Contemporary multimodality non-invasive cardiac imaging protocols for tetralogy of Fallot.

Tetralogy of Fallot is the most prevalent cyanotic congenital heart disease, requiring lifelong multimodality non-invasive cardiac imaging, such as echocardiography, cardiothoracic computed tomography, and cardiac magnetic resonance imaging. As imaging techniques continuously evolve and are gradually integrated into clinical practice, there is a critical need to update multimodality imaging protocols. Over the last two decades, cardiothoracic computed tomography imaging techniques have advanced remarkably, significantly enhancing its role in evaluating patients with tetralogy of Fallot. In this review, we describe contemporary multimodality non-invasive cardiac imaging protocols for tetralogy of Fallot, emphasizing the expanding role of cardiothoracic computed tomography. Additionally, we present standardized reporting forms designed to facilitate the clinical adoption of these protocols.

Graph theory applications in congenital heart disease.

Graph theory can be used to address problems with complex network structures. Congenital heart diseases (CHDs) involve complex abnormal connections between chambers, vessels, and organs. We proposed a new method to represent CHDs based on graph theory, wherein vertices were defined as the spaces through which blood flows and edges were defined by the blood flow between the spaces and direction of the blood flow. The CHDs of tetralogy of Fallot (TOF) and transposition of the great arteries (TGA) were selected as examples for constructing directed graphs and binary adjacency matrices. Patients with totally repaired TOF, surgically corrected d-TGA, and Fontan circulation undergoing four-dimensional (4D) flow magnetic resonance imaging (MRI) were included as examples for constructing the weighted adjacency matrices. The directed graphs and binary adjacency matrices of the normal heart, extreme TOF undergoing a right modified Blalock-Taussig shunt, and d-TGA with a ventricular septal defect were constructed. The weighted adjacency matrix of totally repaired TOF was constructed using the peak velocities obtained from 4D flow MRI. The developed method is promising for representing CHDs and may be helpful in developing artificial intelligence and conducting future research on CHD.

Self-Expanding Pulmonary Valves in 53 Patients With Native Repaired Right Ventricular Outflow Tracts.

BACKGROUND: Self-expanding pulmonary valve grafts have been designed for percutaneous pulmonary valve implantation (PPVI) in patients with native repaired right ventricular (RV) outflow tracts (RVOTs). However, their efficacy, in terms of RV function and graft remodelling remain unclear. METHODS: Patients with native RVOTs who received Venus P-valve (N = 15) or Pulsta valve (N = 38) implants between 2017 and 2022 were enrolled. We collected data on patient characteristics and cardiac catheterization parameters as well as imaging and laboratory data before, immediately after, and 6 to 12 months after PPVI and identified risk factors for RV dysfunction. RESULTS: Valve implantation was successful in 98.1% of patients. The median duration of follow-up was 27.5 months. In the first 6 months after PPVI, all patients exhibited resolution of paradoxical septal motion and a significant reduction (P < 0.05) in RV volume, N-terminal pro-B-type natriuretic peptide levels, and valve eccentricity indices (-3.9%). Normalization of the RV ejection fraction (≥ 50%) was detected in only 9 patients (17.3%) and was independently associated with the RV end-diastolic volume index before PPVI (P = 0.03). Nine patients had residual or recurrent pulmonary regurgitation or paravalvular leak (graded as ≥ mild), which was associated with a larger eccentricity index (> 8%) and subsided by 12 months postimplantation. CONCLUSIONS: We identified the risk factors likely to be associated with RV dysfunction and pulmonary regurgitation following PPVI in patients with native repaired RVOTs. RV volume-based patient selection is recommended for PPVI of a self-expanding pulmonary valve, along with monitoring of graft geometry.

The implications of airway anomalies on children with congenital heart disease and bronchiolitis.

