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.

Multimodality diagnostic imaging for anomalous pulmonary venous connections: a pictorial essay.

Anomalous pulmonary venous connections represent a heterogeneous group of congenital heart diseases in which a part or all pulmonary venous flow drains directly or indirectly into the right atrium. Clinically, anomalous pulmonary venous connections may be silent or have variable consequences, including neonatal cyanosis, volume overload and pulmonary arterial hypertension due to the left-to-right shunt. Anomalous pulmonary venous connections are frequently associated with other congenital cardiac defects and their accurate diagnosis is crucial for treatment planning. Therefore, multimodality diagnostic imaging, comprising a combination (but not all) of echocardiography, cardiac catheterization, cardiothoracic computed tomography and cardiac magnetic resonance imaging, helps identify potential blind spots relevant to each imaging modality before treatment and achieve optimal management and monitoring. For the same reasons, diagnostic imaging evaluation using a multimodality fashion should be used after treatment. Finally, those interpreting the images should be familiar with the various surgical approaches used to repair anomalous pulmonary venous connections and the common postoperative complications.

Branch Pulmonary Artery Regurgitation in Repaired Tetralogy of Fallot: Correlation with Pulmonary Artery Morphology, Distensibility, and Right Ventricular Function.

BACKGROUND: The aim was to determine the effect of pulmonary artery (PA) morphology on the branch pulmonary artery-regurgitation fraction (BPA-RF), the relationship of pulmonary insufficiency (PI) to BPA-RF and PA-distensibility, and factors (BPA-RF and PA-distensibility) associated with right ventricular function (RVF) in repaired tetralogy of Fallot (rTOF). METHODS: A total of 182 rTOF patients (median age 17.1 years) were analyzed for length, angle of PA, BPA-RF, PI, and PA-distensibility, using magnetic resonance imaging. RESULTS: The left PA had a significant greater RF than the right PA (median (interquartile range)): LPA 43.1% (32.6-51.5) and RPA 35.2% (24.7-44.7), p < 0.001. The LPA was shorter with a narrower angle than the RPA (p < 0.001). The anatomy of the branch-PA was not a factor for the greater LPA-RF (odds ratio, 95% confidence interval: CI, p-value): length 0.44 (0.95-2.00), p = 0.28; angle 0.63 (0.13-2.99), p = 0.56. There was a strong positive correlation between PI and BPA-RF-coefficients (95% CI), p-value: LPA 0.78% (0.70-0.86), p < 0.001; RPA 0.78% (0.71-0.84), p < 0.001 and between BPA-RF and distensibility-coefficients (95%CI), p-value: LPA 0.73% (0.37-1.09), p < 0.001; RPA 1.63% (1.22-2.03), p < 0.001, respectively. The adjusted BPA-RF did not predict RVF, RPA (p = 0.434), LPA (p = 0.268). CONCLUSIONS: PA morphology is not a significant factor for the differential BPA-RF. The vascular wall in rTOF patients responds to chronic increased intravascular volume by increasing distensibility. BPA-RF is not a determinant of RVF.

Correlating computed tomographic angiography of pulmonary circulation with clinical course and disease burden in patients with tetralogy of Fallot and pulmonary atresia.

