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

Trends in cardiac CT utilization for patients with pediatric and congenital heart disease: A multicenter survey study

BACKGROUND

The use of cardiac CT (CCT) has increased dramatically in recent years among patients with pediatric and congenital heart disease (CHD), but little is known about trends and practice pattern variation in CCT utilization for this population among centers.

METHODS

A 21-item survey was created to assess CCT utilization in the pediatric/CHD population in calendar years 2011 and 2021. The survey was sent to all non-invasive cardiac imaging directors of pediatric cardiology centers in North America in September 2022.

RESULTS

Forty-one centers completed the survey. In 2021, 98% of centers performed CCT in pediatric and CHD patients (vs. 73% in 2011), and 61% of centers performed >100 CCTs annually (vs. 5% in 2011). While 62% of centers in 2021 utilized dual-source technology for high-pitch helical acquisition, 15% of centers reported primarily performing CCT on a 64-slice scanner. Anesthesia utilization, use of medications for heart rate control, and type of subspecialty training for physicians interpreting CCT varied widely among centers. 50% of centers reported barriers to CCT performance, with the most commonly cited concerns being radiation exposure, the need for anesthesia, and limited CT scan staffing or machine access. 37% (11/30) of centers with a pediatric cardiology fellowship program offer no clinical or didactic CCT training for categorical fellows.

CONCLUSION

While CCT usage in the CHD/pediatric population has risen significantly in the past decade, there is broad center variability in CCT acquisition techniques, staffing, workflow, and utilization. Potential areas for improvement include expanding CT scanner access and staffing, formal CCT education for pediatric cardiology fellows, and increasing utilization of existing technological advances.

Multimodality Imaging Assessment of Tetralogy of Fallot: From Diagnosis to Long-Term Follow-Up

Tetralogy of Fallot (TOF) is the most common complex congenital heart disease with long-term survivors, demanding serial monitoring of the possible complications that can be encountered from the diagnosis to long-term follow-up. Cardiovascular imaging is key in the diagnosis and serial assessment of TOF patients, guiding patients' management and providing prognostic information. Thorough knowledge of the pathophysiology and expected sequalae in TOF, as well as the advantages and limitations of different non-invasive imaging modalities that can be used for diagnosis and follow-up, is the key to ensuring optimal management of patients with TOF. The aim of this manuscript is to provide a comprehensive overview of the role of each modality and common protocols used in clinical practice in the assessment of TOF patients.

320 cardiac MDCT angiography in preoperative assessment of TOF and its variants: Does it worth it?

Background

Tetralogy of Fallot is the most common cyanotic congenital heart disease encountering a large spectrum of anatomical presentations with differing surgical approaches, and long-term outcomes ranging from ventricular septal defect with limited aortic overriding and mild pulmonary obstruction to a critical form of VSD and pulmonary atresia. TOF variants include PA/VSD, TOF/CAVC, TOF/DORV and TOF with absent pulmonary valve. Also, it may be accompanied with many associated intracardiac and extracardiac anomalies that may be of value when imaging and planning the surgical procedure.

Results

Our study included 22 cases of classic TOF, 18 with PA/VSD (12 were of type A, 5 were of type B and 1 was of type C), 3 with TOF/CAVC and 7 TOF/DORV. Sub-valvular RVOTO was detected in 94% of patients. A statistically significant difference was depicted between Echocardiography and MDCT in detecting supravalvular RVOTO, however no statistically significant difference was found in sub-valvular and valvular RVOTO detection. MDCT could efficiently characterize pulmonary arterial tree with statistically significant difference between both Echocardiography and MDCT in assessment of main, right and left pulmonary arteries with P value = 0.036,0.014 and 0.023 respectively. With calculation of Mc-Goon ratio in all patients, it was favorable (> 1.2) in 33 patients (66%). MDCT entailed 19 patients with PDA versus 15 depicted by Echocardiography and 25 MAPCAs per 11patients compared 8 MAPCAs per 7 patients detected by Echocardiography. Right sided aortic arch was found in 10 patients and 24 patients showed abnormal branching pattern. Coronary artery abnormalities were identified in eight patients. MDCT showed 100% sensitivity and 100% specificity in depicting aortic, coronary and other associated extracardiac vascular anomalies.

