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.

Contemporary Review of Transcatheter Mitral Valve Interventions for Mitral Regurgitation

Mitral regurgitation (MR) is the most common form of valvular heart disease in the United States, and there are established guidelines for indications for requiring mitral valve surgeries. However, there is an unmet clinical need for a subset of high-risk MR patients, especially those with advanced age, heart failure and/or secondary MR. Following the successes of transcatheter aortic valve replacements, significant advances have occurred over the last decade in transcatheter mitral valve interventions in order to manage these patients in both clinical practice and trials. The three main types of these interventions include a transcatheter edge-to-edge repair, percutaneous mitral annuloplasty (both direct and indirect) and transcatheter mitral valve replacement (including when applied to a prior prosthetic valve, annuloplasty ring and mitral annuloplasty ring). This review aims to discuss the contemporary techniques, evidence, indications, multimodality imaging evaluations and outcomes of the various transcatheter mitral valve interventions.

Mitral Paravalvular Leak: Clinical Implications, Diagnosis and Management

Paravalvular leak incidence after mitral surgical replacement ranges from 7% to 17%. Between 1% and 5% of these are clinically significant. Large PVLs can cause important clinical manifestations such as heart failure or haemolysis. Current guidelines consider that surgical reparation is the gold-standard therapy in symptomatic patients with paravalvular leak. However, these recommendations are based in non-randomized observational registries. On the other hand, transcatheter paravalvular leak closure has shown excellent results with a low rate of complications, and nowadays it is considered the first option in selected patients in some experienced centres. In this review, we summarize the clinical manifestations, diagnosis, procedural details, and results of transcatheter mitral PVL closure.

EVALUATION OF RADIATION DOSES USING CONE BEAM COMPUTED TOMOGRAPHY IN ENDOVASCULAR AORTIC REPAIR AND SCOLIOSIS PROCEDURES

The aim of this project was to evaluate the radiation dose to patients for cone beam computed tomography (CBCT) in endovascular aortic repair (EVAR) and scoliosis procedures and to compare radiation doses between CBCT and computed tomography (CT). An anthropomorphic phantom and Siemens and General Electric X-ray equipment were used. Default protocol settings were used for comparison of protocols and modalities. The ratio between the highest and lowest CBCT effective dose, for each equipment, had a maximum of 13 (Artis Pheno) for EVAR and 1.8 (Artis Zeego) for scoliosis. It is difficult to predict which modality gives the highest effective dose, e.g. for the CT protocol 'Aorta before EVAR' the ratio between effective doses varied from 0.12 to 1.8, between CBCT and CT. For CBCT EVAR, the effective dose and dose area product decreased using collimation or zoom.

Cardiac Computed Tomography for Structural Heart Disease Assessment and Therapeutic Planning: Focus on Prosthetic Valve Dysfunction

Of the 100,000-plus valve surgeries performed each year in the United States, up to 6% of those develop complications from prosthetic valve dysfunction. Prosthetic valve dysfunction (PVD) can be life threatening and often challenging to diagnose. In this review, we discuss the prevalence and incidence of PVD, explore its different etiologies, and assess the role of multimodality imaging with an emphasis on cardiac multidetector computed tomography (MDCT) for evaluating patients with PVD. We also investigate the utility of MDCT in preprocedural planning for transcatheter devices and redo surgical planning and discuss management strategies for patients with PVD.

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.

Complex Structural Interventions: The Role of Computed Tomography, Fluoroscopy, and Fusion Imaging

Noninvasive cardiac imaging has played a critical part in the evaluation, monitoring, and follow-up of structural heart disease. This review will highlight the role of cardiac computed tomography, fluoroscopy, and fusion imaging in guiding transcatheter aortic valve replacement and other percutaneous strategies used to diagnose and treat complex structural heart complications.

Use of 3-D digital subtraction rotational angiography during cardiac catheterization of infants and adults with congenital heart diseases

OBJECTIVE

To compare image quality, radiation and contrast doses required to obtain 3D-Digital subtraction rotational angiography (3D-DSRA) with 3D-Digital rotational angiography (3D-DRA) in infants (children ≤ 2 years of age) and adults with congenital heart diseases (ACHD).

BACKGROUND

3D-DRA can be performed with radiation doses comparable to bi-plane cine-angiography. However, 3D-DRA in infants requires a large contrast volume. The resolution of 3D-DRA performed in ACHD patients is limited by their soft tissue density. We hypothesized that the use of 3D-DSRA could help alleviate these concerns.

