Key Parameters on the Microwave Assisted Synthesis of Magnetic Nanoparticles for MRI Contrast Agents.

Uniform iron oxide magnetic nanoparticles have been synthesized using a microwave assisted synthesis method in organic media and their colloidal, magnetic, and relaxometric properties have been analyzed after its transference to water and compared with those nanoparticles prepared by thermal decomposition in organic media. The novelty of this synthesis relies on the use of a solid iron oleate as precursor, which assures the reproducibility and scalability of the synthesis, and the microwave heating that resulted in being faster and more efficient than traditional heating methods, and therefore it has a great potential for nanoparticle industrial production. The effect of different experimental conditions such as the solvent, precursor, and surfactant concentration and reaction time as well as the transference to water is analyzed and optimized to obtain magnetic iron oxide nanoparticles with sizes between 8 and 15 nm and finally colloids suitable for their use as contrast agents on Magnetic Resonance Imaging (MRI).

Association, commissural, and projection pathways and their functional deficit reported in literature.

This study demonstrates normal white matter structures of the supratentorial system revealed by diffusion tensor imaging. Their anatomic connections and functional significance are discussed in the context of the lesion-induced deficits reported in the literature, which may not fully represent the lesion-induced effects on the white matter function and may not be entirely specific to the tract discussed. Nevertheless, understanding the most common effects of lesions on the functional connectivity provides a framework that we can use in advanced neuroimaging studies, like diffusion tensor imaging, functional magnetic resonance imaging, and positron emission tomography, and in our daily clinical practice.

Presurgical and intraoperative mapping of the motor system in congenital truncation of the precentral gyrus.

A 43-year-old man presented with a grade II astrocytoma in the left postcentral gyrus and superior parietal lobule. Preoperative functional MR imaging and diffusion tensor imaging mapped distal upper-extremity primary motor cortex and white matter, respectively, adjacent to the tumor, within a congenitally truncated precentral gyrus. Because of the congenital anomaly, this region of primary motor cortex was inaccessible to direct visualization or intraoperative electrocortical stimulation.

The role of diffusion tensor imaging in establishing the proximity of tumor borders to functional brain systems: implications for preoperative risk assessments and postoperative outcomes.

Diffusion Tensor Imaging (DTI) is a new MRI imaging technique sensitive to directional movements of water molecules, induced by tissue barriers. This provides a new form of contrast that allows the identification of functional white matter tracts within the brain, and has been proposed as a technique suitable for presurgical planning in brain tumor patients. Resection of primary brain tumors improves survival, functional performance, and the effectiveness of adjuvant therapies, provided that surgically-induced neurological deficits can be avoided.