Discriminating cancer from noncancer tissue in the prostate by 3-dimensional proton magnetic resonance spectroscopic imaging: a prospective multicenter validation study.

Objectives: A prospective multicenter validation of the ability of 1H magnetic resonance spectroscopic imaging (MRSI) to distinguish cancer from noncancer tissues throughout the prostate with histopathology of the resected organ as the standard of reference.

Materials And Methods: Institutional review board approval was obtained for all centers and all participating patients and volunteers provided written informed consent. Ninety-nine patients and 10 age-matched volunteers from 8 participating centers underwent magnetic resonance imaging and 3-dimensional MRSI with an endorectal coil at 1.

Matrix-binding vascular endothelial growth factor (VEGF) isoforms guide granule cell migration in the cerebellum via VEGF receptor Flk1.

Vascular endothelial growth factor (VEGF) regulates angiogenesis, but also has important, yet poorly characterized roles in neuronal wiring. Using several genetic and in vitro approaches, we discovered a novel role for VEGF in the control of cerebellar granule cell (GC) migration from the external granule cell layer (EGL) toward the Purkinje cell layer (PCL). GCs express the VEGF receptor Flk1, and are chemoattracted by VEGF, whose levels are higher in the PCL than EGL.

Anterior cruciate ligament deficiency causes brain plasticity: a functional MRI study.

Background: The mechanoreceptors located in anterior cruciate ligament (ACL) constitute an afferent source of information toward the central nervous system. It has been proposed that ACL deficiency causes a disturbance in neuromuscular control, affects central programs and consequently the motor response resulting in serious dysfunction of the injured limb.

Purpose: The objective of this study was to investigate whether chronic anterior cruciate ligament injury causes plastic changes in brain activation patterns.

Deficiency or inhibition of oxygen sensor Phd1 induces hypoxia tolerance by reprogramming basal metabolism.

HIF prolyl hydroxylases (PHD1-3) are oxygen sensors that regulate the stability of the hypoxia-inducible factors (HIFs) in an oxygen-dependent manner. Here, we show that loss of Phd1 lowers oxygen consumption in skeletal muscle by reprogramming glucose metabolism from oxidative to more anaerobic ATP production through activation of a Pparalpha pathway. This metabolic adaptation to oxygen conservation impairs oxidative muscle performance in healthy conditions, but it provides acute protection of myofibers against lethal ischemia.

Frequency-selective quantitation of short-echo time 1H magnetic resonance spectra.

Accurate and efficient filtering techniques are required to suppress large nuisance components present in short-echo time magnetic resonance (MR) spectra. This paper discusses two powerful filtering techniques used in long-echo time MR spectral quantitation, the maximum-phase FIR filter (MP-FIR) and the Hankel-Lanczos Singular Value Decomposition with Partial ReOrthogonalization (HLSVD-PRO), and shows that they can be applied to their more complex short-echo time spectral counterparts. Both filters are validated and compared through extensive simulations.

Lower limb sensorimotor network: issues of somatotopy and overlap.

Functional magnetic resonance imaging (fMRI) was used (1) to describe the pattern of whole brain activity during motion of isolated joints of the lower limb, (2) to examine the somatotopic organization of lower limb joint representations in the primary sensorimotor cortex and the anterior lobe of the cerebellum and 3) to quantify the degree of overlap between these lower limb joint activations. Eighteen healthy, right leg dominant volunteers participated in a motor block-design study, performing repetitive knee, ankle and toes flexion/extension movements. In order to relate lower limb joints activation to the well-described patterns of finger movement, serial finger-to-thumb opposition was also assessed.

Lateralization of functional magnetic resonance imaging (fMRI) activation in the auditory pathway of patients with lateralized tinnitus.

Introduction: Tinnitus is hypothesized to be an auditory phantom phenomenon resulting from spontaneous neuronal activity somewhere along the auditory pathway. We performed fMRI of the entire auditory pathway, including the inferior colliculus (IC), the medial geniculate body (MGB) and the auditory cortex (AC), in 42 patients with tinnitus and 10 healthy volunteers to assess lateralization of fMRI activation.

Methods: Subjects were scanned on a 3T MRI scanner.

