Laureen Sena

Range of ventricular dimensions and function by steady‐state free precession cine MRI in repaired tetralogy of Fallot: Right ventricular outflow tract patch vs. conduit repair

To characterize the range of biventricular size and function evaluated by steady‐state free precession (SSFP) cine magnetic resonance (MR) in a large cohort of patients with repaired tetralogy of Fallot (TOF), and to compare these measurements in those with a right ventricular outflow tract (RVOT) patch vs. a right ventricle‐to‐pulmonary artery (RV‐PA) conduit.

Health supervision in the management of children and adolescents with IBD: NASPGHAN recommendations

Ulcerative colitis (UC) and Crohn disease (CD), collectively referred to as inflammatory bowel disease (IBD), are chronic inflammatory disorders that can affect the gastrointestinal tract of children and adults. Like other autoimmune processes, the cause(s) of these disorders remain unknown but likely involves some interplay between genetic vulnerability and environmental factors. Children, in particular with UC or CD, can present to their primary care providers with similar symptoms, including abdominal pain, diarrhea, weight loss, and bloody stool. Although UC and CD are more predominant in adults, epidemiologic studies have demonstrated that a significant percentage of these patients were diagnosed during childhood. The chronic nature of the inflammatory process observed in these children and the waxing and waning nature of their clinical symptoms can be especially disruptive to their physical, social, and academic development. As such, physicians caring for children must consider these diseases when evaluating patients with compatible symptoms. Recent research efforts have made available a variety of more specific and effective pharmacologic agents and improved endoscopic and radiologic assessment tools to assist clinicians in the diagnosis and interval assessment of their patients with IBD; however, as the level of complexity of these interventions has increased, so too has the need for practitioners to become familiar with a wider array of treatments and the risks and benefits of particular diagnostic testing. Nonetheless, in most cases, and especially when frequent visits to subspecialty referral centers are not geographically feasible, primary care providers can be active participants in the management of their pediatric patients with IBD. The goal of this article is to educate and assist pediatricians and adult gastroenterology physicians caring for children with IBD, and in doing so, help to develop more collaborative care plans between primary care and subspecialty providers.

MDCT evaluation of pulmonary embolism in children and young adults following a lateral tunnel Fontan procedure: optimizing contrast-enhancement techniques

BackgroundPulmonary embolism (PE) is a life-threatening thromboembolic complication in patients who have undergone a Fontan procedure for augmenting pulmonary blood flow in the setting of single-ventricle physiology. In patients following a Fontan procedure, lack of proper contrast agent mixing in the right atrium and sluggish, low-velocity blood flow within the Fontan circulation often results in suboptimal contrast enhancement within the pulmonary artery for evaluating PE. Unfortunately, there is a paucity of information describing the optimal contrast-enhancement technique with multidetector CT (MDCT) for evaluating PE in children and young adults following a Fontan procedure.ObjectiveWe illustrate the MDCT imaging findings of suboptimal contrast enhancement within the pulmonary artery, which can be mistaken for PE, in patients following a lateral Fontan procedure, and we discuss MDCT techniques to optimize contrast enhancement within the pulmonary artery in these patients for evaluating PE.Materials and methodsThe MDCT imaging findings in pediatric and young adult patients following a lateral Fontan procedure and with clinically suspected PE are illustrated. We describe intravenous contrast agent injection techniques that can be used to optimize the contrast enhancement in the pulmonary artery in patients following a lateral Fontan procedure.ResultsThe use of a suboptimal contrast-enhancement technique led to initial misdiagnosis and incomplete evaluation of PE in the three patients following a lateral Fontan procedure. Imaging in two patients showed that optimal evaluation of thrombosis in the Fontan pathway and PE in the pulmonary arteries can be successfully achieved with simultaneous upper- and lower-limb injections of contrast agent.ConclusionThis series demonstrates that suboptimal contrast enhancement can result in misdiagnosis or incomplete evaluation of PE in children and young adults following a lateral Fontan procedure. Careful attention to optimizing contrast enhancement during MDCT examination for evaluation of PE in these patients is essential to prevent misdiagnosis and incomplete evaluation.

