Behavioral-play familiarization for non-sedated magnetic resonance imaging in young children with mild traumatic brain injury.

BACKGROUND: Mild traumatic brain injury (mTBI) sustained in early childhood affects the brain at a peak developmental period and may disrupt sensitive stages of skill acquisition, thereby compromising child functioning. However, due to the challenges of collecting non-sedated neuroimaging data in young children, the consequences of mTBI on young children's brains have not been systematically studied. In typically developing preschool children (of age 3-5years), a brief behavioral-play familiarization provides an effective alternative to sedation for acquiring awake magnetic resonance imaging (MRI) in a time- and resource-efficient manner. To date, no study has applied such an approach for acquiring non-sedated MRI in preschool children with mTBI who may present with additional MRI acquisition challenges such as agitation or anxiety. OBJECTIVE: The present study aimed to compare the effectiveness of a brief behavioral-play familiarization for acquiring non-sedated MRI for research purposes between young children with and without mTBI, and to identify factors associated with successful MRI acquisition. MATERIALS AND METHODS: Preschool children with mTBI (n=13) and typically developing children (n=24) underwent a 15-minutes behavioral-play MRI familiarization followed by a 35-minutes non-sedated MRI protocol. Success rate was compared between groups, MRI quality was assessed quantitatively, and factors predicting success were documented. RESULTS: Among the 37 participants, 15 typically developing children (63%) and 10 mTBI (77%) reached the MRI acquisition success criteria (i.e., completing the two first sequences). The success rate was not significantly different between groups (p=.48; 95% CI [-0.36 14.08]; Cramer's V=.15). The images acquired were of high-quality in 100% (for both groups) of the structural images, and 60% (for both groups) of the diffusion images. Factors associated with success included older child age (Β=0.73, p=.007, exp(B)=3.11, 95% CI [1.36 7.08]) and fewer parental concerns (Β=-1.56, p=.02, exp(Β)=0.21, 95% CI [0.05 0.82]) about the MRI procedure. CONCLUSION: Using brief behavioral-play familiarization allows acquisition of high-quality non-sedated MRI in young children with mTBI with success rates comparable to those of non-injured peers.

Non-Invasive Vascular Elastography as a One-Step Imaging Technique to Evaluate Early Vascular Changes in Children Compared to B-Mode-Based Intima-Media Thickness Technique : A Validation Study Using Inter- and Intra-Rater Reliability.

Background: Childhood obesity is linked to higher adult mortality and morbidity from atherosclerosis. It is primordial to detect at-risk children earlier-on to prevent disease progression. Carotid intima-media thickness (IMT) is a subclinical radiological marker for early atherosclerosis. B-mode ultrasound is a known technique to assess IMT, but no gold standard technique exists in children. Non-invasive vascular elastography (NIVE) using speckle statistics is an innovative alternative to evaluate IMT and adds by providing translation, strain and shear strain measurements. Validation studies for both techniques lack in children. Purpose: Validate the reproducibility of the 2 techniques in Canadian children. Methods: We conducted a prospective study where anthropometry, blood pressure, IMT and elastography were measured. Six operators obtained 2 measurements for both carotid arteries using both techniques, for a total of 720 measurements. Inter- and intra-class correlation coefficients (ICC) were calculated for each measurement technique and elastography parameters. Results: 30 participants (13.0 ± 1.26 years, 17 girls) were recruited. Twelve were overweight. No significant difference was found in mean IMT between weight groups for either technique (P = .15 and P = .60). We found excellent inter- (ICC = .98 [95% Confidence Interval (CI): .97; .99]) and intra- (ICC = .90-.93) operator reliability for the B-mode technique, and good inter (ICC = .70 [95% CI: .47; .85]) and intra- (ICC = .71-.91) operator reliability for the NIVE-based technique. Poor reliability was found between techniques (ICC = .30 [95% CI: -.31; .65). For elastography parameters, translation was the most reliable (ICC = .94-.95). Conclusion: IMT measurement is reproducible in children but not between techniques. NIVE gives the advantage of evaluating elastography.

Current applications for measuring pediatric intima-media thickness.

