Cardiac magnetic resonance predictors for successful primary biventricular repair of unbalanced complete common atrioventricular canal.

BACKGROUND: Patients with unbalanced common atrioventricular canal can be difficult to manage. Surgical planning often depends on pre-operative echocardiographic measurements. We aimed to determine the added utility of cardiac MRI in predicting successful biventricular repair in common atrioventricular canal. METHODS: We conducted a retrospective cohort study of children with common atrioventricular canal who underwent MRI prior to repair. Associations between MRI and echocardiographic measures and surgical outcome were tested using logistic regression, and models were compared using area under the receiver operator characteristic curve. RESULTS: We included 28 patients (median age at MRI: 5.2 months). The optimal MRI model included the novel end-diastolic volume index (using the ratio of left ventricular end-diastolic volume to total end-diastolic volume) and the left ventricle-right ventricle angle in diastole (area under the curve 0.83, p = 0.041). End-diastolic volume index ≤ 0.18 and left ventricle-right ventricle angle in diastole ≤ 72° yield a sensitivity of 83% and specificity of 81% for successful biventricular repair. The optimal multimodality model included the end-diastolic volume index and the echocardiographic atrioventricular valve index with an area under the curve of 0.87 (p = 0.026). CONCLUSIONS: Cardiac MRI can successfully predict successful biventricular repair in patients with unbalanced common atrioventricular canal utilising the end-diastolic volume index alone or in combination with the MRI left ventricle-right ventricle angle in diastole or the echocardiographic atrioventricular valve index. A prospective cardiac MRI study is warranted to better define the multimodality characteristic predictive of successful biventricular surgery.

Longitudinal Trends of Vascular Flow and Growth in Patients Undergoing Fontan Operation.

BACKGROUND: Single ventricle (SV) patients undergo multiple surgeries with subsequent changes in anatomy and hemodynamics. There are little cardiac magnetic resonance (CMR) data on serial changes in these patients. This study aimed to assess longitudinal changes of SV anatomy and hemodynamics in a large cohort. METHODS: Anatomy and flow in SV patients with serial CMRs performed between 2008 and 2019 at a single institution were retrospectively reviewed. Mixed-effects linear regression was used to estimate changes over time at 3 to 9 months, 1 to 5 years, and >5 years after Fontan. RESULTS: A total of 119 patients were included (51% with hypoplastic left heart syndrome; 77% underwent extracardiac Fontan). A total of 88 patients had 3 serial CMRs. Indexed right superior vena cava, inferior vena cava, neoaortic valve, and descending aorta area decreased over time (beta = -0.19, -0.44, and -0.23, respectively; P < .01), as did indexed right superior vena cava, neoaorta and native aorta, and descending aorta flow (beta = -0.49, -0.53, and -0.59, respectively; P < .0001). Inferior vena cava flow and its contribution to total caval flow increased (beta = 0.33; P < .0001). Indexed right and left pulmonary artery flow did not change; however, indexed left pulmonary artery area decreased (beta = -0.16; P = .0014) with time. Systemic-to-pulmonary collateral flow remained unchanged before and early after Fontan (beta = -0.54; P = .42) but decreased with time from Fontan (beta = -0.22; P < .0001). CONCLUSIONS: In this cohort of longitudinally followed SV patients, there are significant trends in vascular size and flow over time from Fontan. These findings can be used as a framework to interpret serial CMR data in the SV and noninvasively identify deviations from expected patterns before the development of clinical symptoms.

Imposition of Fontan physiology: Effects on strain and global measures of ventricular function.