METHODS

Radiation (DAP) and contrast doses required to obtain 3D-DSRA was compared with 3D-DRA in 15 age-, size-, and intervention-matched infants and 15 ACHD patients. The diagnostic quality and utility of these two modalities were scored by 4 qualified independent observers.

RESULTS

Both in infants and adults, the median contrast volume for 3D-DSRA was lower than 3D-DRA (0.98 vs. 1.81 mL/kg; P < 0.001 and 0.92 vs. 1.4 mL/kg; P < 0.001, respectively) with an increased DAP (median: 188 vs. 128 cGy cm² ; P = 0.068 and 659 vs. 427 cGy cm² ; P = 0.045, respectively). The diagnostic quality and utility scores for rotational-angiography, and 3D-reconstruction were superior for 3D-DSRA (score = 94 vs. 80%, P = 0.03 and 90 vs.79%, P = 0.01, respectively) and equivalent for multi-planar-reformation and 3D-roadmapping in ACHD patients compared with 3D-DRA. All scores for both modalities were equivalent for infants.

CONCLUSIONS

3D-DSRA can be acquired using lower contrast volume with a mildly higher radiation dose than 3D-DRA in infants and ACHD patients. The diagnostic quality and utility scores for 3D-DSRA were higher in ACHD patients and equivalent for infants compared with 3D-DRA.

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.

Real-Time 3D CT Image Guidance for Transjugular Intrahepatic Portosystemic Shunt Creation Using Preoperative CT: A Prospective Feasibility Study of 20 Patients

OBJECTIVE

The purpose of this study is to prospectively evaluate the feasibility and efficacy of real-time 3D CT image guidance during transjugular intrahepatic portosystemic shunt (TIPS) creation.

SUBJECTS AND METHODS

Between October 2013 and December 2013, a total of 20 patients were prospectively enrolled in the present study. Previously acquired portal venous phase CT datasets and intraoperative CT datasets were registered on a dedicated workstation. We accomplished semiautomatic registration for the datasets of 11 of 20 patients (55%), and we performed manual registration for the datasets of the remaining nine patients. The selected volume of interest of the CT image showing the portal vein vasculature was overlaid onto the fluoroscopic display to provide real-time 3D CT image guidance during the procedure.

RESULTS

For all 20 patients, TIPS procedures were successfully performed by the same operator. The mean (± SD) number of needle passes required for portal vein entry was 1.8 ± 1.1 passes (range, 1-5 passes). The mean duration of radiographic fluoroscopy was 3.5 ± 1.1 minutes for portal vein entry and 11.4 ± 2.1 minutes for the whole procedure. The mean radiation dose used for the whole TIPS procedure was 295.5 ± 66.6 Gy · cm². No major technical complications were observed.

CONCLUSION

Real-time 3D guidance with the use of preoperative CT is feasible, safe, and effective for assisting in the creation of TIPS. This approach may result in a shorter procedural time and less radiation exposure. However, future studies are required to compare this method with other mapping techniques.

Three-Dimensional Rotational Angiography in the Pediatric Cath Lab: Optimizing Aortic Interventions

The aim of this study was to evaluate usability and accuracy of three-dimensional rotational angiography (3DRA) during interventions of the aorta in congenital heart disease (CHD). 3DRA is an accurate, encompassing and fast imaging technique in the cath lab. However, there is only few published data about its use during interventions in CHD. Between January 2010 and January 2014, 3DRA was performed in 77 patients with aortic issues: in 65 % cases, an intervention was performed, of which 72 % had aortic isthmus stenosis. Data were obtained retrospectively. The accuracy of 3DRA was evaluated on the basis of comparative measurements (n = 60) of the aortic diameter between 3DRA and conventional biplane angiography. Measurements presented a high accuracy with an average deviation of 3.89 % [±3 %] and a significant correlation of r = 0.99 after Pearson (p < 0.0001). Clinical benefit was assessed using a five-point Likert scale and could be shown in 98 %. Comparison with a control group showed a reduced fluoroscopy time from 10.2 to 8.30 min (median, p < 0.01) and decreased radiation dose of 0.18 compared to 0.56 Gy cm(2)/kg (median, p < 0.02). The use of 3DRA in patients with aortic anomalies has advantages in comparison with conventional angiography. It improves diagnostic accuracy, and 3D guidance enables a faster and simplified intervention with enhanced patients' safety and the potential to reduce radiation dose.