Intima-media thickness is a known subclinical radiologic marker of the early manifestations of atherosclerotic disease. It is the thickness of the vessel wall, most often the carotid artery. Intima-media thickness is measured on conventional US manually or automatically. Other measurement techniques include radiofrequency US. Because there is variation in its measurement, especially in children, several recommendations have been set to increase the measurement's validity and comparability among studies. Despite these recommendations, several pitfalls should be avoided, and quality control should be performed to avoid erroneous interpretation. This article summarizes current literature in relation to the clinical applications for intima-media thickness measurement in children with known risk factors such as obesity, liver steatosis, hypercholesterolemia, diabetes, hypertension, systemic inflammatory diseases, cancer survival, kidney and liver transplant, and sickle cell disease or beta thalassemia major. Most potential indications for intima-media thickness measurement remain in the research domain and should be interpreted combined with other markers. The objective of diagnosing an increased intima-media thickness is to start a multidisciplinary treatment approach to prevent disease progression and its sequelae in adulthood.

PHACES Syndrome and Associated Anomalies: Risk Associated With Small and Large Facial Hemangiomas.

OBJECTIVE. PHACES syndrome includes posterior fossa malformations, hemangioma, arterial anomalies, coarctation of the aorta and cardiac defects, eye abnormalities, and sternal defect with or without supraumbilical raphe. Usually, brain imaging is performed when facial hemangiomas are larger than 5 cm. Data on associated anomalies regardless of hemangioma size are sparse. The objective of this study was to determine, first, the prevalence of PHACES-like associated anomalies in a large sample of infants with all sizes of segmental facial or periorbital focal infantile hemangioma and, second, whether the cutaneous localization of the hemangioma correlates with the type of anomalies present. MATERIALS AND METHODS. The records of all patients of a vascular anomalies practice who had a diagnosis of segmental facial or periorbital focal infantile hemangioma and who had clinical photographs and brain MRI available were reviewed. The clinical photographs were reviewed to determine the localization by segment and lateralization. MRI was reviewed by two experienced pediatric radiologists. If present, cardiovascular anomalies, sternal defects, and eye anomalies were recorded. The criteria for definite and possible PHACES were used. RESULTS. The study included 122 children (90 girls, 32 boys; mean age, 16.6 months). Forty-five (36.9%) children had a facial infantile hemangioma larger than 5 cm. Twenty-two patients (18.0%) had PHACES or possible PHACES syndrome. Cerebrovascular structural anomalies were seen in 14 of 22 and brain anomalies in 6 of 22 patients with PHACES syndrome but in none and one of the patients in the group without PHACES (p < .001). Cardiovascular anomalies were seen in six patients and ocular anomalies in eight patients. All but one of them had PHACES syndrome. CONCLUSION. Clinical concern about associated extracutaneous anomalies is warranted for all children with facial segmental or periorbital focal infantile hemangiomas, including those with small hemangiomas. Further studies are needed to correlate cerebrovascular anomalies with the clinical evolution of hemangiomas and their effects on cerebral perfusion.

Intra-abdominal lymphatic malformation management in light of the updated International Society for the Study of Vascular Anomalies classification.