A 3 T event-related functional magnetic resonance imaging (fMRI) study of primary and secondary gustatory cortex localization using natural tastants.

Introduction: It is known that taste is centrally represented in the insula, frontal and parietal operculum, as well as in the orbitofrontal cortex (secondary gustatory cortex). In functional MRI (fMRI) experiments activation in the insula has been confirmed, but activation in the orbitofrontal cortex is only infrequently found, especially at higher field strengths (3 T). Due to large susceptibility artefacts, the orbitofrontal cortex is a difficult region to examine with fMRI.

Lateralization of brain activity during lower limb joints movement. An fMRI study.

Studies of unilateral finger movement in right-handed subjects have shown asymmetrical patterns of activation in primary motor cortex and subcortical regions. In order to investigate the existence of an analogous pattern during lower limb joints movements, functional magnetic resonance imaging (fMRI) was used. Eighteen healthy, right leg dominant volunteers participated in a motor block design study, performing unilateral right and left repetitive knee, ankle and toes flexion/extension movements.

Word reading and posterior temporal dysfunction in amnestic mild cognitive impairment.

Patient studies that combine functional magnetic resonance imaging with chronometric analysis of language dysfunction may reveal the critical contribution of brain areas to language processes as well as shed light on disease pathogenesis. In amnestic mild cognitive impairment (MCI), a prodromal stage of Alzheimer's disease, we examined whether the brain system for associative-semantic judgments with words or with pictures is affected and how this relates to off-line chronometric analysis of word reading and picture naming. A consecutive memory clinic-based series of 13 amnestic MCI patients as well as 13 matched controls participated.

Magnetization transfer imaging in chronic schizophrenia.

Background: It has recently been suggested that new imaging methods such as magnetization transfer imaging (MTI) may play an important role in detecting subtle gray- and white-matter abnormalities in schizophrenia. The aim of the study was to investigate whether MTI, analyzed on a voxel-by-voxel basis, could identify areas of abnormal magnetization transfer ratio (MTR) in patients with schizophrenia.

Material/methods: Twenty schizophrenic patients and 23 healthy controls matched for handedness and demographic variables underwent MTI and T1-weighted structural MRI in a 3-tesla scanner.

Liver tumor model with implanted rhabdomyosarcoma in rats: MR imaging, microangiography, and histopathologic analysis.

In compliance with institutional regulations for care and use of laboratory animals, the aim of this study was to establish and characterize a rodent liver tumor model to provide a platform for preclinical assessment of new diagnostic and therapeutic strategies. A rhabdomyosarcoma tumor was implanted in the right and left liver lobes of 20 rats, for a total of 40 tumors. T1- and T2-weighted magnetic resonance (MR) images, diffusion-weighted images, and dynamic susceptibility contrast agent-enhanced perfusion-weighted images were obtained up to 16 days after tumor implantation and were compared with postmortem three-dimensional computed tomographic (CT) images, digital microangiograms, and histopathologic findings.

Activation of cortical and subcortical auditory structures at 3 T by means of a functional magnetic resonance imaging paradigm suitable for clinical use.

Objectives: Visualization of functional magnetic resonance imaging (fMRI) activation of subcortical auditory structures remains challenging because of the cardiac-related pulsatile movement of both the brainstem and the cerebrospinal fluid and involved, until now, special scanning, pre- and postprocessing techniques, which are not convenient in clinical settings. The aim of this study is to examine the activation in both cortical and subcortical auditory structures by means of an fMRI paradigm, which is suitable for clinical use.

Materials And Methods: Twenty subjects (13 volunteers and 7 patients) were examined on a 3 T imaging system with binaural musical stimulation.

Tissue segmentation and classification of MRSI data using canonical correlation analysis.

In this article an accurate and efficient technique for tissue typing is presented. The proposed technique is based on Canonical Correlation Analysis, a statistical method able to simultaneously exploit the spectral and spatial information characterizing the Magnetic Resonance Spectroscopic Imaging (MRSI) data. Recently, Canonical Correlation Analysis has been successfully applied to other types of biomedical data, such as functional MRI data.

Mapping multiple visual areas in the human brain with a short fMRI sequence.