BACKGROUND: Bronchiolitis is a common airway infection in young children. Hemodynamically significant congenital heart disease (CHD) predicts a more complicated course. However, the role of airway anomalies remains unknown. METHODS: We retrospectively reviewed the records of patients under 2 years old, diagnosed with CHD, and admitted between January 2011 and December 2013, before the palivizumab era. Records of bronchiolitis admissions were also extracted. Patients were grouped according to CHD condition and airway anomalies. RESULTS: A total of 230 patients with CHD were enrolled. A total of 180 (78%) and 71 (31%) patients had hemodynamically significant CHD and airway anomalies, respectively. A total of 52 (22.6%) patients were admitted for bronchiolitis 78 times. Among them, 33 (63.5%) had hemodynamically significant CHD, and 28 (53.8%) had airway anomalies. In patients with bronchiolitis admissions, the mean ventilator use, intensive care unit stay, and hospital stay were 1.08, 4.08, and 15.19 days, respectively. When compared, the mean hospital stay for bronchiolitis patients with airway anomalies was significantly longer than that of those without airway anomalies (19.8 vs. 9.9 days, p = 0.008). When further divided the patients by the presence hemodynamic significance, patients with hemodynamically significant CHD and airway anomaly had longer hospital stay than those who had neither. (21.7 vs. 8.3 days, p = 0.004) Airway anomaly was a significant risk factor for longer hospital stay in linear regression model (p = 0.007). CONCLUSIONS: Airway anomalies are common in children with CHD and are associated with longer hospital stays on bronchiolitis admission. An active survey for airway anomalies and adequate prophylaxis for bronchiolitis infection might be important in the care of children with CHD associated with airway anomalies.

Computed tomography jellyfish angiography in pediatric endovascular interventions.

Contrast pooling (CP) reconstruction is widely used in computed tomography (CT) studies of congenital heart diseases. However, endovascular devices are usually obscured in CP. To improve visualization of the vascular lumen, we developed jellyfish angiography (JFA), a semitransparent blood pool inversion technique. Ten CT studies of patent ductus arteriosus (PDA) or coarctation of the aorta (CoA) were selected retrospectively for reconstruction using both CP and JFA. Four of the studies were conducted before the endovascular intervention, and six were conducted after the intervention. Radiology residents and pediatric cardiologists completed questionnaires regarding the reconstruction models. For radiology residents, JFA was superior to CP in postintervention PDA diagnosis, device evaluation, and overall satisfaction. For pediatric cardiologists, JFA outperformed CP in both PDA and CoA postintervention cases. Our findings show that JFA overcomes the disadvantages of CP and can improve the visualization of intraluminal devices which is essential for endovascular treatment evaluation.

Dynamic cardiac computed tomography characteristics of double-chambered right ventricle.

To introduce image characteristics of double-chambered right ventricle on cardiac computed tomography and set a diagnostic criterion for the diagnosis. We retrospectively collected and measured the right ventricular constrictive ratio on computed tomography images in children who had simple ventricular septal defects in the past 10 years, because double-chambered right ventricle is often associated with ventricular septal defects. The right ventricular constrictive ratio was defined as the subinfundibular cross-sectional intraluminal area during end-systole divided by the area during end-diastole in the same patient. We compared the right ventricular constrictive ratio between subjects with concomitant double-chambered right ventricle and those without. 52 children were included, and 23 (44.2%) of them have concomitant double-chambered right ventricle. In most cases (n = 21; 91.3%), the hypertrophied muscular bundles occur just inferior to the level of the supraventricular crest in the right ventricle. Mean right ventricular constrictive ratio in patients with double-chambered right ventricle (15%) was significantly smaller than that without (29%). A cut-off value of a right ventricular constrictive ratio less than 20.1% was established to diagnose double-chambered right ventricle with an 89.7% sensitivity and 78. 3% specificity. Right ventricular constrictive ratio can be a valuable asset for the preoperative diagnosis of double-chambered right ventricle with cardiac computed tomography.

Radiologist burnout: Trends in medical imaging utilization under the national health insurance system with the universal code bundling strategy in an academic tertiary medical centre.