BACKGROUND: The International Society for the Study of Vascular Anomalies (ISSVA) classification distinguishes between common lymphatic malformations and complex lymphatic anomalies. These entities have overlapping features but differing responses to treatment. Surgery has been the mainstream treatment in intra-abdominal lymphatic malformation, with variable reported success in the literature. OBJECTIVE: The aim of this study was to review the outcome of different treatments for intra-abdominal lymphatic malformations in children. MATERIALS AND METHODS: We retrospectively reviewed all intra-abdominal lymphatic malformations from 1999 to 2019 in children treated by the surgical team or followed in the vascular anomalies clinic of our institution. Children were classified into one of three groups: group A, isolated intra-abdominal lymphatic malformation; group B, common lymphatic malformation in continuity with other regions; or group C, intra-abdominal involvement as part of a complex lymphatic anomaly or associated syndrome. RESULTS: Fifty intra-abdominal lymphatic malformations were diagnosed; five of these were excluded. In group A (n=28), the treatment was surgical resection (n=26) or sclerosing treatment (n=1), with one case of spontaneous regression; no recurrence was observed in 25 patients. In group B (n=7), three patients had partial resection and all had recurrence; four had sclerotherapy alone with good response. In group C (n=10), therapeutic options included surgery, sclerosing treatment and pharmacotherapy, with variable outcomes. CONCLUSION: The management of intra-abdominal malformations requires a team approach. Sclerotherapy is successful in treating macrocystic lymphatic malformation. Surgery is successful in treating isolated intra-abdominal common lymphatic malformation, albeit at times at the cost of intestinal resection, which could be avoided by combining surgery with preoperative sclerotherapy. With surgery there is often limited resectability, and therefore recurrence in intra-abdominal lymphatic malformations that are part of complex lymphatic anomalies associated with syndromes, or in common lymphatic malformations in continuity with other regions. Sclerotherapy is an effective modality in these instances along with pharmacotherapy.

Supravalvular and Valvular Pulmonary Stenosis: Predictive Features and Responsiveness to Percutaneous Dilation.

Supravalvular pulmonary stenosis (SVPS) is considered a rare form of pulmonary stenosis (PS) and represents both a diagnostic and therapeutic challenge. There currently exist no reliable echocardiographic criteria to accurately predict the supravalvular form. The aims of the study were to describe the response to treatment of the different PS presentations and to outline the diagnostic capacity of echocardiogram to differentiate the SVPS from valvular PS (VPS). This retrospective study included 106 patients who underwent percutaneous angioplasty between 2006 and 2017. Interventional outcomes of patients with SVPS were compared to those of patients with VPS. Diagnosis of VPS vs. SVPS by echocardiogram was compared to diagnosis obtained by angiogram. Echocardiogram yielded a sensitivity of 56%, a specificity of 82.5%, a positive predictive value of 50%, and a negative predictive value of 85.7%. Patients with SVPS had a significantly smaller pulmonary artery to pulmonary valve (PA:PV) ratio. At 6-12 months of follow-up, the VPS group had a mean right ventricular to pulmonary artery (RV-PA) gradient of 21.68 ± 19.85 mmHg compared to 45.27 ± 24.58 mmHg in the SVPS group. Patients with SVPS had a higher rate of reintervention than patients with VPS (32% vs. 6.2%, p < 0.001). There was no difference in major complications between groups, whereas VPS patients had a higher proportion of pulmonary insufficiency. Percutaneous angioplasty for PS is less effective in patients with a supravalvular component. A better understanding of the underlying histopathology of different PS subtypes could lead to development of different techniques to improve outcomes, with fewer reinterventions, in this population.

How Well Are Radiology Residents Prepared for Practice After Training? A Survey of French-Speaking Quebec Recent Graduates and Department Chiefs.

OBJECTIVE: Radiology residents must fulfill a standardized curriculum to complete residency and pass a certification exam before they are granted a licence to practice. We sought to evaluate how well residency prepares trainees for practice as perceived by recent graduates and their department chiefs. Subjects and Methods: Radiologists who graduated from the 4 Quebec radiology residency programs between 2005 and 2016 (n = 237) and Quebec radiology department chiefs (n = 98) were anonymously surveyed. Two electronic surveys were created, for recent graduates (74 questions) and for department chiefs (11 questions), with multiple-choice questions and open questions covering all fields of radiology. Surveys were administered between April and June 2016 using the Association des radiologistes du Québec database. RESULTS: Response rate was 75 (31.6%) of 237 from recent graduates and 96% rated their training as excellent or good. Satisfaction with training in computed tomography and magnetic resonance imaging was high, with musculoskeletal (MSK) imaging, particularly MSK ultrasound (US), as well as pediatric, cardiac, and vascular imaging needing more training. Thirty-nine (39.8%) of 98 department chiefs answered the survey and highlighted weaknesses in the interpretation of conventional radiography, obstetrical US, and invasive procedures, as well as limited leadership and administrative skills. Recent graduates and department chiefs both reported difficulties in the ability to interpret daily volume of examinations as scheduled and invasive procedure competency. CONCLUSION: This survey highlights areas of the radiology curriculum which may benefit from more emphasis during training. Adjustments in the residency program would ensure graduates are successful both in their certification exams and clinical practice.