Magnetic resonance lymphangiography with a nano-sized gadolinium-labeled dendrimer in small and large animal models

AIM Imaging of the lymphatic system is critical in preoperative planning of resections of complex lymphatic malformations. However, safe, effective imaging methods with sufficient resolution to identify the lymphatics have been lacking. In this study, we demonstrate the use of gadolinium-labeled dendrimers to image the lymphatics in small and large animal models during magnetic resonance lymphangiography. METHODS Polyamidoamine G6-Gd_1B4M_N-hydroxysuccinimide was synthesized and administered intradermally in the extremities of normal mice and pigs at several doses. RESULTS The lymphatics were well demonstrated in both animal models and there was rapid uptake in the deep lymphatic system, including the thoracic duct. A significant dose reduction was achieved (1 µmol Gd/kg) in the 35-kg pig compared with mice, while still producing excellent results. No toxicity was observed and only minor inflammatory changes were observed at the injection site 30 days later. CONCLUSION We demonstrate that a low dose of a macromolecular magnetic resonance contrast agent can provide rapid imaging of the deep lymphatic system in both small and large animals. This data provides a basis to consider a similar agent in clinical trials.

Outcome predictors and implications for management of scimitar syndrome.

BACKGROUND Scimitar syndrome is a rare congenital anomaly. We evaluated risk factors for postoperative pulmonary vein stenosis or death and predictive factors for survival without scimitar vein surgery in patients with scimitar syndrome. METHODS The records of patients with scimitar syndrome evaluated at our medical center between 1964 and 2011 were reviewed. RESULTS Scimitar syndrome was identified in 80 patients, with a median follow-up of 4.5 years. Patients presenting less than 1 year of age had a higher incidence of symptoms, aortopulmonary collaterals, coexisting congenital heart disease (CHD), extracardiac anomalies, and pulmonary hypertension. Of 36 patients having scimitar vein surgery, 18 had postoperative pulmonary vein obstruction that occurred with similar frequency after baffle or reimplantation procedures, early or late in the study period, and tended to be more common in infants (P = .10). Overall, 19 (24%) of 80 died. Multivariate risk factors for death included systolic pulmonary pressure >0.5 systemic level (P = .007) and left pulmonary vein stenosis (P = .009). Pulmonary artery systolic pressure <0.5 systemic level (P = .01) and absence of CHD excluding atrial septal defect (P = .01) were predictive factors in 28 patients who survived and did not have scimitar vein surgery; these patients had no or mild right ventricular dilation and a ratio of pulmonary-to-systemic flow <1.6 either at baseline, after coiling aortopulmonary collaterals or nonscimitar vein intervention. CONCLUSIONS Postoperative pulmonary vein obstruction is common after scimitar vein surgery regardless of redirection technique. Pulmonary hypertension and left pulmonary vein stenosis are risk factors for death, whereas patients without significant pulmonary hypertension or associated CHD did well without scimitar vein surgery. These observations may guide management decisions in patients with scimitar syndrome.

Crohn's jejunoileitis: The pediatrician's perspective on diagnosis and management

&NA; Although uncommon, diffuse jejunoilietis is one of the most difficult areas in Crohns disease (CD) to treat. Although the exact frequency is unknown, most gastroenterologists believe that its prevalence has been underestimated and that it may have an increased incidence among children and young adolescents. The clinical importance of this clinical disease phenotype is the impact diffuse small bowel disease is expected to have on a childs growth and development. Moreover, patients with jejunoileitis are more likely to experience complications, including fistulization, and most commonly, intestinal obstruction. The associated morbidity and frequent need for surgical intervention renders these patients at risk for intestinal insufficiency. Although stricturoplasty has reduced the incidence of short bowel syndrome, most patients with proximal small bowel CD still require repeated surgical intervention. Jejunoileitis represents a distinct clinical phenotype within the heterogenous family of disease phenotypes considered as CD. Whether a specific genotype will be found to associate with jejunoileitis remains to be determined. Through the development of novel diagnostic techniques, including gadolinium enhanced magnetic resonance imaging (GMRI), enteroscopy, and capsule endoscopy, the mean age at diagnosis is expected to decrease. Coupled with an increase in clinical suspicion, early diagnosis may allow physicians to consider implementing aggressive immunomodulatory therapy. Future studies are needed to determine if the early detection and use of immune modulators in patients with proximal small bowel disease will improve overall quality of life and decrease the risk of nutritional and surgical comorbidity.

