Device closure of a pseudoaneurysm of the right ventricular outflow tract in an infant with right ventricle‐to‐pulmonary artery homograft

Pseudoaneurysm of the right ventricular outflow tract (RVOT) is a rare complication following surgical repair of congenital heart disease involving a homograft or conduit. Traditionally, surgical intervention is indicated due to risk for rupture, thrombosis, compression of adjacent structures, and infection. We describe a case of a RVOT pseudoaneurysm in a 5 kg patient that was palliated with interventional catheterization utilizing an Amplatzer Ductal Occluder with four years follow‐up. Interventional catheterization can successfully manage this complication in small patients for the long‐term and thus avoids additional surgery and delays conduit replacement. © 2013 Wiley Periodicals, Inc.     

Inter- and Intra-Subject Variability of Neuromagnetic Resting State Networks

Functional connectivity studies conducted at the group level using magnetoencephalography (MEG) suggest that resting state networks (RSNs) emerge from the large-scale envelope correlation structure within spontaneous oscillatory brain activity. However, little is known about the consistency of MEG RSNs at the individual level. This paper investigates the inter- and intra-subject variability of three MEG RSNs (sensorimotor, auditory and visual) using seed-based source space envelope correlation analysis applied to 5 min of resting state MEG data acquired from a 306-channel whole-scalp neuromagnetometer (Elekta Oy, Helsinki, Finland) and source projected with minimum norm estimation. The main finding is that these three MEG RSNs exhibit substantial variability at the single-subject level across and within individuals, which depends on the RSN type, but can be reduced after averaging over subjects or sessions. Over- and under-estimations of true RSNs variability are respectively obtained using template seeds, which are potentially mislocated due to inter-subject variations, and a seed optimization method minimizing variability. In particular, bounds on the minimal number of subjects or sessions required to obtain highly consistent between- or within-subject averages of MEG RSNs are derived. Furthermore, MEG RSN topography positively correlates with their mean connectivity at the inter-subject level. These results indicate that MEG RSNs associated with primary cortices can be robustly extracted from seed-based envelope correlation and adequate averaging. MEG thus appears to be a valid technique to compare RSNs across subjects or conditions, at least when using the current methods.