Left Superior Vena Cava in the Fetus: A Rarely Isolated Anomaly.

The frequency of chromosomal anomalies among fetuses with isolated persistent left superior vena cava (PLSVC) is still debated. The objective of the present study was to assess the prevalence of genetic and morphological anomalies identified in fetuses with PLSVC. We conducted a single-center retrospective study including all fetuses diagnosed with a PLSVC between 2010 and 2017. PLSVC was categorized as isolated or associated according to antenatal diagnosis of associated congenital heart defects, hypoplastic aortic isthmus, abnormal venous/arterial connections, and extracardiac anomalies. Among 229 fetuses diagnosed with PLSVC, 39 cases (17%) were strictly isolated and no syndromic/genetic anomaly or aortic coarctation was diagnosed. Seventy-two fetuses had a cardiovascular defect with a rate of genetic anomalies of 22%, 29 had an extracardiac malformation, and 89 had both an extracardiac and a cardiovascular defect. Among fetuses with abnormal development of the arterial/venous system as the only associated anomaly such as aberrant right subclavian artery or absent ductus venosus, 22% had a genetic anomaly. Overall, sixty-five fetuses or infants had a genetic concern, including 23 aneuploidies, 15 pathogenic micro-deletions/duplications, and 5 variants of unknown significance; 12 patients had VACTERL association, and 12 heterotaxy syndrome. Seven infants had an aortic coarctation diagnosed at birth.In conclusion, a thorough prenatal ultrasound examination is paramount, and the identification of variants of the venous/arterial system in addition to PLSVC should raise suspicion for genetic or morphologic abnormalities. Invasive prenatal diagnosis with array-CGH should be offered when PLSVC is non-isolated, after a detailed ultrasound evaluation in a tertiary center.

The value of non-invasive vascular elastography (NIVE) in detecting early vascular changes in overweight and obese children.

OBJECTIVES: Evaluate non-invasive vascular elastography (NIVE) in detecting vascular changes associated with obese children. METHODS: Case-control study to evaluate NIVE in 120 children, 60 with elevated body mass index (BMI) (≥ 85th percentile for age and sex). Participants were randomly selected from a longitudinal cohort, evaluating consequences of obesity in healthy children with one obese parent. Radiofrequency ultrasound videos of the common carotid artery were obtained. The carotid wall was segmented and NIVE applied to measure cumulated axial strain (CAS), cumulated axial translation (CAT), cumulated lateral translation (CLT), maximal shear strain (Max |SSE|), and intima-media thickness (IMT). Multivariate analyses were used controlling for age, sex, Tanner stage, blood pressure, and low-density lipoprotein. Statistical significance was set to 0.05-0.008. Participants were 10-13 years old (mean 11.4 and 12.0, for normal and elevated BMI groups, p < 0.001), 58% and 63% boys, respectively. Groups differed in age, Tanner stage, and blood pressure. In the normal BMI group, there was weak correlation between systolic blood pressure and Max |SSE| (r = 0.316, p = 0.01) and weak correlation between pulse pressure and Max |SSE| (r = 0.259, p = 0.045). After Bonferroni correction, CAT was significantly higher in the elevated BMI group (0.68 ± 0.24 mm vs. 0.52 ± 0.18 mm), p < 0.001. CAS/CAT was significantly lower in the elevated BMI group (9.54 ± 4.8 vs. 13.34 ± 6.46), p = 0.001. IMT was significantly higher in the elevated BMI group (0.36 ± 0.05 mm vs. 0.32 ± 0.05 mm) before Bonferroni correction, p = 0.013. CONCLUSIONS: NIVE detected differences in CAT and CAS/CAT in elevated BMI children. NIVE is a promising technique to monitor radiological markers of subclinical atherosclerosis. KEY POINTS: • NIVE is a non-invasive technique based on measurement of subsegmental focal deformation of vascular wall to detect subclinical changes in arterial wall compliance. • Children with elevated BMI showed increased carotid artery wall movement during systole, as compared to normal BMI children (mean 0.68 ± 0.24 mm vs. 0.52 ± 0.18 mm; p < 0.001) and a lower ratio of vascular wall strain to wall movement during systole (mean 9.54 ± 4.8 vs. 13.34 ± 6.46; p = 0.001). • The detection of these subclinical changes helps physicians in the stratification of children at risk of atherosclerosis and guides in the implementation of preventive measures.