OBJECTIVE: We sought to evaluate contractile function in single-ventricle patients before and after imposition of Fontan physiology. METHODS: Single right ventricle (SRV; n = 38) and single left ventricle (SLV; n = 11) patients underwent cardiac magnetic resonance imaging pre and post Fontan operation. Global radial strain (GRS), global circumferential strain (GCS), and global longitudinal strain were measured along with ejection fraction (EF) and atrioventricular valve regurgitation (AVVR). RESULTS: Age at cardiac magnetic resonance imaging before the Fontan operation was 3.1 ± 1.3 years and after the Fontan procedure was 5.8 ± 2.7 years. There were no significant EF differences between SRV and SLV patients before and after the Fontan procedure, and EF did not deteriorate significantly after the Fontan operation. GRS was significantly lower for SRV patients than for SLV patients before (24.3% vs 32.1%; P = .048) and after (21.8% vs 29.7%; P = .045) the Fontan procedure. GRS and GCS of the SRV patients deteriorated significantly after the Fontan operation (GRS, P = .01; GCS, P = .009). Strains showed positive correlations before and after the Fontan operation with positive correlations among each strain. Within all patients, strains correlated positively with EF. Strains and EF negatively correlated with AVVR (GRS P = .03, r = -0.22; GCS P = .03, r = -0.23; EF P < .001, r = -0.37). CONCLUSIONS: Strains were lower for SRV than for SLV patients before and after the Fontan operation and deteriorated after the Fontan operation. Our study suggests that strain measures might detect ventricular deterioration earlier than EF. Because strains before and after the Fontan operation were positively correlated, and negatively correlated with AVVR, the early institution of myocardial protective therapy including AVVR management, especially for SRV patients, might have benefit.

MRI Evaluation of Lymphatic Abnormalities in the Neck and Thorax after Fontan Surgery: Relationship with Outcome.

Background The Fontan operation is performed for surgical palliation of single ventricle physiology. This operation is usually preceded by a superior cavopulmonary connection (SCPC); lymphatic abnormalities after SCPC may be demonstrated at MRI and prior to the Fontan operation. Purpose To determine if the degree of neck and thoracic lymphatic abnormalities at T2-weighted MRI in patients after superior cavopulmonary connection (SCPC) correlated with surgical outcomes from the Fontan procedure. Materials and Methods Patients for whom SCPC was performed for palliation of single ventricle disease who underwent chest MRI between July 2012 and May 2015 at a single institution were retrospectively reviewed. T2-weighted images were scored as lymphatic type 1 (little or no T2 mediastinal and supraclavicular signal) to type 4 (T2 signal into both the mediastinum and the lung parenchyma). Fontan takedown, duration of post-Fontan hospitalization and pleural effusion, postoperative plastic bronchitis, need for transplant, and mortality were tabulated. The relationship between lymphatic type and clinical outcomes was evaluated by using analysis of variance (ANOVA), the Kruskal-Wallis H test, and the Fisher exact test. Results A total of 83 patients (mean age, 7.9 years ± 2.6) were evaluated. Among these 83 patients, 53 (64%) were classified with type 1 or 2 lymphatic abnormalities, 17 (20%) with type 3, and 12 (16%) with type 4. The rate of failure of Fontan completion was higher in patients with type 4 than in type 1 or 2 (54% vs 2%, respectively; P = .004). Need for cardiac transplant (one of 13 [8%]) and death (three of 13 [23%]) occurred only in type 4. Median postoperative length of stay was longer for patients with type 4 than for those with types 1 or 2 (29 days vs 9 days, respectively; P < .01). Conclusion Greater MRI-based severity of lymphatic abnormalities in patients prior to planned Fontan procedure was associated with failure of Fontan completion and longer postoperative stay. © RSNA, 2019 Online supplemental material is available for this article.

Relationship of Aortic Stiffness to Exercise and Ventricular Volumes in Single Ventricles.

BACKGROUND: Patients with single ventricle (SV) may often undergo aortic reconstruction that creates a stiff large vessel, increasing afterload and affecting exercise performance. The objective of this study was to determine the relationship of pulse wave velocity (PWV) and distensibility in reconstructed and normal aortic arches after Fontan with exercise variables. METHODS: PWV and distensibility of the descending aorta at the level of the diaphragm (DAo) were calculated with real-time exercise cardiac magnetic resonance in 48 patients with SV after Fontan (18 after aortic reconstruction; 30 without aortic reconstruction) and compared with metabolic exercise stress test variables. RESULTS: PWV was greater in the reconstructed group than in the non-reconstructed group (median 4.4 m/s [range: 2.3 to 9.8 m/s] versus 3.6 [range: 2.6 to 6.3 m/s], respectively, p = 0.003). Statistically significant inverse correlations were found between PWV and end-diastolic, end-systolic, and stroke volumes at rest and at exercise in the reconstructed group. In addition, inverse correlations also existed in the reconstructed group between distensibility of the DAo and the exercise variables such as peak oxygen pulse (R = 0.56, p = 0.02), peak oxygen consumption (R = 0.63, p = 0.008), oxygen consumption at ventilatory anaerobic threshold (R = 0.48, p = 0.04), and peak work (R = 0.54, p = 0.02). Similar correlations were not seen in patients with non-reconstructed aortas. CONCLUSIONS: Patients with SV with reconstructed aortas have increased aortic stiffness, increasing afterload on the ventricle. Native DAo stiffness distal to the reconstruction is inversely correlated with exercise performance, presumably to decrease impedance mismatch to maintain homogeneity of the aortic wall. This information suggests a possible mechanism for decreased exercise performance in patients with SV with aortic reconstructions.