Multimodality 3-dimensional image integration for congenital cardiac catheterization

Cardiac catheterization procedures for patients with congenital and structural heart disease are becoming more complex. New imaging strategies involving integration of 3-dimensional images from rotational angiography, magnetic resonance imaging (MRI), computerized tomography (CT), and transesophageal echocardiography (TEE) are employed to facilitate these procedures. We discuss the current use of these new 3D imaging technologies and their advantages and challenges when used to guide complex diagnostic and interventional catheterization procedures in patients with congenital heart disease.

Hybrid Imaging During Transcatheter Structural Heart Interventions

Fusion of different imaging modalities has gained increasing popularity over the last decade. However, most fusions are done between static rather than dynamic images. In order to adequately visualize the complex three-dimensional structures of the beating heart, high-temporal and spatial image resolutions are mandatory. Currently, only the combination of transesophageal echocardiography with fluoroscopy allows real-time image fusion of high quality during structural heart disease (SHD) interventions. The use of markers as well as real-time image overlay greatly facilitates communication between SHD team members and potentially increases procedural success while reducing radiation dose and use of contrast. However, to date there is only limited evidence that fusion imaging improves safety and outcomes of SHD interventions. This review highlights the benefits of fusion imaging during SHD interventions such as transseptal puncture and closure of atrial septal defects and left atrial appendage as well as interventions on the mitral and aortic valve.

The Role of Preoperative and Intraoperative Imaging in Guiding Transcatheter Aortic Valve Replacement

Optimal intraprocedural imaging is central to transcatheter aortic valve replacement (TAVR). Familiarity with commonly used modalities is necessary. Real-time, intraprocedural imaging is provided by fluoroscopy and echocardiography to ensure proper valve position and deployment, and to assess for postdeployment complications. By providing anatomic information to real-time fluoroscopy, fusion imaging has the potential to positively affect TAVR. As newer generation valves are introduced and as TAVR is potentially offered to lower risk patient populations, it will be important to ensure that improvements in intraprocedural imaging lead to better outcomes.

Multimodality image guidance with Dyna-CT for transcatheter treatment of paravalvular leak of a stentless valve

The transcatheter treatment of paravalvular leaks (PVL) are technically challenging procedures; they pose increasing difficulty in cases where there is a stentless valve, without the usual fluoroscopic landmarks. Hence, there is limited experience in treating this defect percutaneously. We present a case of a patient with an aortic PVL of a stentless valve and how the integrated use of multi-imaging modalities (transesophageal echocardiography, computed tomography and rotational angiography) allowed the demarcation of landmarks onto live fluoroscopy and guided the transcatheter occlusion of the PVL.

CT-angiography-based evaluation of the aortic annulus for prosthesis sizing in transcatheter aortic valve implantation (TAVI)-predictive value and optimal thresholds for major anatomic parameters

BACKGROUND/OBJECTIVES

To evaluate the predictive value of CT-derived measurements of the aortic annulus for prosthesis sizing in transcatheter aortic valve implantation (TAVI) and to calculate optimal cutoff values for the selection of various prosthesis sizes.

METHODS

The local IRB waived approval for this single-center retrospective analysis. Of 441 consecutive TAVI-patients, 90 were excluded (death within 30 days: 13; more than mild aortic regurgitation: 10; other reasons: 67). In the remaining 351 patients, the CoreValve (Medtronic) and the Edwards Sapien XT valve (Edwards Lifesciences) were implanted in 235 and 116 patients. Optimal prosthesis size was determined during TAVI by inflation of a balloon catheter at the aortic annulus. All patients had undergone CT-angiography of the heart or body trunk prior to TAVI. Using these datasets, the diameter of the long and short axis as well as the circumference and the area of the aortic annulus were measured. Multi-Class Receiver-Operator-Curve analyses were used to determine the predictive value of all variables and to define optimal cutoff-values.

RESULTS

Differences between patients who underwent implantation of the small, medium or large prosthesis were significant for all except the large vs. medium CoreValve (all p's<0.05). Furthermore, mean diameter, annulus area and circumference had equally high predictive value for prosthesis size for both manufacturers (multi-class AUC's: 0.80, 0.88, 0.91, 0.88, 0.88, 0.89). Using the calculated optimal cutoff-values, prosthesis size is predicted correctly in 85% of cases.