Carotid artery intima-media thickness measurement in children with normal and increased body mass index: a comparison of three techniques.

BACKGROUND: Common carotid artery intima-media thickness is a marker of subclinical atherosclerosis. In children, increased intima-media thickness is associated with obesity and the risk of cardiovascular events in adulthood. OBJECTIVE: To compare intima-media thickness measurements using B-mode ultrasound, radiofrequency (RF) echo tracking, and RF speckle probability distribution in children with normal and increased body mass index (BMI). MATERIALS AND METHODS: We prospectively measured intima-media thickness in 120 children randomly selected from two groups of a longitudinal cohort: normal BMI and increased BMI, defined by BMI ≥85th percentile for age and gender. We followed Mannheim recommendations. We used M'Ath-Std for automated B-mode imaging, M-line processing of RF signal amplitude for RF echo tracking, and RF signal segmentation and averaging using probability distributions defining image speckle. Statistical analysis included Wilcoxon and Mann-Whitney tests, and Pearson correlation coefficient and intra-class correlation coefficient (ICC). RESULTS: Children were 10-13 years old (mean: 11.7 years); 61% were boys. The mean age was 11.4 years (range: 10.0-13.1 years) for the normal BMI group and 12.0 years (range: 10.1-13.5 years) for the increased BMI group. The normal BMI group included 58% boys and the increased BMI group 63% boys. RF echo tracking method was successful in 79 children as opposed to 114 for the B-mode method and all 120 for the probability distribution method. Techniques were weakly correlated: ICC=0.34 (95% confidence interval [CI]: 0.27-0.39). Intima-media thickness was significantly higher in the increased BMI than normal BMI group using the RF techniques and borderline for the B-mode technique. Mean differences between weight groups were: B-mode, 0.02 mm (95% CI: 0.00 to 0.04), P=0.05; RF echo tracking, 0.03 mm (95% CI: 0.01 to 0.05), P=0.01; and RF speckle probability distribution, 0.03 mm (95% CI: 0.01 to 0.05), P=0.002. CONCLUSION: Though techniques are not interchangeable, all showed increased intima-media thickness in children with increased BMI. RF echo tracking method had the lowest success rate at calculating intima-media thickness. For patient follow-up and cohort comparisons, the same technique should be used throughout.

Correction to: Carotid artery intima-media thickness measurement in children with normal and increased body mass index: a comparison of three techniques.

The original version of this article contained a mistake in Fig. 1: The old version was used during figure processing instead of the replacement. The correct figure is shown below. The original article has been corrected.

Significance of lung anomalies in fetuses affected by tetralogy of Fallot with absent pulmonary valve syndrome.

OBJECTIVES: Tetralogy of Fallot with absent pulmonary valve syndrome is a rare form of tetralogy of Fallot with dilatation of large pulmonary arteries. Prognosis is related to the severity of the cardiac malformation and to bronchial tree compression by dilated pulmonary arteries. This study analyses the prenatal echographic lung appearance in fetuses with tetralogy of Fallot with absent pulmonary valve and discusses its significance. METHODS: We carried out a retrospective review of fetal and postnatal files of nine fetuses diagnosed with tetralogy of Fallot with absent pulmonary valve syndrome in our institution. Correlations of prenatal ultrasound and cardiac imaging findings were obtained with outcome. RESULTS: Abnormal heterogeneous fetal lung echogenicity was detected in eight cases out of nine, always associated with significant lobar arterial dilatation. This aspect was well correlated with postnatal imaging and outcome in the four neonatal cases. The only fetus with normal lung echogenicity also had lower degree of pulmonary artery dilatation in the series. CONCLUSIONS: This study demonstrates that a heterogeneous ultrasound appearance of the fetal lungs can be detected in utero in the most severe cases. This aspect suggests an already significant compression of the fetal bronchial tree by the dilated arteries that may have prognostic implications.

