3D roadmaps.

Material and methods

We performed a prospective study on PPVIs guided with the new fusion imaging platform introduced in the last quarter of 2015.

Results

3D guidance with an MRI- (n = 14) or CT- (n = 8) derived roadmap was utilized during 22 catheterizations for right ventricular outflow tract balloon sizing (n = 7) or PPVI (n = 15). Successful 2D–3D registration was performed in all but 1 patient. Six (27%) patients required intra-procedural readjustment of the 3D roadmap due to distortion of the anatomy after introduction of a stiff wire. Twenty-one (95%) interventions were successful in the application of 3D imaging. Patients in the CT group received less contrast volume and had a shorter procedural time, though the differences were not statistically significant. Those in the MRI group had significantly lower weight adjusted radiation exposure.

Conclusions

With intuitive segmentation and direct 2D–3D fusion of MRI or CT datasets, VesselNavigator facilitates PPVI. Our initial data show that utilization of CT-derived roadmaps may lead to less contrast exposure and shorter procedural time, whereas application of MRI datasets may lead to lower radiation exposure.

Adult congenital heart disease: magnitude of the problem

PURPOSE OF REVIEW

To define the magnitude of problems faced by patients with adult congenital heart disease (ACHD) and to identify unmet needs for this population.

RECENT FINDINGS

The ACHD population is estimated to include more than 1 million people in the United States and continues to grow at a steady rate. Owing to the decline in early mortality in this group, modern medicine is now faced by the long-term complications associated with congenital heart disease such as chronic heart failure, increased endocarditis risk, elevated burden of arrhythmias, pulmonary hypertension, valvular dysfunction, and pregnancy.

SUMMARY

Increasing access to ACHD care, evolution of imaging techniques and transcatheter technology and continued efforts at quality improvement will be key to successfully facing the challenges that are a product of the astounding success of pediatric cardiac surgery.

Recent advances in cardiac catheterization for congenital heart disease

The field of pediatric and adult congenital cardiac catheterization has evolved rapidly in recent years. This review will focus on some of the newer endovascular technological and management strategies now being applied in the pediatric interventional laboratory. Emerging imaging techniques such as three-dimensional (3D) rotational angiography, multi-modal image fusion, 3D printing, and holographic imaging have the potential to enhance our understanding of complex congenital heart lesions for diagnostic or interventional purposes. While fluoroscopy and standard angiography remain procedural cornerstones, improved equipment design has allowed for effective radiation exposure reduction strategies. Innovations in device design and implantation techniques have enabled the application of percutaneous therapies in a wider range of patients, especially those with prohibitive surgical risk. For example, there is growing experience in transcatheter duct occlusion in symptomatic low-weight or premature infants and stent implantation into the right ventricular outflow tract or arterial duct in cyanotic neonates with duct-dependent pulmonary circulations. The application of percutaneous pulmonary valve implantation has been extended to a broader patient population with dysfunctional ‘native’ right ventricular outflow tracts and has spurred the development of novel techniques and devices to solve associated anatomic challenges. Finally, hybrid strategies, combining cardiosurgical and interventional approaches, have enhanced our capabilities to provide care for those with the most complex of lesions while optimizing efficacy and safety.

Novel Three-Dimensional Image Fusion Software to Facilitate Guidance of Complex Cardiac Catheterization : 3D image fusion for interventions in CHD

We report initial experience with novel three-dimensional (3D) image fusion software for guidance of transcatheter interventions in congenital heart disease. Developments in fusion imaging have facilitated the integration of 3D roadmaps from computed tomography or magnetic resonance imaging datasets. The latest software allows live fusion of two-dimensional (2D) fluoroscopy with pre-registered 3D roadmaps. We reviewed all cardiac catheterizations guided with this software (Philips VesselNavigator). Pre-catheterization imaging and catheterization data were collected focusing on fusion of 3D roadmap, intervention guidance, contrast and radiation exposure. From 09/2015 until 06/2016, VesselNavigator was applied in 34 patients for guidance (n = 28) or planning (n = 6) of cardiac catheterization. In all 28 patients successful 2D-3D registration was performed. Bony structures combined with the cardiovascular silhouette were used for fusion in 26 patients (93%), calcifications in 9 (32%), previously implanted devices in 8 (29%) and low-volume contrast injection in 7 patients (25%). Accurate initial 3D roadmap alignment was achieved in 25 patients (89%). Six patients (22%) required realignment during the procedure due to distortion of the anatomy after introduction of stiff equipment. Overall, VesselNavigator was applied successfully in 27 patients (96%) without any complications related to 3D image overlay. VesselNavigator was useful in guidance of nearly all of cardiac catheterizations. The combination of anatomical markers and low-volume contrast injections allowed reliable 2D-3D registration in the vast majority of patients.

Real-time three dimensional CT and MRI to guide interventions for congenital heart disease and acquired pulmonary vein stenosis

To validate the feasibility and spatial accuracy of pre-procedural 3D images to 3D rotational fluoroscopy registration to guide interventional procedures in patients with congenital heart disease and acquired pulmonary vein stenosis. Cardiac interventions in patients with congenital and structural heart disease require complex catheter manipulation. Current technology allows registration of the anatomy obtained from 3D CT and/or MRI to be overlaid onto fluoroscopy. Thirty patients scheduled for interventional procedures from 12/2012 to 8/2015 were prospectively recruited. A C-arm CT using a biplane C-arm system (Artis zee, VC14H, Siemens Healthcare) was acquired to enable 3D3D registration with pre-procedural images. Following successful image fusion, the anatomic landmarks marked in pre-procedural images were overlaid on live fluoroscopy. The accuracy of image registration was determined by measuring the distance between overlay markers and a reference point in the image. The clinical utility of the registration was evaluated as either "High", "Medium" or "None". Seventeen patients with congenital heart disease and 13 with acquired pulmonary vein stenosis were enrolled. Accuracy and benefit of registration were not evaluated in two patients due to suboptimal images. The distance between the marker and the actual anatomical location was 0-2 mm in 18 (64%), 2-4 mm in 3 (11%) and >4 mm in 7 (25%) patients. 3D3D registration was highly beneficial in 18 (64%), intermediate in 3 (11%), and not beneficial in 7 (25%) patients. 3D3D registration can facilitate complex congenital and structural interventions. It may reduce procedure time, radiation and contrast dose.