PURPOSE: To determine the type of pulmonary circulation (PC) in patients with tetralogy of Fallot (TOF) and pulmonary atresia (TOF-PA) with the use of computed tomographic angiography (CTA), and describe their clinical courses, corrective surgery and disease burden. METHODS: 145 patients (median age 4 years, interquartile range: IQR2-8 years) were analyzed for PC which divided into 5 CTA-types and 11 subtypes based on presence of main pulmonary trunk (MPA) and confluent pulmonary arteries (confluence-PAs), presence of ductus arteriosus or major aortopulmonary collateral arteries (MAPCAs), respectively. Pulmonary arteries (PAs) were assessed by McGoon ratio and arborization. Corrective surgery or palliative management was recorded by type of PC. Disease burden was calculated as the sum of CTA, diagnostic angiography, and palliative management. RESULTS: The most common (N = 77, 53 %) PC was the presence of MPA with confluent-PAs (type-1) which was encountered mostly in TOF patients, followed by the presence of confluent-PAs with atretic MPA (type-2) (N = 47, 32 %) which found mainly in TOF-PA. McGoon ratio in type-1 (2.44 ± 0.84) was significantly larger than type-2 (1.61 ± 0.61) (median difference 0.84, 95 %CI 0.56-1.11, p < 0.001). Almost 2/3 of patients in type-1 (71 %) and 1/3 of patients in type-2 (34 %) achieved corrective surgery. There was no significant difference in amount of disease burden among the different PC, with the median value of 3 (IQR1-4). CONCLUSIONS: Types of PC allow suggestions for size and arborization of PAs and successful surgical correction with an inverse relationship with the numbers of MAPCAs. There is no significant difference in amount of disease burden among the types of PC.

Coronary artery changes in congenital coronary-cameral fistulas evaluated by computed tomographic angiography.

PURPOSE: The study sought to determine coronary artery diameter in congenital coronary-cameral fistula (cCCF), factors associated with coronary artery aneurysm, coronary artery changes after fistula closure, and computed tomographic (CT) findings after treatment. MATERIALS AND METHODS: We retrospectively reviewed CT findings of the cCCF for origins, terminations, fistula length, complexities, and Sakakibara classification. Coronary artery diameter was expressed as coronary artery Z score. Fistula features associated with coronary artery aneurysm were analyzed. Post-fistula closures were analyzed for coronary artery dilatation, coronary thrombosis, complete fistula closure, and fistula thrombosis. RESULTS: Twenty-five patients (median age 33 months, interquartile range, IQR 25-48) were included. Coronary feeders and terminations were frequently right coronary artery (48%) and right ventricle (56%), respectively. Fistula aneurysm occurred in 52% of cases. Mean coronary artery Z score was 13.03 ± 6.36 with a high incidence of giant coronary artery aneurysm (68%). We found no statistically significant risk factors associated with coronary artery aneurysm (p value range 0.075-0.370). Median duration of the follow-up CT after closure of the fistulas was 6.4 months (IQR 5.0-8.7). Coronary artery Z score significantly decreased by 0.82 (IQR 0.28-1.35), p = 0.006 and coronary thrombosis occurred in 23% of cases during follow-up. CONCLUSIONS: Large coronary aneurysm is common in cCCF. No characteristic feature of the fistula influencing coronary artery aneurysm is identified. There is a diminution in coronary artery Z score after fistula closure. Coronary thrombosis is a major complication after treatment.

Follow-up aortic dilatation in patients with repaired tetralogy of Fallot using cardiovascular magnetic resonance.

PURPOSE: The study sought to determine the rate of aortic expansion and correlation with somatic growth in patients with repaired tetralogy of Fallot (rTOF), and predictors for determining the annual growth rate of the aorta (Ao-AGR). METHODS: Ninety-four rTOF patients (mean age 14.5 ± 4.4 years) with two cardiac magnetic resonance tests (CMR) (median duration 52 months, interquartile range, IQR 24-71) were analyzed for aortic diameter (AoD) at the annulus, the sinus of Valsalva (SoV), the sinotubular junction, and the ascending aorta (AAo), and compared with the normal limit AoD (NL-AoD) values. The median age-at-repair was 60 months (IQR 36-84). Ao-AGR and its index (Ao-AGRI) were derived from changes of the AoD and AoD-index, respectively, divided by the duration between the two studies. Three potential predictors (baseline AoD, sex, and age-at-repair) for the progression of Ao-AGR were analyzed. RESULTS: There was a significant larger AoD than NL-AoD (p < 0.001). Slow aortic growth was encountered in 78-85 % of patients. The Ao-AGR was slow, the median AGR ranged from 0.37 mm (IQR 0.13-0.72) at annulus to 0.56 mm (IQR 0.22-0.91) at AAo. There was a regression in Ao-AGRI, ranged from -1.41 mm (IQR -1.94, -0.87) at annulus to -2.36 mm (IQR -3.09, -1.63) at SoV. The three predictors were not correlated with severity of Ao-AGR. CONCLUSION: Most adolescents with rTOF show significant aortic dilatation. There is a slow Ao-AGR with regression of Ao-AGRI, which may suggest that the rate of aortic growth is slower than the somatic growth. There are no significant predictors of the progression of Ao-AGR.