Importance of anatomical dominance in the evaluation of coronary dilatation in Kawasaki disease.

Introduction In Kawasaki disease, although coronary dilatation is attributed to vasculitis, the effect of myocardial inflammation is underestimated. Coronary dilatations are determined by Z-scores, which do not take into account dominance. The aim of the present study was to describe the impact of coronary dominance on dilatation in Kawasaki disease. METHODS: We performed a retrospective analysis of coronary dilatations according to angiography categorisation of dominance. RESULTS: Of 28 patients (2.6 [0.2-10.1] years), right dominance was present in 15 patients and left in 13. Early dilatation was present in all patients, of whom 11 were ipsilateral to the dominant segment and 17 contralateral. Ipsilateral dilatations were present at diagnosis (9/11 versus 6/17, p=0.02) compared with contralateral dilatations, which developed 2 weeks after diagnosis (9/11 versus 16/17, p=0.29). Coronary artery Z-scores of patients with contralateral dilatation increased at 2 weeks, before returning to baseline values (2.0±2.2 at diagnosis, 4.1±1.8 at 2 weeks, 1.8±1.2 at 3-6 months, p=0.001), compared with patients with ipsilateral dilatation in whom Z-scores were maximal at diagnosis and remained stable (3.0±0.9, 2.7±1.1 and 2.6±1.5, respectively, p=0.13). Dominant coronary artery Z-scores were higher compared with non-dominant segments at diagnosis (3.0±0.9 versus 1.0±0.8, p<0.001) and at late follow-up (2.6±1.5 versus 0.4±1.4, p=0.002) in patients with ipsilateral dilatation. CONCLUSION: Progression of coronary dilatation after diagnosis may be a sign of dilatation secondary to vasculitis, as opposed to regression of Z-scores in ipsilateral dilatations, probably related to physiological vasodilatation in response to carditis. This needs to be validated in larger studies against vasculitic and myocardial inflammatory markers.

Large Amplatzer atrial septal occluder in growing children: an echographic study.

BACKGROUND: Lesions of adjacent structures have been reported after closure of large atrial septal defects with the Amplatzer septal occluder. In children, growth of the heart should modify the initial relationship between the device and surrounding structures. AIM: To compare the relationship between large Amplatzer septal occluder and adjacent cardiac structures at short-, mid-, and long-term follow-up in at-risk paediatric population using echocardiography. METHODS: A total of 25 children (4.6±2.9 years old, 18 girls) with the largest atrial septal defect devices implanted between 1997 and 2002 were enrolled prospectively for complete echocardiogram 17.8±10.5 months (mid-term follow-up) and 8.8±0.9 years (long-term follow-up) after the procedure. RESULTS were compared with the echocardiogram carried out 2.1±3.4 days after the procedure (short-term follow-up). RESULTS: The minimal distance between the left disk and the mitral valve increased: 1.4±2.0 mm at short-term and 5.1±2.3 mm at long-term follow-up (p<0.05), leading to less contact between the disk and the anterior leaflet and less mitral regurgitation (10 at short-term, 4 at long-term follow-up, p<0.05). The number of devices straddling the aorta decreased from 17 to 12 at long-term follow-up (p<0.05). There was protrusion of disk in the venous structure in seven patients on the first echocardiogram, which disappeared at long-term follow-up. CONCLUSION: Although frequently in close contact with the aortic root, mitral valve, or venous returns, large devices tend to centre and move away from the surrounding structures, with decreased risk for long-term distortion.

Percutaneous angioplasty used to manage native and recurrent coarctation of the aorta in infants younger than 1 year: immediate and midterm results.