PURPOSE: The utilization of diagnostic medical imaging has been growing worldwide. However, no study has investigated the trend in image utilization and the corresponding workload of radiologists under the National Healthcare Insurance (NHI) system with a code-bundling-based reimbursement strategy. We will analyse the trend in diagnostic imaging utilization and the corresponding workload of the radiologists at a single tertiary medical centre using the NHI system. MATERIALS AND METHODS: This was a retrospective study recruiting the diagnostic medical images, including X-rays, CT, and MR performed between 2005 and 2020 at a single medical centre. We investigated the change over time in image utilization and workload for interpreting the images. The two-sided Mann-Kendall test was used for the monotonic trend analysis and Sen's slope estimate was calculated for the annual mean change with the 95% confidence interval (CI). A P value < 0.05 was considered significant. RESULTS: A total of 10,069,583 examinations were performed at our institute from 2005 to 2020, including 7,821,880 X-rays, 1,665,787 CT, and 581,916 MR examinations. The numbers of examinations of X-rays, CT, and MR increased with average annual changes of 13,411.3 (95% CI = 11,875.0-14,773.8), 9,496.7 (95% CI = 8,845.3-9,828.7), and 2,417.1 (95% CI = 2,209.8-2,668.9) respectively, all P < 0.001. The proportion of cases including multiple examinations increased, growing from 21.5% (6,627 in 30,878 cases) to 43.8% (39,417 in 90,032 cases) for CT and from 8.9% (1,316 in 14,791 cases) to 15.7% (6,083 in 38,865 cases) for MR. The average time spent on interpreting each diagnostic image decreased significantly from 16.0 to 2.9 sec. (P < 0.001). CONCLUSION: Imaging utilization increased significantly under the NHI system at a medical centre. The corresponding demand for image interpretation also placed a significant workload on radiologists, potentially contributing to radiologist burnout.

Clinical implications of airway anomalies and stenosis in patients with heterotaxy syndrome.

In heterotaxy syndrome, bronchopulmonary situs usually reflects atrial situs, resulting in either right (RAI) or left atrial isomerism (LAI). This study determines airway anomalies and its implications in patients with heterotaxy. This retrospective study included 223 patients with heterotaxy syndrome who received an integrated cardiac computed tomography evaluation. Patient database from 1995 to 2020 was reviewed. The patients were examined by a congenital heart disease team comprising pediatric cardiologists, radiologists, pulmonologists, and cardiovascular surgeons. Among the 223 patients, 189 (84.8%, M/F = 1.66) had RAI and 29 had LAI (13.0%, M/F = 0.71). Five patients had indeterminate isomerism (2.2%, M/F = 1.5). Discordant bronchopulmonary and atrial situs occurred in 4% patients, while discordant bronchopulmonary, atrial, and splenic situs occurred in 23.2% patients. Lower airway stenosis was observed in 61 patients (27.4%), including 27.5%, 20.7%, and 60% RAI, LAI, and indeterminate isomerism patients, respectively (p = 0.189). One patient had an intrinsic long segment lower tracheal stenosis and received slide tracheoplasty. Initial cardiac operation was performed in 213 patients. Higher surgical mortality occurred in patients with RAI (19.5% vs. none for LAI and indeterminate isomerism, p = 0.038). In patients with RAI, lower airway anomaly/stenosis increased the duration of ventilator usage (p = 0.030) but did not affect surgical mortality. Total anomalous pulmonary venous return to systemic veins and pulmonary venous stenosis were major surgical risk factors. Bronchopulmonary isomerism shares a similar isomeric pattern to cardiac atrial appendage. Lower airway anomalies/stenosis was common in patients with heterotaxy, resulting in prolonged ventilator therapy in patients with RAI.

Clinical implications of congenital interruption of inferior vena cava.