Longitudinal changes in adolescents with TOF: implications for care.

BACKGROUND: We sought to identify predictors of change in right ventricular function and exercise capacity in adolescents following repair for tetralogy of Fallot. METHODS AND RESULTS: We performed a longitudinal study with serial cardiac magnetic resonance imaging and/or exercise stress tests. Patients with interim intervention on the pulmonary valve were excluded. Paired t-test was used to detect longitudinal changes and multivariable regression models were built to identify predictors of change. Initial and follow up magnetic resonance and exercise stress test studies were available for 65 and 63 subjects, respectively. Age at initial testing was 11.7 ± 2.7 years. Average follow up time was 4.5 ± 1.8 (magnetic resonance) and 4.0 ± 1.6 (exercise test) years. There was a significant increase in right ventricular end diastolic and systolic volume (119 ± 34 to 128 ± 35 ml/m2, P = 0.006; 49 ± 20 to 56 ± 23 ml/m2, P = 0.001, respectively), and a decrease in right ventricular ejection fraction (60 ± 7 to 56 ± 8%, P = 0.001), with no significant change in pulmonary regurgitant fraction or right ventricular cardiac index. Predictors of right ventricular dilation over time included: time elapsed from surgical repair, severity of pulmonary insufficiency and right ventricular dilation at the initial magnetic resonance imaging. Of those, time elapsed from surgical repair had the most significant effect. There was no change in exercise capacity. DISCUSSION: In the adolescent with tetralogy of Fallot, longer time from surgery, more pulmonary insufficiency and greater right ventricular dilation at initial magnetic resonance imaging are associated with progressive right ventricular dilation. These results suggest early monitoring with magnetic resonance imaging might identify those at highest risk for progressive disease.

Capadenoson, a clinically trialed partial adenosine A1 receptor agonist, can stimulate adenosine A2B receptor biased agonism.

The adenosine A2B receptor (A2BAR) has been identified as an important therapeutic target in cardiovascular disease, however in vitro and in vivo targeting has been limited by the paucity of pharmacological tools, particularly potent agonists. Interestingly, 2-((6-amino-3,5-dicyano-4-(4-(cyclopropylmethoxy)phenyl)-2-pyridinyl)thio)acetamide (BAY60-6583), a potent and subtype-selective A2BAR agonist, has the same core structure as 2-amino-6-[[2-(4-chlorophenyl)-1,3-thiazol-4-yl]methylsulfanyl]-4-[4-(2-hydroxyethoxy)phenyl]pyridine-3,5-dicarbonitril (capadenoson). Capadenoson, currently classified as an adenosine A1 receptor (A1AR) partial agonist, has undergone two Phase IIa clinical trials, initially in patients with atrial fibrillation and subsequently in patients with stable angina. Capadenoson has also been shown to decrease cardiac remodeling in an animal model of advanced heart failure and a capadenoson derivative, neladenoson bialanate, recently entered clinical development for the treatment of chronic heart failure. The therapeutic effects of capadenoson are currently thought to be mediated through the A1AR. However, the ability of capadenoson to stimulate additional adenosine receptor subtypes, in particular the A2BAR, has not been rigorously assessed. In this study, we demonstrate that capadenoson does indeed have significant A2BAR activity in physiologically relevant cells, cardiac fibroblasts and cardiomyocytes, which endogenously express the A2BAR. Relative to the non-selective adenosine receptor agonist NECA, capadenoson was a biased A2BAR agonist with a preference for cAMP signal transduction over other downstream mediators in cells with recombinant and endogenous A2BAR expression. These findings suggest the reclassification of capadenoson as a dual A1AR/A2BAR agonist. Furthermore, a potential A2BAR contribution should be an important consideration for the future clinical development of capadenoson-like therapeutics, as the A2BAR can promote cardioprotection and modulate cardiac fibrosis in heart disease.

