Developing Methods to Aid Edge Detection in a Micro-Computed Tomography Based Subcutaneous Versus Visceral Fat Segmentation Algorithm

Micro-computed tomography can be used to provide a precise in-vivo assessment of adipose tissue quantity and distribution, including information on subcutaneous and visceral fat volume in mouse models. This study aims to develop methods to aid edge detection in order to eventually segment out the visceral and subcutaneous fat compartments automatically. The algorithm detailed in this paper optimizes steps in the Canny edge detection method and utilizes low-pass filtering and gradient edge detection. Ten mice (weight range: 19.96 - 57.66 g) were tested with micro-CT scans to verify the utility of this algorithm. The algorithm demonstrated stability despite the broad range of body weights and adiposity. Comparisons of the data between unfiltered versus filtered mice volumes suggest that this algorithm can be used to effectively increase edge strength for use in separating visceral and subcutaneous fat compartments. The eventual application of this method would be to assess metabolic disease risk, such as those associated with central obesity including diabetes, hypertension, and heart disease

Cornelia de-Lange syndrome - A case report

Cornelia de-Lange syndrome (CdLS) is a rare multisystem developmental disorder characterized by psychomotor retardation and delayed growth associated with a series of malformations, including facial dysmorphia, upper-extremity malformations, hirsutism, cardiac defects, and gastrointestinal abnormalities. There is no definitive biochemical or chromosomal marker for the prenatal diagnosis of syndrome so it is important for the clinician to know etiopathological aspects and characteristic features to provide health care and help improve the quality of life of affected individuals

Resting-State Networks and the Functional Connectome of the Human Brain in Agenesis of the Corpus Callosum

The corpus callosum is the largest white matter fiber bundle connecting the two cerebral hemispheres. In this work, we investigate the effect of callosal dysgenesis on functional magnetic resonance imaging (fMRI) resting-state networks and the functional connectome. Since alternate commissural routes between the cerebral hemispheres exist, we hypothesize that bilateral cortical networks can still be maintained in partial or even complete agenesis of the corpus callosum (AgCC). However, since these commissural routes are frequently indirect, requiring polysynaptic pathways, we hypothesize that quantitative measurements of interhemispheric functional connectivity in bilateral networks will be reduced in AgCC compared with matched controls, especially in the most highly interconnected cortical regions that are the hubs of the connectome. Seventeen resting-state networks were extracted from fMRI of 11 subjects with partial or complete AgCC and 11 matched controls. The results show that the qualitative organization of resting-state networks is very similar between controls and AgCC. However, interhemispheric functional connectivity of precuneus, posterior cingulate cortex, and insular-opercular regions was significantly reduced in AgCC. The preserved network organization was confirmed with a connectomic analysis of the resting-state fMRI data, showing five functional modules that are largely consistent across the control and AgCC groups. Hence, the reduction or even complete absence of callosal connectivity does not affect the qualitative organization of bilateral resting-state networks or the modular organization of the functional connectome, although quantitatively reduced functional connectivity can be demonstrated by measurements within bilateral cortical hubs, supporting the hypothesis that indirect polysynaptic pathways are utilized to preserve interhemispheric temporal synchrony

Resting-State Networks and the Functional Connectome of the Human Brain in Agenesis of the Corpus Callosum

The corpus callosum is the largest white matter fiber bundle connecting the two cerebral hemispheres. In this work, we investigate the effect of callosal dysgenesis on functional magnetic resonance imaging (fMRI) resting-state networks and the functional connectome. Since alternate commissural routes between the cerebral hemispheres exist, we hypothesize that bilateral cortical networks can still be maintained in partial or even complete agenesis of the corpus callosum (AgCC). However, since these commissural routes are frequently indirect, requiring polysynaptic pathways, we hypothesize that quantitative measurements of interhemispheric functional connectivity in bilateral networks will be reduced in AgCC compared with matched controls, especially in the most highly interconnected cortical regions that are the hubs of the connectome. Seventeen resting-state networks were extracted from fMRI of 11 subjects with partial or complete AgCC and 11 matched controls. The results show that the qualitative organization of resting-state networks is very similar between controls and AgCC. However, interhemispheric functional connectivity of precuneus, posterior cingulate cortex, and insular-opercular regions was significantly reduced in AgCC. The preserved network organization was confirmed with a connectomic analysis of the resting-state fMRI data, showing five functional modules that are largely consistent across the control and AgCC groups. Hence, the reduction or even complete absence of callosal connectivity does not affect the qualitative organization of bilateral resting-state networks or the modular organization of the functional connectome, although quantitatively reduced functional connectivity can be demonstrated by measurements within bilateral cortical hubs, supporting the hypothesis that indirect polysynaptic pathways are utilized to preserve interhemispheric temporal synchrony

Keys to the kingdom

FWN – Publicaties zonder aanstelling Universiteit Leide