BACKGROUND/PURPOSE: Inferior vena cava (IVC) interruption is rare and can be detected through prenatal or postnatal imaging. It usually occurs in patients with heterotaxy syndrome with bilateral left-sidedness (left isomerism or polysplenia syndrome), indicating a laterality defect. However, its long-term outcomes remain unclear. METHODS: This retrospective study included a patient cohort with evidence of IVC interruption based on imagining data (1980-2019) selected from our institutional database. RESULTS: We included 34 (male/female = 14/20) patients with IVC interruption. Most of the patients had left isomerism of the bronchopulmonary situs (96.4%) and cardiac atrial situs (90.3%). Splenic anomalies, including polysplenia (35.7%), lobulated spleen (39.3%), inversus solitary spleen (10.7%), and asplenia (3.6%), were common. Normal cardiac structure was noted in four (11.8%) patients. Congenital heart disease (CHD) was noted in 30 patients: 7 with simple CHD and 23 with severe CHD. Bradycardia occurred in 47.1% of the patients and was not associated with CHD. Splenic variations were not associated with CHD or bradycardia. The survival rates for the 10-, 20-, and 40-year age groups were 0.880, 0.792, and 0.441, respectively; severe CHD was the only risk factor. CONCLUSION: IVC interruption can present as an isolated lesion and be associated with CHD. Although bradycardia was common among the patients, CHD severity was the only risk factor for survival. Patients with IVC interruption commonly have left isomerism at the atrial and bronchopulmonary situs, but the spectrum of splenic abnormalities is wide, including polysplenia, lobulated spleen, solitary inversus spleen, and, rarely, asplenia.

Pediatric Cardiothoracic CT Guideline Provided by the Asian Society of Cardiovascular Imaging Congenital Heart Disease Study Group: Part 2. Contemporary Clinical Applications.

The use of pediatric cardiothoracic CT for congenital heart disease (CHD) was traditionally limited to the morphologic evaluation of the extracardiac thoracic vessels, lungs, and airways. Currently, the applications of CT have increased, owing to technological advancements in hardware and software as well as several dose-reduction measures. In the previously published part 1 of the guideline by the Asian Society of Cardiovascular Imaging Congenital Heart Disease Study Group, we reviewed the prerequisite technical knowledge for clinical applications in a user-friendly and vendor-specific manner. Herein, we present the second part of our guideline on contemporary clinical applications of pediatric cardiothoracic CT for CHD based on the consensus of experts from the Asian Society of Cardiovascular Imaging CHD Study Group. This guideline describes up-to-date clinical applications effectively in a systematic fashion.

History of the Asian Society of Cardiovascular Imaging.

The Asian Society of Cardiovascular Imaging (ASCI) was established in 2006 to improve the healthcare, education, training, quality control, and research in cardiovascular imaging in Asia. The ASCI is presently active, with more than 1400 members from 53 countries. Herein, the evolution and current development of the ASCI are described, including the early history, organization, annual congresses, collaboration with international sister societies, official journal, and the ASCI School. The ASCI has successfully led the development of cardiovascular imaging in Asia and will continue to grow.

Prognostic markers in patients undergoing transcatheter implantation of Venus P-valve: Experience in Taiwan.

BACKGROUND/PURPOSE: Prognostic factors remain unclear in patients undergoing transcatheter implantation of Venus P-valve for their severe pulmonary regurgitation associated with native right ventricular (RV) outflow tract. METHOD: Between January 2017 and October 2018, we prospectively collected data of patient characteristics, cardiac magnetic resonance imaging, cardiopulmonary exercise testing, and levels of N-terminal pro-B-type natriuretic peptide (NT-proBNP) before and 6-12 months after valve graft implantation. RESULTS: Fifteen patients (male: 8, median age: 24.8 years) were enrolled. The procedure success rate was 100%. The median follow-up was 16.3 months without any dysfunction of the valve graft. The cohort demonstrated a significant improvement in cardiac index (from 3.3 to 3.9 L/min/m2) and increase of percentage of New York Heart Association functional class I (P < 10-3), reduction in RV end-diastolic volume index (P = 0.008), and reductions in NT-proBNP levels (from 78.9 to 45.8 pg/mL, P = 0.040). However, the peak oxygen consumption (VO2) dropped from 50.2% to 48.5% of the predicted value. Interestingly, we determined that patients with NT-proBNP levels below 70 pg/mL and left ventricular end-diastolic pressure (LVEDP) below 11 mmHg had a significantly higher chance of exhibiting improvement in peak VO2 compared with those without (3/4 vs 1/10, P = 0.041). CONCLUSION: In the small cohort with severe pulmonary regurgitation, implantation of a Venus P-valve led to promising reductions in RV volume. However, no definite improvement in cardiopulmonary exercise capacity or RV ejection fraction was achieved. Levels of NT-proBNP and LVEDP may be helpful for refining the indications of the Venus P-valve implantation.

