Magnetic Resonance Imaging (MRI)

OBJECT: Low-frequency components of the spontaneous functional MR imaging signal provide information about the intrinsic functional and anatomical organization of the brain. The ability to use such methods in individual patients may provide a powerful tool for presurgical planning. The authors explore the feasibility of presurgical motor function mapping in which a task-free paradigm is used.

The involvement of matrix metalloproteinase-9 (MMP-9) activities in the development of abnormal water diffusion in the brain after cardiac arrest is not fully understood. We used magnetic resonance imaging to determine the correlation between MMP-9 activity and the mechanism of abnormal water diffusion after global cerebral ischemia (GCI)-induced brain damage in C57black6 mice. We induced GCI in mice by occluding both carotid arteries for 60 min, then allowing reperfusion.

We designed phosphorothioate-modified DNA probes linked to superparamagnetic iron oxide nanoparticles (SPION) for in vivo magnetic resonance imaging (MRI) of fosB and Delta fosB mRNA after amphetamine (AMPH) exposure in mice. Specificity of both the fosB and Delta fosB probes was verified by in vitro reverse transcriptase-PCR amplification to a single fragment of total cDNA obtained from acutely AMPH-exposed mouse brains. We confirmed time-dependent uptake and retention profiles of both probes in neurons of GAD67-green fluorescent protein knock-in mice.

It is well established that expectation can significantly modulate pain perception. In this study, we combined an expectancy manipulation model and fMRI to investigate how expectation can modulate acupuncture treatment. Forty-eight subjects completed the study. The analysis on two verum acupuncture groups with different expectancy levels indicates that expectancy can significantly influence acupuncture analgesia for experimental pain.

Recent advances in placebo research have demonstrated the mind's power to alter physiology. In this study, we combined an expectancy manipulation model with both verum and sham acupuncture treatments to address: 1) how and to what extent treatment and expectancy effects - including both subjective pain intensity levels (pain sensory ratings) and objective physiological activations (fMRI) - interact; and 2) if the underlying mechanism of expectancy remains the same whether placebo treatment is given alone or in conjunction with active treatment.

The macaque visual cortex contains >30 different functional visual areas, yet surprisingly little is known about the underlying organizational principles that structure its components into a complete "visual" unit. A recent model of visual cortical organization in humans suggests that visual field maps are organized as clusters. Clusters minimize axonal connections between individual field maps that represent common visual percepts, with different clusters thought to carry out different functions.

OBJECTIVE: Patients with mesial temporal lobe epilepsy (TLE) due to hippocampal sclerosis (HS) often show ictal and interictal propagation of epileptiform EEG activity to the ipsilateral temporal neocortex, the ipsilateral frontal lobe or the contralateral hippocampus, although structural MRI only shows unilateral involvement of the hippocampal formation. We used whole-head diffusion Tensor Imaging (DTI) to delineate a network that facilitates propagation of interictal epileptiform and seizure activity in this patient group.

Measurement of the blood-oxygen-level dependent (BOLD) response with fMRI has revolutionized cognitive neuroscience and is increasingly important in clinical care. The BOLD response reflects changes in deoxy-hemoglobin concentration, blood volume, and blood flow. These hemodynamic changes ultimately result from neuronal firing and synaptic activity, but the linkage between these domains is complex, poorly understood, and may differ across species, cortical areas, diseases, and cognitive states.

PURPOSE: Recent clinical trials of antivascular endothelial growth factor (VEGF) agents for glioblastoma showed promising progression-free and overall survival rates. However, available clinical imaging does not separate antitumor effects from antipermeability effects of these agents. Thus although anti-VEGF agents may decrease tumor contrast-enhancement, vascularity, and edema, the mechanisms leading to improved survival in patients remain incompletely understood. Our goal was to determine whether alleviation of edema by anti-VEGF agents alone could increase survival in mice.

Automated MRI-derived measurements of in-vivo human brain volumes provide novel insights into normal and abnormal neuroanatomy, but little is known about measurement reliability.