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.

Magnetic resonance imaging assessment of aortic dilatation and distensibility in 269 patients with repaired tetralogy of Fallot.

PURPOSE: To determine the prevalence and degree of aortic dilatation (Adilatation), severity of aortic stiffness (Astiff), factors for Adilatation, and level of aortic root most sensitive to Astiff in patients with repaired tetralogy of Fallot (rTOF). MATERIALS AND METHODS: 269 patients with rTOF (mean age 14.9 ± standard deviation 5.0 years) were analyzed for Adilatation at annulus, sinus, sinotubular junction, and ascending aorta (aAo). Aortic size index was graded as Z score < 2, 2-2.99, 3-4.99 and ≥ 5. Aortic distensibility (aAdis) was categorized according to 4 aortic levels and dilatation severity. Factors for Adilatation and level of aortic root most sensitive to Astiff were analyzed. RESULTS: Sinus and aAo were the two most common sites of Adilatation, with a prevalence of 84% and 76%, respectively. A decreased aAdis was found (mean 5.38 ± 1.79 10-3 mmHg-1). aAdis only declined significantly at the sinus level (p = 0.009). Male sex, age-at-repair and aortic regurgitation were significant factors for Adilatation, with male sex as the strongest factor (odds ratio 2.94). There was a significant decline in aAdis at sinus level (p = 0.002) as Adilatation progressed. CONCLUSIONS: We observed a high prevalence of Adilatation and Astiff in patients with rTOF. Male sex is the strongest factor for Adilatation. The sinus is the most sensitive area for determining a negative aAdis effect.

CT and MRI for Repaired Complex Adult Congenital Heart Diseases.

An increasing number of adult congenital heart disease (ACHD) patients continue to require life-long diagnostic imaging surveillance using cardiac CT and MRI. These patients typically exhibit a large spectrum of unique anatomical and functional changes resulting from either single- or multi-stage palliation and surgical correction. Radiologists involved in the diagnostic task of monitoring treatment effects and detecting potential complications should be familiar with common cardiac CT and MRI findings observed in patients with repaired complex ACHD. This review article highlights the contemporary role of CT and MRI in three commonly encountered repaired ACHD: repaired tetralogy of Fallot, transposition of the great arteries after arterial switch operation, and functional single ventricle after Fontan operation.

Prevalence and predictors of cardiac and liver iron overload in patients with thalassemia: A multicenter study based on real-world data.

Prevalence of cardiac and liver iron overload in patients with thalassemia in real-world practice may vary among different regions especially in the era of widely-used iron chelation therapy. The aim of this study was to determine the prevalence of cardiac and liver iron overload in and the management patterns of patients with thalassemia in real-world practice in Thailand. We established a multicenter registry for patients with thalassemia who underwent magnetic resonance imaging (MRI) as part of their clinical evaluation. All enrolled patients underwent cardiac and liver MRI for assessment of iron overload. There were a total of 405 patients enrolled in this study. The mean age of patients was 18.8±12.5years and 46.7% were male. Two hundred ninety-six (73.1%) of patients received regular blood transfusion. Prevalence of cardiac iron overload (CIO) and liver iron overload (LIO) was 5.2% and 56.8%, respectively. Independent predictors for iron overload from laboratory information were serum ferritin and transaminase for both CIO and LIO. Serum ferritin can be used as a screening tool to rule-out CIO and to diagnose LIO. Iron chelation therapy was given in 74.6%; 15.3% as a combination therapy.