CONCLUSION

CT-based aortic root measurements permit excellent prediction of the prosthesis size considered optimal during TAVI.

A pre-operative CT and non-contrast-enhanced C-arm CT registration framework for trans-catheter aortic valve implantation

Contrast-enhanced C-arm CT is routinely used for intra-operative guidance during the trans-catheter aortic valve implantation (TAVI); however, the requirement for contrast agent injection is not preferable, especially for patients with renal insufficiencies. To address this problem, we present a novel framework for fully automatic registration of pre-operative CT and non-contrast-enhanced C-arm CT. The proposed framework provides an improved workflow and minimizes the usage of contrast agent in the TAVI procedure. Our framework consists of three steps: coarse rigid-body alignment, anatomical knowledge-based prior deformation field generation, and fine deformable registration. We validated the proposed framework on 20 real patient data sets. Based on the 20 data sets, the mesh-to-mesh errors at the aortic root from different methods are measured. Our proposed method significantly outperforms the other state-of-the-art methods. Specifically, we achieve the registration accuracy at 1.76±0.43 mm which is clinically plausible. Quantitative evaluation on real non-contrast enhanced C-arm CT data sets confirms the applicability in the clinical usage. The proposed heart registration method is generic and hence can be easily applied to other cardiac applications.

Integration of MDCT and fluoroscopy using C-arm computed tomography to guide structural cardiac interventions in the cardiac catheterization laboratory

OBJECTIVES

Our study was aimed at evaluation of three-dimensional (3D)-CT overlay onto the catheterization laboratory fluoroscopy to guide structural cardiac interventions.

BACKGROUND

Current imaging for structural cardiac interventions (fluoroscopy, echocardiography) may not provide adequate guidance. The ability to integrate intracardiac 3D-CT imaging data in the cardiac catheterization laboratory may be beneficial, but has not yet been systematically studied.

METHODS

Thirty-two patients undergoing various catheterization laboratory procedures (transcatheter aortic valve replacement, paravalvular leak (PVL) closure, pulmonary vein (PV) stenting, etc.) were prospectively enrolled. The goal was to evaluate the feasibility and benefit of overlaying pre-procedural CT data onto the real-time procedural fluoroscopic image using the Syngo DynaCT Cardiac C-arm CT system (Siemens Healthcare, Forcheim, Germany).

RESULTS

The overlay was considered most helpful for patients undergoing PVL closure and PV stenting. The additional radiation exposure of the C-arm CT was a fraction of the total procedural dose (3.5% of total skin dose and 9.1% of total DAP).

CONCLUSIONS

Overlay of 3D-CT data onto the real-time procedural fluoroscopy in the cardiac catheterization laboratory is feasible to aide procedural guidance. The overlay was considered most helpful for patients undergoing PVL closure and PV stenting. The additional radiation dose is a small fraction of the total dose. © 2014 Wiley Periodicals, Inc.

CT angiography-fluoroscopy fusion imaging for percutaneous transapical access

OBJECTIVES

The aim of this proof-of-principle study is to validate the accuracy of fusion imaging for percutaneous transapical access (TA).

BACKGROUND

Structural heart disease interventions, including TA, are commonly obtained under fluoroscopic guidance, which lacks important spatial information. Computed tomographic angiography (CTA)-fluoroscopy fusion imaging can provide the 3-dimensional information necessary for improved accuracy in planning and guidance of these interventions.

METHODS

Twenty consecutive patients scheduled for percutaneous left ventricular puncture and device closure using CTA-fluoroscopy fusion guidance were prospectively recruited. The HeartNavigator software (Philips Healthcare, Best, the Netherlands) was used to landmark the left ventricular epicardium for TA (planned puncture site [PPS]). The PPS landmark was compared with the position of the TA closure device on post-procedure CTA (actual puncture site). The distance between the PPS and actual puncture site was calculated from 2 fixed reference points (left main ostium and mitral prosthesis center) in 3 planes (x, y, and z). The distance from the left anterior descending artery at the same z-plane was also assessed. TA-related complications associated with fusion imaging were recorded.