Rings, slings, and other tracheal disorders in the neonate.

Tracheal and bronchial pathologies in the neonate can be rapidly fatal if prenatal or quick postnatal diagnosis and intervention is not performed. Close multidisciplinary collaboration between multiple medical and surgical specialties is vital to the effective diagnosis and treatment of these pathologies. The fetal and neonatal airway may be affected or compromised by more prevalent pathologies such as tracheomalacia and tracheo-esophageal fistula with esophageal atresia. However, it is imperative that we also consider other potential sources that may perhaps be less familiar such as congenital cardiovascular abnormalities, tracheal stenosis, complete tracheal rings, tracheal sleeve, and foregut duplication cysts. Modern imaging studies and surgical techniques are allowing us to better serve these children.

Cardiac magnetic resonance imaging characterizes stenosis, perfusion, and fibrosis preoperatively and postoperatively in children with anomalous coronary arteries.

OBJECTIVES: Using cardiac magnetic resonance imaging (MRI) with virtual angioscopy, we sought to evaluate coronary anatomy, myocardial injury, and left ventricular function in children with interarterial anomalous aortic origin of coronary artery before and after surgery. METHODS: We prospectively enrolled children 5 to 19 years old with interarterial anomalous coronary artery. Cardiac MRI was performed with respiratory-navigated steady-state free-precession 3-dimensional data set acquisition. Virtual angioscopy was used to evaluate the coronary ostia directly. Surgery consisted of the modified unroofing procedure. RESULTS: We enrolled 9 subjects between February 2009 and May 2015. Subjects were male, with an average age at surgery of 14.1 years. Anomalous coronary was right in 7 patients (77%) and left in 2. In all subjects, the proximal anomalous coronary arose tangential to the aorta with an elliptical, slitlike ostium. Before the operation, the proximal coronary artery was significantly smaller proximally than distally (2 vs 3.1 mm; P < .0001. After the operation, neo-orifices were round and patent in 7 subjects; however, 2 subjects still had narrowed neo-orifices. New postoperative MRI findings included flattened septal wall motion (N = 1), small region of midmyocardial partial-thickness scar (N = 1), and dyskinetic septal wall motion with mild aortic insufficiency (N = 1). Left ventricular function was normal both before and after surgery (P = .85). CONCLUSIONS: Cardiac MRI with virtual angioscopy is an important tool for evaluating anomalous coronary anatomy, myocardial function, and ischemia and should be considered for initial and postoperative assessment of children with anomalous coronary arteries.

High-Resolution, Contrast-Enhanced Cardiac Magnetic Resonance Detects an Intracardiac Thrombus in a Fontan Patient.

A 28-year-old male with Fontan physiology presented with chest pain, elevated troponin, regional dyskinesis, and an apical echogenicity in the right-sided morphologically left ventricle (LV) on echocardiogram. Cardiac magnetic resonance (CMR) imaging was performed with a three-dimensional respiratory-navigated inversion recovery FLASH (low flip angle, spoiled gradient echo technique) sequence during slow gadolinium infusion. A hypointense lesion in the LV apex was consistent with thrombus. Gadolinium-delayed enhancement imaging demonstrated increased signal in the mid-inferior LV free wall. In this case, progressive decline in ventricular function was likely followed by an intracardiac thrombus and embolic myocardial infarction. The CMR was instrumental in characterizing the mass and identifying myocardial scar.

Cardiac Magnetic Resonance Characterizes Myocarditis in a 16-Year-Old Female With Lyme Disease.

Myocarditis may occur during early disseminated Lyme disease. A 16-year-old girl with serologic evidence of Borrelia burgdorferi infection and transient first-degree atrioventricular block underwent cardiac magnetic resonance imaging, which demonstrated myocardial hyperemia, edema, and delayed gadolinium enhancement. We discuss the use of T1- and T2-weighted dark blood sequences in addition to inversion recovery delayed enhancement imaging to support the diagnosis of Lyme myocarditis.

Repaired tetralogy of Fallot with coexisting unrepaired partial anomalous pulmonary venous connection is associated with diminished right ventricular ejection fraction and more severe right ventricular dilation.

