Stitcher: A Surface Reconstruction Tool for Highly Gyrified Brains.

Brain reconstruction, specially of the cerebral cortex, is a challenging task and even more so when it comes to highly gyrified brained animals. Here, we present Stitcher, a novel tool capable of generating such surfaces utilizing MRI data and manual segmentation. Stitcher makes a triangulation between consecutive brain slice segmentations by recursively adding edges that minimize the total length and simultaneously avoid self-intersection.

Central Vein Sign and Paramagnetic Rim Lesions: Susceptibility Changes in Brain Tissues and Their Implications for the Study of Multiple Sclerosis Pathology.

Multiple sclerosis (MS) is the most common acquired inflammatory and demyelinating disease in adults. The conventional diagnostic of MS and the follow-up of inflammatory activity is based on the detection of hyperintense foci in T2 and fluid-attenuated inversion recovery (FLAIR) magnetic resonance imaging (MRI) and lesions with brain-blood barrier (BBB) disruption in the central nervous system (CNS) parenchyma. However, T2/FLAIR hyperintense lesions are not specific to MS and the MS pathology and inflammatory processes go far beyond focal lesions and can be independent of BBB disruption.

Anatomical and volumetric description of the guiana dolphin (Sotalia guianensis) brain from an ultra-high-field magnetic resonance imaging.

The Guiana dolphin (Sotalia guianensis) is a common species along Central and South American coastal waters. Although much effort has been made to understand its behavioral ecology and evolution, very little is known about its brain. The use of ultra-high field MRI in anatomical descriptions of cetacean brains is a very promising approach that is still uncommon.

Left-sided epileptiform activity influences language lateralization in right mesial temporal sclerosis.

Objective: To investigate the association between left epileptiform activity and language laterality indices (LI) in patients with right mesial temporal sclerosis (MTS).

Methods: Twenty-two patients with right MTS and 22 healthy subjects underwent fMRI scanning while performing a language task. LI was calculated in multiple regions of interest (ROI).

Novel Gadolinium-Free Ultrasmall Nanostructured Positive Contrast for Magnetic Resonance Angiography and Imaging.

Nanostructured contrast agents are promising alternatives to Gd-based chelates in magnetic resonance (MR) imaging techniques. A novel ultrasmall paramagnetic nanoparticle (UPN) was strategically designed to maximize the number of exposed paramagnetic sites and while minimizing , by decorating 3 nm titanium dioxide nanoparticles with suitable amounts of iron oxide. Its relaxometric parameters are comparable to those of gadoteric acid (GA) in agar phantoms, and the / ratio of 1.

Evaluation of multi-channel phase reconstruction methods for quantitative susceptibility mapping on postmortem human brain.

Quantitative Susceptibility Mapping (QSM) is an established Magnetic Resonance Imaging (MRI) technique with high potential in brain iron studies associated to several neurodegenerative diseases. Unlike other MRI techniques, QSM relies on phase images to estimate tissue's relative susceptibility, therefore requiring a reliable phase data. Phase images from a multi-channel acquisition should be reconstructed in a proper way.

Decompose quantitative susceptibility mapping (QSM) to sub-voxel diamagnetic and paramagnetic components based on gradient-echo MRI data.

Purpose: A method named DECOMPOSE-QSM is developed to decompose bulk susceptibility measured with QSM into sub-voxel paramagnetic and diamagnetic components based on a three-pool complex signal model.

Methods: Multi-echo gradient echo signal is modeled as a summation of three weighted exponentials corresponding to three types of susceptibility sources: reference susceptibility, diamagnetic and paramagnetic susceptibility relative to the reference. Paramagnetic component susceptibility (PCS) and diamagnetic component susceptibility (DCS) maps are constructed to represent the sub-voxel compartments by solving for linear and nonlinear parameters in the model.

Posterior cingulate cortex/precuneus blood oxygen-level dependent signal changes during the repetition of an attention task in meditators and nonmeditators.

Background And Purpose: Among several cognitive advantages, meditation is thought to enhance practitioners' capacity for sustained attention. In the present study, we explored this question by testing meditation practitioners (meditators) and nonpractitioners (nonmeditators) on a task that requires sustained attention, the Stroop Word-Color Task (SWCT), while using functional MRI.

Participants And Methods: Participants were all right-handed and included 23 regular meditators as well as 17 nonmeditators.

Effects of a 7-Day Meditation Retreat on the Brain Function of Meditators and Non-Meditators During an Attention Task.

Meditation as a cognitive enhancement technique is of growing interest in the field of health and research on brain function. The Stroop Word-Color Task (SWCT) has been adapted for neuroimaging studies as an interesting paradigm for the understanding of cognitive control mechanisms. Performance in the SWCT requires both attention and impulse control, which is trained in meditation practices.

Corpus callosum diffusion abnormalities in refractory epilepsy associated with hippocampal sclerosis.

Objectives: To detect by diffusion tensor imaging (DTI) the extent of microstructural integrity changes of the corpus callosum (CC) in patients with hippocampal sclerosis (HS) and to evaluate possible association with clinical characteristics.

Methods: Fourty-two patients with temporal lobe epilepsy (TLE) and HS and 30 control subjects were studied with DTI. We grouped patients according to lesion side (left or right) HS.

Interictal abnormal fMRI activation of visual areas during a motor task cued by visual stimuli in migraine.

Objective: To assess changes in blood-oxygen-level-dependent activity after light deprivation compared to regular light exposure in subjects with migraine in the interictal state and in controls.

Methods: Ten subjects with migraine and ten controls participated in two sessions of functional magnetic resonance imaging. In each session, they performed a finger-tapping task with the right hand, cued by visual stimuli.

Substantia nigra fractional anisotropy is not a diagnostic biomarker of Parkinson's disease: A diagnostic performance study and meta-analysis.

Objectives: Our goal was to estimate the diagnostic accuracy of substantia nigra fractional anisotropy (SN-FA) for Parkinson's disease (PD) diagnosis in a sample similar to the clinical setting, including patients with essential tremor (ET) and healthy controls (HC). We also performed a systematic review and meta-analysis to estimate mean change in SN-FA induced by PD and its diagnostic accuracy.

Methods: Our sample consisted of 135 subjects: 72 PD, 21 ET and 42 HC.

Time-Perception Network and Default Mode Network Are Associated with Temporal Prediction in a Periodic Motion Task.

The updating of prospective internal models is necessary to accurately predict future observations. Uncertainty-driven internal model updating has been studied using a variety of perceptual paradigms, and have revealed engagement of frontal and parietal areas. In a distinct literature, studies on temporal expectations have also characterized a time-perception network, which relies on temporal orienting of attention.

Evaluation of Glaucomatous Damage via Functional Magnetic Resonance Imaging, and Correlations Thereof with Anatomical and Psychophysical Ocular Findings.

Purpose: To evaluate the functional magnetic resonance imaging (fMRI) response to binocular visual stimulation and the association thereof with structural ocular findings and psychophysical test results in patients with glaucoma, and controls.

Methods: Cross-sectional study. Participants underwent a complete ophthalmic examination, including Humphrey 24-2 visual field (VF) testing and optical coherence tomography.