Computerized method for nonrigid MR-to-PET breast-image registration

We have developed and tested a new simple computerized finite element method (FEM) approach to MR-to-PET nonrigid breast-image registration. The method requires five-nine fiducial skin markers (FSMs) visible in MRI and PET that need to be located in the same spots on the breast and two on the flanks during both scans. Patients need to be similarly positioned prone during MRI and PET scans. This is accomplished by means of a low gamma-ray attenuation breast coil replica used as the breast support during the PET scan. We demonstrate that, under such conditions, the observed FSM displacement vectors between MR and PET images, distributed piecewise linearly over the breast volume, produce a deformed FEM mesh that reasonably approximates nonrigid deformation of the breast tissue between the MRI and PET scans. This method, which does not require a biomechanical breast tissue model, is robust and fast. Contrary to other approaches utilizing voxel intensity-based similarity measures or surface matching, our method works for matching MR with pure molecular images (i.e. PET or SPECT only). Our method does not require a good initialization and would not be trapped by local minima during registration process. All processing including FSMs detection and matching, and mesh generation can be fully automated. We tested our method on MR and PET breast images acquired for 15 subjects. The procedure yielded good quality images with an average target registration error below 4 mm (i.e. well below PET spatial resolution of 6-7 mm). Based on the results obtained for 15 subjects studied to date, we conclude that this is a very fast and a well-performing method for MR-to-PET breast-image nonrigid registration. Therefore, it is a promising approach in clinical practice. This method can be easily applied to nonrigid registration of MRI or CT of any type of soft-tissue images to their molecular counterparts such as obtained using PET and SPECT.     

Spondylocostal dysostosis in a pregnancy complicated by confined placental mosaicism for tetrasomy 9p

The spondylocostal dysostoses (SCD) are a clinically and genetically heterogeneous group of disorders characterized by defects of vertebral segmentation and rib abnormalities. We report on the diagnosis of two siblings with SCD. Diagnosis was first made in a female infant following a pregnancy that was complicated by early fetal hydrops and a nuchal translucency of 8.2 mm in the first trimester. The clinical picture was complicated by the co-existent diagnosis of confined placental mosaicism (CPM) for tetrasomy 9p. To our knowledge, this is the first report of CPM for tetrasomy 9p. Postnatally the diagnosis of SCD was made on the basis of radiographic findings comprising multiple anomalies of the cervical and thoracic vertebrae and multiple fused and dysplastic ribs. Radiographic investigation of other family members showed that the infant's 4-year-old sibling had fusion of four ribs on the right side, indicating a less severe form of SCD. Testing of the genes DLL3, MESP2, and LFNG did not identify a mutation, suggesting that the siblings may have a new molecular subtype of SCD.     

Neuroanatomical changes in a mouse model of early life neglect

Using a novel mouse model of early life neglect and abuse (ENA) based on maternal separation with early weaning, George et al. (BMC Neurosci 11:123, 2010) demonstrated behavioral abnormalities in adult mice, and Bordner et al. (Front Psychiatry 2(18):1–18, 2011) described concomitant changes in mRNA and protein expression. Using the same model, here we report neuroanatomical changes that include smaller brain size and abnormal inter-hemispheric asymmetry, decreases in cortical thickness, abnormalities in subcortical structures, and white matter disorganization and atrophy most severely affecting the left hemisphere. Because of the similarities between the neuroanatomical changes observed in our mouse model and those described in human survivors of ENA, this novel animal model is potentially useful for studies of human ENA too costly or cumbersome to be carried out in primates. Moreover, our current knowledge of the mouse genome makes this model particularly suited for targeted anatomical, molecular, and pharmacological experimentation not yet possible in other species.     

Frontal dysconnectivity in 22q11.2 deletion syndrome: an atlas-based functional connectivity analysis

Background

22q11.2 deletion syndrome (22q11DS) is a neurodevelopmental syndrome associated with deficits in cognitive and emotional processing. This syndrome represents one of the highest risk factors for the development of schizophrenia. Previous studies of functional connectivity (FC) in 22q11DS report aberrant connectivity patterns in large-scale networks that are associated with the development of psychotic symptoms.

Methods

In this study, we performed a functional connectivity analysis using the CONN toolbox to test for differential connectivity patterns between 54 individuals with 22q11DS and 30 healthy controls, between the ages of 17–25 years old. We mapped resting-state fMRI data onto 68 atlas-based regions of interest (ROIs) generated by the Desikan-Killany atlas in FreeSurfer, resulting in 2278 ROI-to-ROI connections for which we determined total linear temporal associations between each. Within the group with 22q11DS only, we further tested the association between prodromal symptoms of psychosis and FC.

Results

We observed that relative to controls, individuals with 22q11DS displayed increased FC in lobar networks involving the frontal–frontal, frontal–parietal, and frontal–occipital ROIs. In contrast, FC between ROIs in the parietal–temporal and occipital lobes was reduced in the 22q11DS group relative to healthy controls. Moreover, positive psychotic symptoms were positively associated with increased functional connections between the left precuneus and right superior frontal gyrus, as well as reduced functional connectivity between the bilateral pericalcarine. Positive symptoms were negatively associated with increased functional connectivity between the right pericalcarine and right postcentral gyrus.

Conclusions

Our results suggest that functional organization may be altered in 22q11DS, leading to disruption in connectivity between frontal and other lobar substructures, and potentially increasing risk for prodromal psychosis.

     

Hypersensitivity reactions to antilipemic drugs

Chronic utilization of hipolipemiants drugs makes possible the onset of hypersensitivity reactions like a part of secondary reactions. From the point of our experience the most frequent hyperreactivity appears on fibric acid derivates. Al the cases we treated, were skin manifestations (angioedema) and about 29%, were digestive manifestations (dyspepsia, vomiting, diarrhoea). At the same time, chronic utilization of nicotinic acid derivates favored skin rash due to congestive intrinsic effect of nicotinic acid.