BACKGROUND: There is an established association between tetralogy of Fallot and partial anomalous pulmonary venous connections. This association is important because surgically repaired tetralogy patients have increased risk of right heart failure. We hypothesize that partial anomalous venous connections increase right ventricular volumes and worsen right ventricular failure. MATERIALS AND METHODS: We reviewed cardiac MRI exams performed at a tertiary pediatric hospital from January 2005 to January 2014. We identified patients with repaired tetralogy and unrepaired partial anomalous pulmonary venous connection. We used age- and gender-matched repaired tetralogy patients without partial anomalous pulmonary venous connection as controls. We analyzed the MRI results and surgical course and performed comparative statistics to identify group differences. RESULTS: There were eight patients with repaired tetralogy and unrepaired partial anomalous pulmonary venous connection and 16 controls. In all cases, the partial anomalous pulmonary venous connection was not detected on preoperative echocardiography. There were no significant differences in surgical course and body surface area between the two groups. Repaired tetralogy patients with unrepaired partial anomalous pulmonary venous connection showed significantly higher indexed right ventricular end diastolic volume (149 ± 33 mL/m(2) vs. 118 ± 30 mL/m(2)), right ventricle to left ventricle size ratios (3.1 ± 1.3 vs. 1.9 ± 0.5) and a higher incidence of reduced right ventricular ejection fraction compared to controls (3/8 vs. 0/16). CONCLUSION: Repaired tetralogy of Fallot with unrepaired partial anomalous pulmonary venous connection is associated with reduced right ventricular ejection fraction and more significant right ventricular dilation.

Identifying Abnormal Ostial Morphology in Anomalous Aortic Origin of a Coronary Artery.

BACKGROUND: Anomalous origin of a coronary artery from the contralateral sinus of Valsalva is associated with exercise-induced ischemia and sudden death. That is thought to be due to aortic enlargement in patients with an elliptical ostium. We hypothesize that virtual angioscopy can identify abnormal coronary ostial morphology in these patients. METHODS: We retrospectively analyzed 55 consecutive pediatric coronary artery magnetic resonance imaging studies from January 2006 to January 2010 with the diagnosis of anomalous right (n = 20), or left (n = 7) coronary artery, or normal coronary origins (n = 28). One postmortem heart specimen with anomalous left coronary artery was imaged and analyzed to validate our technique. Virtual angioscopy analysis was used for visualization and measurement of the coronary ostia. RESULTS: Distinct aortic origins of the right and left coronaries were seen in all 55 studies. An elliptical orifice with a longer superior-inferior dimension was seen in all anomalous ostia, in contrast to a circular ostium in all normal origins. That was quantified in anomalous ostia with a long-axis to short-axis ratio of 2.5 ± 0.5 (right) and 2.4 ± 0.5 (left) compared with 1.1 ± 0.2 (right) and 1.0 ± 0.3 (left) in controls (p < 0.001 for right and left ostia comparisons). Ostial morphology was confirmed in all 9 patients who underwent operative repair and in 1 patient at autopsy. CONCLUSIONS: Virtual angioscopy identifies abnormal ostial morphology in anomalous coronary artery patients, which is important for characterizing the diagnosis of patients who may be at risk for sudden death.

Doppler-derived flow pattern in the descending aorta does not predict systemic to pulmonary arterial collateral flow in patients with single ventricle palliation: a cross-sectional study.

BACKGROUND: Children with single ventricle heart disease are at risk for developing systemic to pulmonary arterial collateral vessels that adversely impact short-term outcomes, although the effect on long-term outcomes remains unclear. Collateral flow (CollF) can be quantified using cardiac magnetic resonance (CMR) flow quantification. The velocity-time integral (VTI), obtained from spectral Doppler tracings, has been used in "runoff" lesions like aortic regurgitation to quantify insufficiency. We hypothesized that the VTI ratio of the proximal descending aorta (DAo) after cavopulmonary anastomosis (CPA) would estimate CollF. METHODS: A retrospective cross-sectional study was conducted. Patients who had a superior CPA or total CPA and underwent CMR between April 2008 and December 2012 were included. Those with greater than trivial semilunar valve insufficiency or aortic arch obstruction were excluded. In a subset (n = 88), spectral Doppler tracings of the DAo were analyzed to determine the VTI ratio. In another subset (n = 112), CMR was used to determine the ratio of retrograde to antegrade flow in the DAo. RESULTS: There was no linear correlation between VTI ratio and CollF (r (2) = .006, P = .46). There was a weakly positive correlation with CollF (r (2) = .07, P = .007) and the CMR measured ratio of retrograde to antegrade flow. Holodiastolic flow reversal by echo did not predict higher CollF (P = .40), but those with holodiastolic flow reversal by CMR had significantly higher CollF (P = .04). CONCLUSIONS: The ratio of reverse to forward flow in the DAo as determined by Doppler echo does not accurately reflect CollF in children with single ventricle after CPA.