It is a fundamental insight of neuroscience that the cerebral cortex is divided into spatially separated and functionally distinct areas. In this study, we tried to map a large number of visual areas in individual subjects passively viewing a simple stimulus sequence during functional magnetic resonance imaging (fMRI) at 1.5 T.

Anterior temporal laterality in primary progressive aphasia shifts to the right.

In aphasia due to stroke, language-related activity shifts not only to undamaged cortex within the dominant hemisphere but also toward right-sided areas homotopical to the left-sided lesion. We examined whether a rightward shift takes place in primary progressive aphasia (PPA). Nineteen PPA patients participated, 19 healthy subjects and 14 patients with amnestic mild cognitive impairment who served as controls.

Quantitative diffusion tensor imaging in cerebral palsy due to periventricular white matter injury.

Periventricular white matter injury (PWI) is a major form of brain injury observed in congenital hemiparesis. The aim of this study is to determine the usefulness of diffusion tensor imaging (DTI) and fibre tracking in delineating the primary and secondary degenerative changes in cerebral white matter and deep grey matter in patients with spastic cerebral palsy due to PWI and to look for any possible reorganization of the axonal architecture. Five hemiparetic cerebral palsy patients (median age 14 years) with known PWI were prospectively studied with DTI of the brain at 1.

Passive somatosensory discrimination tasks in healthy volunteers: differential networks involved in familiar versus unfamiliar shape and length discrimination.

Somatosensory discrimination of unseen objects relies on processing of proprioceptive and tactile information to detect spatial features, such as shape or length, as acquired by exploratory finger movements. This ability can be impaired after stroke, because of somatosensory-motor deficits. Passive somatosensory discrimination tasks are therefore used in therapy to improve motor function.

Attention to 3-D shape, 3-D motion, and texture in 3-D structure from motion displays.

We used fMRI to directly compare the neural substrates of three-dimensional (3-D) shape and motion processing for realistic textured objects rotating in depth. Subjects made judgments about several different attributes of these objects, including 3-D shape, the 3-D motion, and the scale of surface texture. For all of these tasks, we equated visual input, motor output, and task difficulty, and we controlled for differences in spatial attention.

Parieto-premotor areas mediate directional interference during bimanual movements.

In bimanual movements, interference emerges when limbs are moved simultaneously along incompatible directions. The neural substrate and mechanisms underlying this phenomenon are largely unknown. We used functional magnetic resonance imaging to compare brain activation during directional incompatible versus compatible bimanual movements.

Color discrimination involves ventral and dorsal stream visual areas.

We used positron emission tomography (PET) and functional magnetic resonance imaging (fMRI) in human subjects to investigate whether the ventral and dorsal visual stream cooperate when active judgements about color have to be made. Color was used as the attribute, because it is processed primarily in the ventral stream. The centrally positioned stimuli were equiluminant shades of brown.

Involvement of multiple functionally distinct cerebellar regions in visual discrimination: a human functional imaging study.

We investigated the contribution of the human cerebellum to cerebral function during visual discrimination using PET and fMRI. The cognitive task was a successive discrimination of shades of brown with a parametric variation of the stimulus presentation rate and a constant task difficulty. The successive color discrimination task was contrasted to a dimming detection control task, with identical retinal input but with double the number of motor responses.

Internal vs external generation of movements: differential neural pathways involved in bimanual coordination performed in the presence or absence of augmented visual feedback.

It is commonly agreed that a functional dissociation with respect to the internal vs external control of movements exists for several brain regions. This has, however, only been tested in relation to the timing and preparation of motor responses, but not to ongoing movement control. Using functional magnetic resonance imaging (fMRI), the present study addressed the neuroanatomical substrate of the internal-external control hypothesis by comparing regional brain activation for cyclical bimanual movements performed in the presence or absence of augmented visual feedback.

Beneficial effects of creatine supplementation in dystrophic patients.

The effect of creatine (Cr) supplementation on muscle function and body composition of 12 boys with Duchenne muscular dystrophy and three with Becker dystrophy was evaluated by a randomized double-blind cross-over study (3 g Cr or maltodextrin daily for 3 months, with wash-out period of 2 months). After placebo, no change was observed in maximal voluntary contraction (MVC) and resistance to fatigue, whereas total joint stiffness (TJS) was increased by approximately 25% (P < 0.05).