RESULTS

The median (interquartile range [IQR]) TA distance difference between the PPS and actual puncture site from the referenced left main ostium and mitral prosthesis center was 5.00 mm (IQR: 1.98 to 12.64 mm) and 3.27 mm (IQR: 1.88 to 11.24 mm) in the x-plane, 4.48 mm (IQR: 1.98 to 13.08 mm) and 4.00 mm (IQR: 1.62 to 11.86 mm) in the y-plane, and 5.57 mm (IQR: 3.89 to 13.62 mm) and 4.96 mm (IQR: 1.92 to 11.76 mm) in the z-plane. The mean TA distance to the left anterior descending artery was 15.5 ± 7.8 mm and 22.7 ± 13.7 mm in the x- and y-planes. No TA-related complications were identified, including evidence of coronary artery laceration.

CONCLUSIONS

With the use of CTA-fluoroscopy fusion imaging to guide TA, the actual puncture site can be approximated near the PPS. Moreover, fusion imaging can help maintain an adequate access distance from the left anterior descending artery, thereby, potentially reducing TA-related complications.

Guidance of treatment of perivalvular prosthetic leaks

Percutaneous closure of paravalvular leaks has grown into becoming a widely considered option for treatment of hemodynamically significant regurgitation in patients with valve prosthesis. Guidance provided by the use of cardiovascular imaging techniques before and during the intervention has proved its relevance to improve accuracy and, with it, the outcome of the procedure. It has also been essential in the successful evolution of the technique and the development of devices specifically designed for it. The present work reviews the role of imaging before, during and after treatment of perivalvular prosthetic leaks and the most recent and significant advances in it.

Can we talk? Reflections on effective communication between imager and interventionalist in congenital heart disease

The rapid proliferation of catheter-mediated treatments for congenital heart defects has brought with it a critical need for cooperation and communication among the numerous physicians supporting these new and complex procedures. New interdependencies between physicians in specialties including cardiac imaging, interventional cardiology, pediatric cardiology, anesthesia, cardiothoracic surgery, and radiology have become apparent, as centers have strived to develop the best systems to foster success. Best practices for congenital heart disease interventions mandate confident and timely input from an individual with excellent adjunctive imaging skills and a thorough understanding of the devices and procedures being used. The imager and interventionalist must share an understanding of what each offers for the procedure, use a common terminology and spatial orientation system, and convey concise and accurate information about what is needed, what is seen, and what cannot be seen. The goal of this article is to review how the cardiovascular imaging specialists and interventionalists can work together effectively to plan and execute catheter interventions for congenital heart disease.

Review of surgical prosthetic paravalvular leaks: diagnosis and catheter-based closure

Paravalvular leak (PVL) is an uncommon yet serious complication associated with surgical prosthetic valve implantation. Paravalvular leak can have significant clinical consequence such as congestive heart failure, haemolytic anaemia, and infective endocarditis. Recently, transcatheter therapy has been applied to the treatment of this disorder with reasonable procedural and clinical success. This review discusses the current state of PVLs, the utilization of multi-modality imaging in their diagnosis and treatment, and the available therapeutic options. Further aim of this review is to examine transcatheter therapy of PVLs including the principles, outcomes, and procedural-related complications.

The value of flat-detector computed tomography during catheterisation of congenital heart disease

OBJECTIVES

To analyse the diagnostic utility of flat-detector computed tomography imaging (FD-CT) in patients with congenital heart disease, including the value of image fusion to overlay three-dimensional (3D) reconstructions on fluoroscopic images during catheter-based interventions.

METHODS

We retrospectively analysed 62 consecutive paediatric patients in whom FD-CT was used during catheterisation of congenital heart disease. Expert operators rated the clinical value of FD-CT over conventional fluoroscopic imaging. Added radiation exposure and contrast medium volume were evaluated.

RESULTS

During a 12-month period, FD-CT was performed in 62 out of 303 cardiac catheterisations. Median patient age was 3.5 years. In 32/62 cases, FD-CT was used for diagnostic purposes, in 30/62 cases it was used in the context of interventions. Diagnostic utility was never rated as "misleading". It was classified as "not useful" in six cases (9.7%), "useful" in 18 cases (29.0%), "very useful" in 37 cases (59.7%) and "essential" in one case (1.6%). The median added dose-area product was 111.0 μGym(2), the required additional quantity of contrast medium was 1.6 ml/kg.

CONCLUSION

FD-CT provides useful diagnostic information in most of the patients investigated for congenital heart disease. The added radiation exposure and contrast medium volume are reasonable.