Cardiac MRI and CT: differentiation of normal ostium and intraseptal course from slitlike ostium and interarterial course in anomalous left coronary artery in children.

OBJECTIVE: Anomalous left coronary artery from the inappropriate aortic sinus with intraseptal course is generally benign but can be confused on imaging studies with the potentially lethal interarterial, intramural anomalous left coronary artery. The purpose of this study was to assess normal ostial morphologic features and intraseptal course using cardiac MRI and CT in pediatric patients with intraseptal anomalous left coronary artery. MATERIALS AND METHODS: A retrospective review was conducted of the medical records of 14 children with the diagnosis of intraseptal anomalous left coronary artery between November 2009 and March 2013. Coronary artery origin and course were evaluated with cardiac MRI or CT, and 3D assessment of coronary ostial morphologic features was performed with virtual angioscopy. RESULTS: The patient ages ranged from 5 to 18 years at diagnosis; 10 (71.4%) were boys. The right and left coronary origins were the right sinus of Valsalva as a common origin (n = 9) or a single coronary artery (n = 5). Anomalous intraseptal left main coronary was found in 13 patients, and one patient had anomalous left anterior descending with retroaortic circumflex coronary artery. Anomalous coronary ostia were round and without stenosis in all studies. The anomalous vessel was identified with echocardiography, but the anomalous left coronary artery was not delineated, and a normal ostium was not adequately portrayed in any instance. CONCLUSION: By use of cardiac MRI and CT, the anomalous course of round coronary ostia was confirmed and visualized in a pediatric cohort with intraseptal anomalous left coronary artery. The data provide the basis for understanding the benign clinical course and showing that surgery is unnecessary for this coronary anomaly.

Transient left ventricular wall thickening in a 14-year-old girl with influenza A myocarditis.

We describe a case of influenza A myocarditis and transient left ventricular wall thickening in a 14-year-old girl presenting with acute heart failure. Admission echocardiogram revealed significant left ventricular hypertrophy with depressed left ventricular systolic function. The aetiology of the ventricular thickening was demonstrated to be myocardial oedema using cardiac magnetic resonance imaging. The natural course of this unusual clinical presentation of acute myocarditis and the importance of cardiac magnetic resonance imaging in this challenging clinical setting are discussed.

Right coronary artery from right sinus of Valsalva and ventricular tachycardia.

Congenital coronary anomalies in which the coronary artery arises from the contralateral aortic sinus of Valsalva are associated with fatal arrhythmias and sudden death. The mechanism causing sudden death has been debated. We describe a case of an adolescent patient with right coronary artery arising leftward, but from the right sinus of Valsalva, with an acute-angle takeoff from the aorta and an intramural course, who presents with exercise-induced ventricular tachycardia.

Brain magnetic resonance immediately before surgery in single ventricles and surgical postponement.