The Third Asian Radiology Forum: Screening Programs in Asia.

According to reports presented at the Asian Radiology Forum 2017 in Taipei, the landscape of screening in Asia is growing, and the role of radiologists is also evolving. The Asian Radiology Forum was first held by the Korean Society of Radiology and the national delegates of Asian radiological partner societies, who attended this meeting with the aim of discussing selected subjects of global relevance in radiology. In 2017, current trends and policies concerning various cancer screening programs from each delegate country were discussed. Various screening programs were discussed, including liver screening in Thailand, thyroid cancer screening in Korea, and lung cancer screening data from the ongoing projects in Taiwan and Japan. The Asian Oceanian Society of Radiology could serve as a platform for international collaboration, and educational exchange between member societies was also highlighted in the forum. Most Asian radiology societies are looking forward to an expansion in the scale of international collaboration and for the provision of additional exchange programs in the future.

Diagnosis of Pulmonary Arterial Hypertension in Children by Using Cardiac Computed Tomography.

OBJECTIVE: To establish diagnostic criteria for pulmonary arterial hypertension (PAH) in children by using parameters obtained through noninvasive cardiac computed tomography (CCT). MATERIALS AND METHODS: We retrospectively measured parameters from CCT images of children from a single institution in a multiple stepwise process. A total of 208 children with mean age of 10.5 years (range: 4 days-18.9 years) were assessed. The variables were classified into three groups: the great arteries; the ventricular walls; and the bilateral ventricular cavities. The relationship between the parameters obtained from the CCT images and mean pulmonary arterial pressure (mPAP) was tested and adjusted by the children's body size. Reference curves for the pulmonary trunk diameter (PTD) and ratio of diameter of pulmonary trunk to ascending aorta (rPTAo) of children with CCT images of normal hearts, adjusted for height, were plotted. Threshold lines were established on the reference curves. RESULTS: PTD and rPTAo on the CCT images were significantly positively correlated with mPAP (r > 0.85, p < 0.01). Height was the body size parameter most correlated with PTD (r = 0.91, p < 0.01) and rPTAo (r = -0.69, p < 0.01). On the basis of the threshold lines on the reference curves, PTD and rPTAo both showed 88.9% sensitivity for PAH diagnosis, with negative predictive values of 93.3% and 92.9%, respectively. CONCLUSION: PTD and rPTAo measured from CCT images were significantly correlated with mPAP in children. Reference curves and the formula of PTD and rPTAo adjusted for height could be practical for diagnosing PAH in children.

Excessive Tracheal Length in Patients With Congenital Tracheal Stenosis.