Conclusion

MDCT offers comprehensive anatomical assessment of TOF, and its variants providing superiority over echocardiography and comparable results to cardiac catherization with 100% sensitivity and specificity in evaluation of associated extracardiac vascular anomalies as well as pulmonary arteries characterization. It is worth using MDCT routinely in combination with echocardiography for the preoperative assessment of TOF and its variants representing a less invasive option than conventional catherization with lower radiation exposure.

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.

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

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

Feasibility and utility of dual-energy chest CTA for preoperative planning in pediatric pulmonary artery reconstruction

The purpose of this study was to assess in pediatric pulmonary artery (PA) reconstruction candidates the feasibility and added utility of preoperative chest computed tomography angiography (CTA) using dual-energy technique, from which perfused blood volume (PBV)/iodine maps can be generated as a surrogate of pulmonary perfusion. Pediatric PA reconstruction patients were prospectively recruited for a new dose-neutral dual-energy CTA protocol. For each case, the severity of anatomic PA obstruction was graded by two pediatric cardiovascular radiologists in consensus using a modified Qanadli index. PBV maps were qualitatively reviewed and auto-segmented using Siemens syngo.via software. Associations between Qanadli scores and PBV were assessed with Spearman correlation (r) and ROC analysis. Effective radiation doses were estimated from dose-length product and ICRP 103 k-factors, using cubic Hermite spline interpolation. 19 patients were recruited with mean (SD) age of 6.0 (5.1), 11 (57.9%) female, 11 (73.7%) anesthetized. Higher QS correlated with lower PBV, both on a whole lung (r =  - 0.54, p < 0.001) and lobar (r =  - 0.50, p < 0.001) basis. The lung with lowest absolute PBV was predictive of the lung with highest Qanadli score, with AUC of 0.70 (95% CI 0.47-0.93). Qualitatively, PBV maps were heterogeneous, corresponding to multifocal PA stenoses, with decreased iodine content in areas of most severe obstruction. In conclusion, dual-energy chest CTA is feasible for pediatric PA reconstruction candidates. PBV maps show deficits in regions of more severe anatomic obstruction and may serve as a novel biomarker in this population.

Isolated Major Aortopulmonary Collateral as the Sole Pulmonary Blood Supply to an Entire Lung Segment

Congenital systemic-to-pulmonary collateral arteries or major aortopulmonary collaterals are associated with cyanotic congenital heart disease with decreased pulmonary blood flow. Though it is usually associated with congenital heart diseases, there is an increased incidence of isolated acquired aortopulmonary collaterals in premature infants with chronic lung disease. Interestingly, isolated congenital aortopulmonary collaterals can occur without any lung disease, which may cause congestive heart failure and require closure. We present a neonate with an echocardiogram that showed only left-sided heart dilation. Further workup with a CT angiogram demonstrated an anomalous systemic artery from the descending thoracic aorta supplying the left lower lobe. He eventually developed heart failure symptoms and was taken to the catheterization laboratory for closure of the collateral. However, with the collateral being the only source of blood flow to the entire left lower lobe, he required surgical unifocalization. Isolated aortopulmonary collaterals without any other congenital heart disease or lung disease are rare. Our patient is the first reported case to have an isolated aortopulmonary collateral being the sole pulmonary blood supply to an entire lung segment. Due to its rarity, there is still much to learn about the origin and development of these collaterals that possibly developed prenatally.

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

Objective

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

Methods

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

Results

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

Conclusion

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

An Overview of Pulmonary Atresia and Major Aortopulmonary Collateral Arteries

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