BACKGROUND: Single-ventricle patients undergoing surgical reconstruction experience a high rate of brain injury. Incidental findings on preoperative brain scans may result in safety considerations involving hemorrhage extension during cardiopulmonary bypass that result in surgical postponement. METHODS: Single-ventricle patients were studied with brain scans immediately preoperatively, as part of a National Institutes of Health study, and were reviewed by neuroradiology immediately before cardiopulmonary bypass. RESULTS: Of 144 consecutive patients recruited into the project, 33 were studied before stage I (3.7±1.8 days), 34 before bidirectional Glenn (5.8±0.5 months), and 67 before Fontan (3.3±1.1 years) operations. Six operations (4.5%), 2 before stage I, 3 before bidirectional Glenn, and 1 before Fontan, were postponed because of concerning findings on brain magnetic resonance imaging. Five were due to unexpected incidental findings of acute intracranial hemorrhage, and 1 was due to diffuse cerebellar cytotoxic edema; none who proceeded to operation had these lesions. Prematurity and genetic syndromes were not present in any patients with a postponed operation. Four of 4 before bidirectional Glenn/Fontan with surgical delays had hypoplastic left heart syndrome compared with 44 of 97 who did not (p=0.048). After observation and follow-up, all eventually had successful operations with bypass. CONCLUSIONS: Preoperative brain magnetic resonance imaging performed in children with single ventricles disclosed injuries in 4.5% leading to surgical delay; hemorrhagic lesions were most common and raised concerns for extension during the operation. The true risk of progression and need for delay of the operation due to heparinization associated with these lesions remains uncertain.

MRI of lymphatic abnormalities after functional single-ventricle palliation surgery.

OBJECTIVE: Protein-losing enteropathy (PLE) and plastic bronchitis are serious complications that occur after single-ventricle surgery. A lymphatic cause for these conditions has been proposed, but imaging correlation has not been reported. The objective of this study was to evaluate lymphatic abnormalities in patients after functional single-ventricle palliation compared with patients with non-single-ventricle congenital heart conditions using T2-weighted MR lymphangiography. MATERIALS AND METHODS: We retrospectively reviewed imaging data from 48 patients who underwent T2-weighted MR lymphangiography in our institution between May 1, 2012, and October 24, 2012. The patients were divided into four groups: patients who underwent superior cavopulmonary connection, patients who underwent total cavopulmonary connection, patients with total cavopulmonary connection and lymphatic complications, and patients with non-single-ventricle cardiac anomalies. RESULTS: There were 38 patients with single ventricles in this study. The lymphatic abnormalities observed in these patients included thoracic duct dilation greater than 3 mm (31%), lymphangiectasia and lymphatic collateralization (78%), and tissue edema (86%). There were five patients with PLE, one patient with plastic bronchitis, and one patient with chronic chylous effusions and superior cavopulmonary connection. The patients with PLE and plastic bronchitis had statistically significant larger thoracic duct maximal diameters (median, 3.9 mm; range, 3-7.2 mm) than did the other patients with total cavopulmonary connection (p < 0.01). In the two-ventricle patient group, there were no abnormal lymphatic findings. CONCLUSION: Lymphatic abnormalities are found in many patients after functional single-ventricle palliation. T2-weighted unenhanced MRI is capable of anatomic assessment of the lymphatic system in this patient population and has promise for guiding treatment in the future.

X-ray magnetic resonance fusion modality may reduce radiation exposure and contrast dose in diagnostic cardiac catheterization of congenital heart disease.

BACKGROUND: Radiation exposure in the pediatric population may increase the risk of future malignancy. Children with congenital heart disease who often undergo repeated catheterizations are at risk. One possible strategy to reduce radiation is to use X-ray Magnetic Resonance Fusion (XMRF) to facilitate cardiac catheterization. METHODS: Catheterization data of patients who underwent diagnostic XMRF procedures between January 1, 2009 and February 1, 2012 were reviewed. Cases were matched 1:1 to contemporary controls who did not undergo XMRF based on weight and diagnosis and were compared in radiation exposure, contrast dose, and procedural and anesthesia times. RESULTS: Forty-four matched pairs were included. Baseline demographics were similar in both groups. Patients in the XMRF group had lower indices of radiation exposure measured by fluoroscopy time (14 vs. 16.4 vs. P = 0.047), dose-area product from fluoroscopy (513.2 vs. 589.1 µGy·m(2) , P = 0.042), total dose-area product (625.8 vs. 995.2 µGy·m(2) , P = 0.027), and total air kerma dose (94.5 vs. 153.8 mGy, P = 0.017). There was also a significant reduction in contrast dose (2 vs. 3.3 cc/kg, P <0.001). Procedural time tended to be shorter in the XMRF group but anesthesia time was significantly longer. CONCLUSION: Select diagnostic cardiac catheterization cases that utilized XMRF used less radiation and contrast than similar cases where XMRF was not used. Future work is needed to determine whether similar benefits can be extended to other types of diagnostic and complex interventional procedures.