Uta Sboto-Frankenstein

Human cervical spinal cord funiculi: investigation with magnetic resonance diffusion tensor imaging.

To use spinal cord diffusion tensor imaging (DTI) for investigating human cervical funiculi, acquire axial diffusion magnetic resonance imaging (MRI) data with an in‐plane resolution sufficient to delineate subquadrants within the spinal cord, obtain corresponding DTI metrics, and assess potential regional differences.

Diffusion abnormality maps in demyelinating disease: Correlations with clinical scores

BACKGROUND AND PURPOSE Magnetic resonance imaging (MRI) has been explored as a noninvasive tool to assess pathology in multiple sclerosis (MS) patients. However, the correlation between classical MRI measures and physical disability is modest in MS. The diffusion tensor imaging (DTI) MRI technique holds particular promise in this regard. The present study shows brain regions where FA and individual diffusivities abnormalities are present and check their correlations with physical disability clinical scores. METHODS Eight patients and 12 matched healthy controls were recruited. The Multiple Sclerosis Functional Composite was administered. For MR-DTI acquisitions, a Genesis Signa 1.5 T MR system, an EP/SE scanning sequence, 25 gradient directions were used. RESULTS Tract Based Spatial Statistics (TBSS) group comparisons showed reduced FA and increased individual diffusivities in several brain regions in patients. Significant correlations were found between FA and: EDSS, 9-HPT(NON)DOM and 25 FW score; between λ2 and: P100 (r&l), 9-HPT(NON)DOM and 25 FW; between λ3 and: 9-HPT(NON)DOM and 25 FW score. CONCLUSIONS Fractional anisotropy and individual radial diffusivities proved to be important markers of motor disabilities in MS patients when the disease duration mean and the disability scores values range are relatively high.

Default Mode Network Functional Connectivity Altered in Failed Back Surgery Syndrome

UNLABELLED The purpose of this study was to identify alterations in the default mode network of failed back surgery syndrome patients as compared to healthy subjects. Resting state functional magnetic resonance imaging was conducted at 3 Tesla and data were analyzed with an independent component analysis. Results indicate an overall reduced functional connectivity of the default mode network and recruitment of additional pain modulation brain regions, including dorsolateral prefrontal cortex, insula, and additional sensory motor integration brain regions, including precentral and postcentral gyri, for failed back surgery syndrome patients. PERSPECTIVE This article presents alterations in the default mode network of chronic low back pain patients with failed back surgery syndrome as compared to healthy participants.

Convertible pneumatic actuator for magnetic resonance elastography of the brain.

Here we present a novel pneumatic actuator design for brain magnetic resonance elastography (MRE). Magnetic resonance elastography is a phase contrast technique capable of tracing strain wave propagation and utilizing this information for the calculation of mechanical properties of materials and living tissues. In MRE experiments, the acoustic waves are generated in a synchronized way with respect to image acquisition, using various types of mechanical actuators. The unique feature of the design is its simplicity and flexibility, which allows reconfiguration of the actuator for different applications ranging from in vivo brain MRE to experiments with phantoms. Phantom and in vivo data are presented to demonstrate actuator performance.

Tractography of Meyer's Loop asymmetries

PURPOSE The purpose of the current study was to use diffusion tensor imaging (DTI) to conduct tractography of the optic radiations (OR) and its component bundles and to assess both the degree of hemispheric asymmetry and the inter-subject variability of Meyers Loop (ML). We hypothesized that there are significant left versus right differences in the anterior extent of ML to the temporal pole (TP) in healthy subjects. MATERIALS AND METHODS DTI data were acquired on a 3T Siemens MRI system using a single-shot Spin Echo EPI sequence. The dorsal, central and ML bundles of the OR were tracked and visualized in forty hemispheres of twenty healthy volunteers. The uncinate fasciculus (UF) was also tracked in these subjects so that it could be used as a distinct anatomical reference. Measurements were derived for the distance between ML-TP, ML and the temporal horn (ML-TH) and ML and the uncinate fasciculus (ML-UF). Paired difference t-tests were carried out with SPSS 14.0. RESULTS ML and the UF were successfully tracked and visualized in all 20 volunteers. Significant hemispheric asymmetries were found for all measurements with left distances shorter than the right (P<0.005). In 50% of the subjects the left ML-UF distance was ≤1.9 mm. CONCLUSION The results support our hypothesis and demonstrate that left ML-TP distances are significantly shorter than right ML-TP distances. These asymmetries are also reflected in shorter left distances between ML-TH and ML-UF. Moreover, these results are of interest to left-sided temporal lobe epilepsy surgery because it is not only more likely to disturb the anterior extent of ML but also renders the often closely located posterior aspect of the left UF more vulnerable to potential surgical impact.

Visualization of Water Transport Pathways in Plants Using Diffusion Tensor Imaging

Magnetic resonance imaging (MRI) is a well established non-invasive technique to retrieve structural information from plants and fruits. Water transport inside these materials has also been studied with MRI, however, the integrate combination of studying both structure and dynamics has hardly been considered. Here it is shown how the anisotropic nature of water difiusion in channels or vessels inside the plant can be used to map these vessels in three dimensions. Difiusion Tensor Imaging (DTI), an MR technique initially introduced to study white matter in mammalian brains, is used to track water transport pathways inside Thompson Seedless grapes and celery as an example.

Functional MRI of the thoracic spinal cord during vibration sensation

To demonstrate that it is possible to acquire accurate functional magnetic resonance images from thoracic spinal cord neurons.

Measurement of Viscoelastic Properties of Condensed Matter using Magnetic Resonance Elastography

Measurement of Viscoelastic Properties of Condensed Matter using Magnetic Resonance Elastography Magnetic resonance elastography (MRE) is a phase contrast technique that provides a non-invasive means of evaluating the viscoelastic properties of soft condensed matter. This has a profound bio-medical significance as it allows for the virtual palpation of areas of the body usually not accessible to the hands of a medical practitioner, such as the brain. Applications of MRE are not restricted to bio-medical applications, however, the viscoelastic properties of prepackaged food products can also non-invasively be determined. Here we describe the design and use of a modular MRE acoustic actuator that can be used for experiments ranging from the human brain to pre-packaged food products. The unique feature of the used actuator design is its simplicity and flexibility, which allows easy reconfiguration.

Colour and texture processing in human extrastriate cortex: An fMRI study

Stimuli for Discrimination of Colours and Textures Each set of colour stimuli consisted of 4 Munsell colour patches (2o visual angle) matched in luminance and chroma. Within each set, hue was systematically varied so that the patches were evenly spaced in the colour domains and steps in hue were equally spaced at 2.5 perceptual steps (range 2.5-7.5 steps). For the texture task, patches of marble-like textures from Brodatz’s textures were employed. Due to the lack of a standard metric for textures, it was not possible to create equal perceptual steps for these stimuli. Methods: Behavioural Task

Symmetry of the fornix using diffusion tensor imaging.

To: 1) Present fornix tractography in its entirety for 20 healthy individuals to assess variability. 2) Provide individual and groupwise whole tract diffusion parameter symmetry assessments prior to clinical application. 3) Compare whole tract diffusion parameter assessments with tract‐based spatial statistics (TBSS).