Asian consortium on radiation dose of pediatric cardiac CT (ASCI-REDCARD).

BACKGROUND: With incremental utilization of pediatric cardiac CT in congenital heart disease, it is imperative to define its current radiation dose levels in clinical practice in order to help imagers optimize CT protocols, particularly in Asia and other developing countries where CT physicists are not readily available. OBJECTIVE: To evaluate current radiation dose levels and influencing factors in cardiac CT in children with congenital heart disease in Asia by conducting a retrospective multi-center, multi-vendor study. MATERIALS AND METHODS: We included 1,043 pediatric cardiac CT examinations performed in 8 centers between January 2014 and December 2014 to evaluate congenital heart disease. In five weight groups, we calculated radiation dose metrics including volume CT dose index, size-specific dose estimate, dose-length product and effective dose. Age at CT exam, gender, tube voltage, scan mode, CT indication and image reconstruction algorithm were analyzed to learn whether they influenced CT radiation dose. RESULTS: Volume CT dose index, size-specific dose estimate, dose-length product and effective dose of pediatric cardiac CT showed variations in the range of 4.3-23.8 mGy, 4.9-17.6 mGy, 55.8-501.3 mGy∙cm and 1.5-3.2 mSv, respectively, within five weight groups. Gender, tube voltage, scan mode and cardiac function assessment significantly influenced CT radiation dose. CONCLUSION: This multi-center, multi-vendor study demonstrated variations in radiation dose metrics of pediatric cardiac CT reflecting current practice in Asia. Gender, tube voltage, scan mode and cardiac function assessment should be considered as essential radiation dose-influencing factors in developing optimal pediatric cardiac CT protocols.

Percutaneous pulmonary valve implantation with the Venus P-valve: clinical experience and early results.

BACKGROUND: At present, the exclusion for percutaneous pulmonary valve implantation for free pulmonary regurgitation after tetralogy of Fallot repair includes an unfavourably large right ventricular outflow tract. OBJECTIVE: To report feasibility and early experience with a recently developed transcatheter heart valve, Venus P-valveTM, implanted in six patients with severe pulmonary regurgitation with large right ventricular outflow tracts. Patients There were two female patients and four male patients. The median age of the patients was 18.5 years, and the mean body weight was 53.8 kg. All the patients were in NYHA class II and had severe pulmonary regurgitation after previous transannular patch repair of tetralogy of Fallot. The median time after the last surgical operation was 13.5 years. RESULTS: The Venus P-valveTM was successfully implanted in all the patients with implanted valve diameters ranging from 24 to 32 mm. The mean fluoroscopy time was 29.8 minutes. None of the patients had significant outflow tract gradient or pulmonary regurgitation immediately after valve implantation. Only one patient had unexpected mild proximal valve migration to the right ventricular body during withdrawal of the delivery system. It caused mild paravalvar leak and significant tricuspid regurgitation. At 6 months follow-up, the median of right ventricular end-diastolic volume indices decreased from 146 to 108 ml/m2 (p-value=0.046). The Doppler systolic peak gradient across the valve ranged from 4 to 40 mmHg, and there was no evidence of stent fracture on fluoroscopy or structural valve failure. CONCLUSION: The Venus P-valveTM can be implanted successfully and effectively in patients with severe pulmonary regurgitation and a large right ventricular outflow tract. The early results with this valve are encouraging.

Visibility and variability of pleural fissures on normal digital chest radiographs of 1,000 healthy adults.