BACKGROUND: Slide tracheoplasty is the preferred approach for treating long-segment congenital tracheal stenosis (CTS). However, little research has been conducted on the tracheobronchial anatomy before and after slide tracheoplasties in patients with CTS. METHODS: We reviewed 23 patients with CTS who received slide tracheoplasties. We measured the intrathoracic tracheal length and the carina angle from computed tomography images. To account for each patient's body size, we divided the intrathoracic tracheal length by the length of the thorax to obtain the trachea-thorax ratio (TTR). These measurements were used to compare patients before and after slide tracheoplasties as well as normal control subjects. RESULTS: Two patients had upper tracheal CTS and 21 patients had lower tracheal CTS. For the 21 patients with lower tracheal stenosis, their TTRs before slide tracheoplasty were 0.42 ± 0.04, which were significantly larger than those of the control subjects (0.32 ± 0.04; p < 0.0001). After slide tracheoplasty, the TTR was 0.32 ± 0.04, similar to the control TTRs (p = 0.94). The carina angle was significantly wider in the 21 patients than in the control subjects (120.7 ± 11.7 degrees versus 86.4 ± 13.1 degrees; p < 0.0001). After slide tracheoplasty, the carina angle was significantly narrower (from 120.7 ± 11.7 degrees to 92.2 ± 15.2 degrees; p < 0.0001), which was similar to control subjects. CONCLUSIONS: The trachea was longer and the carina angle wider in patients with lower tracheal CTS than in control subjects. Excessive tracheal length is favorable for slide tracheoplasty. Slide tracheoplasty not only corrects CTS, but also restores tracheobronchial morphology.

Arterial Switch, Ventricular Septation, and Fontan Takedown for Double Inlet Left Ventricle.

A patient with double inlet left ventricle with transposition of great arteries and severe coarctation of the aorta received aortoplasty and pulmonary artery banding, followed by bidirectional Glenn shunt and extracardiac total cavopulmonary connection (TCPC). Severe subaortic stenosis and increased atrioventricular valve regurgitation were noted 4 years after TCPC. Surgery included alleviation of the subaortic stenosis, ventricular septation through the tricuspid valve approach, and an arterial switch with the main pulmonary artery reopened. The TCPC was taken down with both caval veins reconnected to the right atrium; the neopulmonary artery was reconstructed. Biventricular conversion from TCPC was achieved.

Computed tomography predict regression of coronary artery aneurysm in patients with Kawasaki disease.

BACKGROUND/PURPOSE: The study evaluated possible factors influencing the regression of coronary artery aneurysm (CAA) in patients with Kawasaki disease (KD) through electrocardiographically gated cardiac computed tomography (CT). METHODS: 18 patients with KD exhibited CAAs in at least 2 CT examinations conducted from December 2004 to September 2015, and 37 aneurysms were observed. Every aneurysm was corrected through the descending aorta at the origin level of the left main coronary artery under a normal distribution and measured under a fixed window level. These aneurysms were divided into 2 groups according to regression. Clinical symptoms, laboratory data, and imaging characteristics of both groups were analyzed. RESULTS: All the aneurysms of 4 patients decreased in size, and totally, 14 aneurysms (37%) regressed. CAA regression tends to occur early after disease onset. No significant differences were observed in sex, aneurysm location, and the distance to the orifice between the 2 groups. The aneurysms with no calcification (p = 0.012), smaller diameter (p = 0.004), younger disease onset age (p = 0.048), and ectatic shape (p < 0.001) were more likely to regress according to univariate analysis. Receiver operating characteristic analysis revealed that the possible cut-off point of the maximal diameter to yield the highest sensitivity (91.3%) and specificity (92.9%) to predict CAA regression was 5.6 mm. CONCLUSION: Calcified CAAs in patients with KD was less likely to regress. The aneurysm size and shape as well as disease onset age were possible factors influencing regression.

Surgical Correction for a Neonate With Ebstein's Anomaly Associated With Tetralogy of Fallot.

Ebstein's anomaly in combination with tetralogy of Fallot (TOF) is rare. We report a male infant with these combined anomalies who presented with severe cyanosis, heart failure, and respiratory distress after birth. Biventricular repair was successfully performed with 1-stage correction of his ventricular septal defect (VSD), right ventricular outflow tract (RVOT) obstruction, and tricuspid regurgitation. The downward displaced tricuspid valve was also restored to the normal annulus position. The infant recovered well. The surgical technique for this rare and severe anomaly is reported here.