Balloon angioplasty (BAP) used to manage native coarctation of the aorta (CoAo) in infants remains controversial. This study aimed to compare short- and midterm results of BAP between native CoAo (NaCo) and postsurgical recoarctations (ReCo) in infants younger than 1 year. This retrospective study compared the clinical, echocardiographic, hemodynamic, and angiographic data for infants who underwent BAP between July 2003 and September 2012. The 12 NaCo and 13 ReCo patients in this study underwent BAP at 4.61 ± 3.69 and 4.88 ± 3.07 months (p = 0.84) and weighed 5.49 ± 2.57 and 6.10 ± 2.11 kg (p = 0.52), respectively. Their respective heights were 60.58 ± 10.58 and 61.15 ± 6.74 cm (p = 0.87). All the ReCo patients had their initial surgery before the age of 3 months. The minimal CoAo diameter was 2.81 ± 0.96 mm in the NaCo group and 2.86 ± 1.0 mm in the ReCo group (p = 0.90). The relative gradient reduction was 62.79 ± 32.43 % in the NaCo group and 73.37 ± 20.78 % in the ReCo group (p = 0.33). The in situ complication rate (pseudoaneurysm) was 8.33 % in the NaCo group and 7.69 % in the ReCo group (p = 0.74). During the early follow-up evaluation, five NaCo patients (41.66 %) presented with recoarctation requiring BAP reintervention within 1.75 ± 1.41 months (all had their initial BAP before 3 months of age) compared with 1 ReCo patient (7.69 %) (p = 0.165). The mean follow-up period was 3.09 ± 2.69 years for the NaCo patients and 3.6 ± 3.18 years for the ReCo patients (p = 0.69), during which the blood pressure gradient was 12.33 ± 9.67 for the NaCo patients and 7.80 ± 8.78 for the ReCo patients (p = 0.17), with corresponding Doppler peak instantaneous gradients of 21.29 ± 11.19 and 16.20 ± 10.23 (p = 0.24). The resultant diameter ratio between the minimal isthmus diameter and the aortic diameter at the diaphragmatic level was 0.81 ± 0.15 in the NaCo group and 0.85 ± 0.12 in the ReCo group (p = 0.53). The immediate and midterm results of BAP for the NaCo and ReCo infants were comparable. Accordingly, BAP seems to be an acceptable alternative to surgery for infants older than 3 months.

Long-term follow-up of large atrial septal occluder (Amplatzer device) with cardiac MRI in a pediatric population.

OBJECTIVE: The purpose of this study is to evaluate the position and the progress of large Amplatzer septal occluder (ASO) devices relevant to adjacent cardiac structures in growing children using MRI. MATERIALS AND METHODS: Institutional review board approval for this study was obtained. Twenty-five children who underwent large ASO implantation were evaluated using MRI. All subjects were initially imaged 7 years earlier using the same protocol. Spatial and dynamic relationships between the ASO and the adjacent cardiac structures were compared to assess the progress over the 7-year growth span with respect to protrusion, contact, and extrinsic deformity of the mitral valve, the left atrial roof, the aortic annulus and root, and the ostia of adjacent veins. RESULTS: No long-term device-related complications were documented during follow-up. Impingement of the ASO into the opening of the right superior and inferior pulmonary veins and the superior and inferior vena cava resolved completely, compared with initial observations, in five of 16, three of three, five of 10, and three of nine patients, respectively, and significantly regressed in the remaining patients. The device's contact with the mitral valve and the left atrial roof and the aortic root deformity resolved in seven of 10, 11 of 20, and 10 of 18 cases, respectively. CONCLUSION: The distance between the ASO and the surrounding structures increases with time in growing children who require large ASO devices, likely decreasing the risk of long-term complications.

Right pulmonary artery torsion following surgical reimplantation.

We report the case of a 3-month-old boy with an anomalous origin of right pulmonary artery (AORPA) from the ascending aorta who presented postoperatively with torsion of the right pulmonary artery demonstrated on 3-D volume-rendered CT angiogram. To our knowledge, CT images of this entity have not been reported. This case illustrates a rare surgical complication that can be easily imaged by CT.

Right ventricle myocardial perfusion scintigraphy: feasibility and expected values in children.