PURPOSE: To investigate the visibility and variability of pleural fissures on digital chest radiographs. METHODS: Posteroanterior digital chest radiographs of 566 males and 434 females were retrospectively reviewed for the frequencies and/or appearances of various pleural fissures. RESULTS: The right only, left only and bilateral minor fissures were visible in 722 (72.2 %), 1 (0.1 %) and 7 (0.7 %) subjects, respectively. The right minor fissures were visible as more than one line in 219 (30.0 %) subjects, i.e., 2, 3 and 4 lines in 214 (29.3 %), 4 (0.5 %) and 1 (0.1 %), respectively. The 955 visible right minor fissures exhibited variable length (<1/3 of right hemithorax, 17.8 %; 1/3-2/3, 60.1 %; >2/3, 22.1 %), alignment (medial higher 40.9 %; lateral higher 54.2 %; horizontal 4.8 %) and contour (convex upward 68.6 %; convex downward 2.7 %; flat 24.9 %; sigmoid 3.8 %). Superolateral major fissures were visualized in 14.8 % (right only 3.0 %; left only 9.0 %; bilateral 2.8 %), superomedial major fissures in 0.3 % (right 0.1 %; left 0.2 %), vertical fissures in 0.5 % (right 0.2 %; left 0.3 %), inferior accessory fissures in 5.4 % (right 4.8 %; left 0.6 %), right superior accessory fissures in 1.2 % and azygos fissures in 0.2 %. CONCLUSION: The right minor fissure was most frequently visible and exhibited variable appearances. Other pleural fissures were occasionally seen.

A comparative study: right ventricular assessment in post-repaired tetralogy of Fallot patients by echocardiogram with cardiac magnetic resonance imaging.

BACKGROUND: Post-repaired Tetralogy of Fallot (TOF) patients require comprehensive evaluation of the right ventricular (RV) size and function. Currently, cardiac magnetic resonance imaging (CMR) is considered to be the gold standard for RV function assessment. Echocardiogram (ECHO) is the most useful non-invasive tool for RV assessment. However, correlations of ECHO and CMR findings for this particular group of patients require further evaluation. OBJECTIVE: The first objective is to assess the correlation between RV size/function, measured by ECHO and CMR. The second objective is to investigate ECHO parameters that correlate best with RV end diastolic volume index (RVEDVi) of 160 mL/m2 from CMR. MATERIAL AND METHOD: The present study recruited 20 TOF patients (mean age 14 ± 2 years) who underwent right ventricular outflow tract reconstruction and/or pulmonary valve replacement for at least 5 years, from June 2011 to March 2012. The RV was initially evaluated with CMR, followed by ECHO within 3 months. ECHO parameters measured were tricuspid annular plane systolic excursion (TAPSE), fractional area change (FAC), area of right ventricular end diastole index (area RVEDi), RV free wall myocardial performance index (RVMPI), and qualitative assessment of pulmonary valve regurgitation (PR). All ECHO parameters were compared with CMR measurements of right ventricular ejection fraction (RVEF), RVEDVi and quantitative assessment of PR. Comparative analysis were assessed by Pearson's sample correlation coefficient, Kappa, and sensitivity and specificity of RVEDi area from ROC curve analysis. RESULTS: Results showed significant correlations between RVEDVi and area RVEDi (R = 0.768, p < 0.01), RVEF with FAC (R = 0.759, p < 0.01), and RVEF with TAPSE (R = 0.688, p < 0.01). Hundred percent correlation was found in moderate to severe PR assessment by ECHO and CMR (Kappa = 0.912). Abnormal RVMPI was not correlated with NYHA FC, CXR and ECG (Kappa = -0.10, 0.15, -0.04). The area RVEDi ≥ 20.43 cm2/m2 correlated well with RVEDVi ≥ 160 mL/m2 (sensitivity 64%, specificity 83%) from ROC curve analysis. CONCLUSION: ECHO is an effective tool for RV evaluation in post-repaired TOF with PR. FAC, TAPSE and severity of PR from ECHO correlated well with CMR parameters. Measurement of area RVEDi from ECHO is the best parameter to predict RVEDVi from CMR.