Computed Tomography in Congenital Heart Disease

Over the past two decades, technological improvements have significantly advanced the role of multidetector computed tomography (MDCT) in noninvasive imaging of children with congenital heart disease (CHD). From the early use of helical CT for imaging congenital anomalies of the extracardiac thoracic vasculature (Hopkins et al. 1996; Westra et al. 1999), MDCT has become an important complementary modality to echocardiography and magnetic resonance imaging (MRI) for the morphologic evaluation of CHD (Goo et al. 2003). In addition, MDCT can now be used to assess coronary artery anatomy, measure regional and global cardiac function (Juergens et al. 2004), and provide morphologic and functional evaluation following operative and catheter intervention for many forms of congenital heart disease (Kawano et al. 2000). MDCT has rapidly evolved to systems which generate isotropic volume data and there are now much improved and faster post-processing techniques for visualizing the vasculature as compared with previously used methods.

Magnetic Resonance Lymphography of the Thoracic Duct after Interstitial Injection of Gadofosveset Trisodium: A Pilot Dosing Study in a Porcine Model

UNLABELLED BACKGROUND-RATIONALE: To investigate whether interstitial injection of gadofosveset trisodium (Ablavar®, Lantheus Medical, North Billerica, MA) would be suitable for thoracic duct (TD) imaging in a pig model. METHODS AND RESULTS Gadofosveset trisodium alone or premixed with 10% human serum albumin (HSA) was administered intradermally in the extremities of pigs at varying doses to visualize the TD by MRI. Two blinded readers evaluated MRIs for TD visibility. The inter-observer variability for all MR imaging sessions was assessed using the Spearman rank correlation test. MR lymphography using gadofosveset trisodium premixed with HSA yielded superior visualization of the TD compared to gadofosveset trisodium alone, with a high inter-observer agreement (correlation coefficient of 0.88 (p=0.00000115)). CONCLUSIONS We demonstrate that gadofosveset trisodium (premixed with 10%HSA) can be injected intradermally in order to perform MR lymphography of the thoracic duct. Since this agent is already FDA approved for MR imaging, the off-label use of it for imaging of the thoracic duct in humans is feasible, and the approach may prove to be beneficial for patients with TD abnormalities.

Cardiac MR imaging: from physics to protocols.

Cardiac MRI is now an established complementary noninvasive imaging modality to cardiac echocardiography and catheterization for the evaluation of congenital and acquired heart disease in children. Ongoing technical advances in cardiac MRI with new and improved sequences and coils have greatly improved image quality in small children. Cardiac MRI is now routinely used to obtain important anatomic, functional and hemodynamic information for treatment planning of an ever broadening number of indications including the initial evaluation of many forms of congenital heart disease or following a wide variety of corrective and palliative surgeries and catheter interventions. This paper will review the pulse sequences most often employed for evaluation of intra and extracardiac morphology, quantification of ventricular function and blood flow and coronary artery and myocardial viability assessment. Tailored protocols for common indications for cardiovascular MR will then be reviewed. Every cardiovascular MR examination begins with a review of available prior clinical and surgical history and imaging data for each patient. The goal is to tailor the examination to answer the specific questions posed by the referring cardiologist and perform the exam as efficiently as possible to keep scan times at a minimum, usually aiming for less than 1 h. The majority of patients under 8 years referred for cardiac MRI will require general anesthesia with endotracheal intebation for sequences with breath-holding or deep sedation intravenously and modification of the MR sequences for free-breathing. The choice between using general anesthesia and intravenous sedation can be different due to varying institutional guidelines and practice patterns of anesthesiologists and currently either method can be used quite successfully within a given clinical facility. [1–4]

Pediatric Cardiac CT

Recent improvements in technology have significantly advanced the role of multidetector CT (MDCT) in noninvasive imaging of the cardiovascular system. From the early use of helical CT for imaging anomalies of the thoracic vasculature (Hopkins et al. 1996; Westra et al. 1999), MDCT has become an important complementary modality to echocardiography and MRI for noninvasive imaging of cardiac morphology and function (Juergens et al. 2004), coronary arteries (Schoepf et al. 2004; Schoenhagen et al. 2004) and following operative and catheter intervention of many forms of congenital heart disease (Kawano et al. 2000). From the development of the first scanner in 1992 with 2 detectors that could acquire spatial information simultaneously, MDCT rapidly evolved to systems with 16 detectors, and presently 64 detector scanners are widely in use. A multidetector CT with ‘x’ number of detectors can obtain ‘x’ times more data per revolution than single detector systems, and current MDCT scanners have gantries that can spin faster than two revolutions per second, further increasing the speed of data acquisition.