Stress myocardial perfusion scintigraphy imaging (SMPSI) has important applications for evaluating coronary disease and ventricular function. Studies consistently focus on the left ventricle (LV), with no normal right ventricle (RV) data available. This study sought to evaluate the feasibility of RV perfusion with technetium (Tc-99m) sestamibi using a low radiotracer dose for children free of coronary artery (CA) anomalies and to determine its normal pattern. Patients with a history of Kawasaki disease who showed no coronary complications on selective angiography or no LV perfusion defects on SMPSI were studied at rest and during an exercise challenge. The RV uptake counts were compared with those for different segments of the LV, and multiple ratios of the uptakes between RV and LV segments were calculated. The study subjects were 23 children (age, 11.1 ± 3.3 years) imaged with 0.12 ± 0.03 mCi/kg at rest and 0.31 ± 0.06 mCi/kg during stress. The RV to LV uptake proportion was approximately 6%. Exercise-related uptake increased threefold in both the RV and the LV. The findings showed RV myocardial scintigraphy to be feasible with reproducible ratios. Potential clinical applications include acquired and congenital CA anomalies such as Kawasaki disease, right CA ostium stenosis after a switch operation, and anomalous origin of the right CA.

Characterization of blood-mimicking fluids for echocardiography imaging of ventricular septal defects.

PURPOSE: Ventricular septal defects (VSD) are congenital heart malformations and, in severe cases, they require complex interventions under echocardiography guidance. Heart phantoms can be helpful to train and to understand the complex hemodynamics of VSD. The goal of this study was to characterize the best blood mimicking fluids in such heart phantoms for modelling the hemodynamics of VSD patients using echocardiography. METHODS: Four fluid compositions were considered. Distilled water was used as a baseline, while the other three fluids were developed based on physical properties of human blood, such as the viscosity and the refractive index. Three bi-ventricular heart phantoms of three different pediatric patients with complex VSD were designed from preoperative CT imaging. Custom molds were printed in 3-D and the anatomical structure was casted in polyvinyl alcohol cryogel. The VSD in each heart phantom were observed using echocardiography and color Doppler imaging was used for the hemodynamic study. RESULTS: Heart phantoms with blood mimicking fluids of 30% glycerol and 27% glycerol, 10% sodium iodide were found to be anatomically realistic under echocardiography imaging. Hemodynamic parameters such as the pressure gradient and the volume of the shunt were characterized using color Doppler imaging. CONCLUSION: Proper composition of blood mimicking fluids are important for improving the realism in echocardiographic heart phantoms and they contribute to better understand the complex hemodynamic of VSD under echocardiography.

Navigation guidance for ventricular septal defect closure in heart phantoms.

PURPOSE: Transesophageal echocardiography (TEE) is the preferred imaging modality in a hybrid procedure used to close ventricular septal defects (VSDs). However, the limited field of view of TEE hinders the maneuvering of surgical instruments inside the beating heart. This study evaluates the accuracy of a method that aims to support navigation guidance in the hybrid procedure. METHODS: A cardiologist maneuvered a needle to puncture the patient's heart and to access a VSD, guided by information displayed in a virtual environment. The information displayed included a model of the patient's heart and a virtual needle that reproduced the position and orientation of the real needle in real time. The physical and the virtual worlds were calibrated with a landmark registration and an iterative closest point algorithms, using an electromagnetic measurement system (EMS). For experiments, we developed a setup that included heart phantoms representing the patient's heart. RESULTS: Experimental results from two pediatric cases studied suggested that the information provided for guidance was accurate enough when the landmark registration algorithm was fed with coordinates of seven points clearly identified on the surfaces of the physical and virtual hearts. Indeed, with a registration error of 2.28 mm RMS, it was possible to successfully access two VSDs (6.2 mm and 6.3 mm in diameter) in all the attempts with a needle (5 attempts) and a guidewire (7 attempts). CONCLUSION: We found that information provided in a virtual environment facilitates guidance in the hybrid procedure for VSD closure. A clear identification of anatomical details in the heart surfaces is key to the accuracy of the procedure.