Cardiac CT angiography in children with congenital heart disease.

Cardiac imaging plays an important role in both congenital and acquired heart diseases. Cardiac computed tomography (angiography) cCT(A) is a non-invasive, increasingly popular, complementary modality to echocardiography in evaluation of congenital heart diseases (CHD) in children. Despite radiation exposure, cCT(A) is now commonly used for evaluation of the complex CHD, giving information of both intra-cardiac and extra-cardiac anatomy, coronary arteries, and vascular structures. This review article will focus on the fundamentals and essentials for performing cCT(A) in children, including radiation dose awareness, basic techniques, and strengths and weaknesses of cCT(A) compared with cardiac magnetic resonance imaging (cMRI), and applications. The limitations of this modality will also be discussed, including the CHD for which cMRI may be substituted.

Pulmonary atresia and ventricular septal defect with collaterals to right lung associated with anomalous left pulmonary artery from the ascending aorta.

We present a 10-month-old boy with cyanosis. This is a rare case of pulmonary atresia, ventricular septal defect (VSD), major aorto-pulmonary collateral arteries (MAPCAs) to the right lung with absent native right pulmonary artery (RPA) in association with anomalous left pulmonary artery (LPA) from the ascending aorta (AAo). Echocardiography was unable to identify all of the cardiovascular abnormalities. Multidetector CT demonstrated all of these abnormalities and is the investigation of choice instead of cardiac catheterization.

Transcoronary bone marrow-derived progenitor cells in a child with myocardial infarction: first pediatric experience.

BACKGROUND: Recent advances in stem cell therapy to restore cardiac function have great promise for patients with congestive heart failure after myocardial infarction in an adult population. OBJECTIVE: We examined the benefits of bone marrow-derived progenitor cells treatment modality for the pediatric patient. METHODS AND RESULTS: We present our first case of transcoronary autologous stem cell transplantation in a 9-year-old girl with refractory congestive heart failure secondary to myocardial infarction 1 year after transcatheter revascularization. The child received daily injections of granulocyte colony-stimulating factor for 3 days prior to the bone marrow aspiration. The bone marrow cells were isolated to constitute CD133+/CD34+ more than 90% of the total number. Subsequently, the progenitor cell suspension was injected via a transcoronary catheter without any complication. Three months after stem cell therapy, her cardiac function, assessed by both cardiac magnetic resonance and echocardiogram, has been improved with the left ventricular ejection fraction at 47% compared to the baseline of 30%. CONCLUSION: This is the first reported pediatric case of successful transcoronary injection of bone marrow-derived progenitor cells for end-stage heart disease. The procedure is considered safe and feasible for the pediatric population.

Hepatocellular adenoma: a case report.

A case of hepatocellular adenoma (HCA) was described in a 26-year-old woman, who was a potential kidney donor for her father and denied taking the oral contraceptive pill. A hypervascular mass of 4.1 cm in largest dimension was detected in the liver segment V by computerized tomography and magnetic resonance imaging (MRI). The normal levels of liver enzymes, negative serum markers for hepatitis viruses, and non-elevated alpha- fetoprotein level were detected. The wedge resection of segment V was done with an uneventful clinical course. In Western countries, HCAs are known to occur in women in their reproductive periods. It may not be associated with oral contraceptive. Molecular biological studies disclosed three variants of HCAs, i.e., I) with mutation of HNF 1-alpha gene, II) with mutation of beta-catenin gene, and III) no mutation of the two genes. Histological correlations with the three variants as recommended by the Bordeaux group in 2007 could not be accomplished in the present study due to overlapping histological features between the variants I and III. The etiological factors of HCA are known to relate to the contraceptive pill usage in female and the anabolic-androgenic-steroid administration in male. In Thailand, the occurrence of HCA is expected to be only 0.3% of cases with hepatocellular carcinoma.