摘要:
The present invention relates to a system for disrupting blood-brain barrier of a subject, comprising a transcranial magnetic stimulation device having a mode of operation which effects a blood-brain barrier disruption.
摘要:
The disclosed invention is a method for detecting indications of the presence of Alzheimer's disease (AD) and related dementia-inducing, motor-control-related pathologies, and other diseases in the human brain using a magnetic-resonance based technique for measuring fine tissue and bone textures. Specifically, the invention focuses on refinements/adaptations to a prior art magnetic resonance fine texture measurement technique that facilitates/enables pushing the detection limits closer to the cellular level, so as to be able to measure the fine scale structures and tissue changes that are known to be characteristic of the neurodegenerative processes involved in the development of these diseases.
摘要:
Featured are a device with localized sensitivity to magnetic resonance signals, an imaging system using such a device and MRI methods for performing internal MRI or MRI Endoscopy. Such an MRI method includes introducing an MRI antenna or probe into the specimen to be imaged, the antenna being configured in accordance with the devices described herein, so that the spatial coordinate frame of imaging is inherently locked or defined with respect to the introduced antenna thereby providing imaging of the specimen from the point of view of the antenna. Further such imaging is conducted so that the MRI signal is confined substantially to a volume with respect to a particular region of the antenna or probe.
摘要:
A multicoil NMR data acquisition apparatus and processing method for performing three-dimensional magnetic resonance imaging in a static magnetic field without the application of controlled static magnetic field gradients. A preferred application relates specifically to the detection and localization of groundwater using the Earth's magnetic field. Multicoil arrays are used in both transmit and receive modes, and coherent data processing algorithms applied to the data to generate three-dimensional NMR spin density estimates. Disclosed are methods for acquiring NMR data using an array of at least two transmit and receive coils, and for processing such multicoil data to estimate the three-dimensional NMR spin density distributions.
摘要:
Ein Magnetresonanz-Verfahren zur Anwendung von Hochfrequenzpulsen für eine räumlich und frequenzselektive oder mehrdimensional räumlich selektive Anregung eines Ensembles von Kernspins mit einer Ausgangsmagnetisierungsverteilung in einem entlang einer z-Achse ausgerichteten Hauptmagnetfeld, wobei eine Spinmagnetisierung mit einer vorgegebenen Zielmagnetisierungsverteilung erzeugt wird, und für eine Refokussierung der Spinmagnetisierung, ist dadurch gekennzeichnet, dass der Hochfrequenzpuls als eine Sequenz von Teilpulsen unabhängiger Dauern, Gradientenverläufen sowie räumlicher und/oder spektraler Auflösung angewendet wird, umfassend einen oder mehrere Großwinkel-HF-Pulse mit Flipwinkeln größer oder ungefähr gleich 15°, die eine grobe Magnetisierungsverteilung erzeugen, die die Zielmagnetisierungsverteilung oder eine gewünschte Magnetisierungsverteilungsänderung mit einer mittleren Abweichungen kleiner oder ungefähr gleich 15° annähert, wobei die tatsächliche Auswirkung der GWP auf die Verteilung der Spinmagnetisierung vor der Anwendung des Hochfrequenzpulses durch Integration der Bloch-Gleichungen ohne Kleinwinkelnäherung berechnet wird, und einen oder mehrere Kleinwinkel-HF-Pulse mit Flipwinkeln kleiner oder ungefähr gleich 15°, die eine Verringerung des Unterschieds zwischen der Zielmagnetisierungsverteilung und der durch die GWP bedingten groben Magnetisierungsverteilung bewirken.
摘要:
A common method of RF encoding assumes that the Bi field generated by the RF coils is linear, which is likely not the case in many situations. It is therefore desirable to have a method of operating an MR system to reconstruct an image of a subject, wherein the method is capable of also handling arbitrary Bi fields used for RF encoding. Accordingly, such an MR system employing one or more RF coils is disclosed herein. The method comprises obtaining transmit sensitivities and weighting factors for individual RF coils. Each RF coil is activated based on its respective weighting factor to apply RF excitation to a subject under examination in the MR system. MR signals - such as free induction decays (FID) signals or echo signals - generated from the subject in response to the RF excitation are received and processed based on the transmit sensitivities to generate an MR image or spectrum representative of the subject.
摘要:
Method and apparatus for treating a sample to acquire multidimensional spectra within a single scan that partitions a sample into a set of independent subensembles endowed with different resonance frequencies. A polychromatic irradiation of the sample is implemented whereby the various subensembles are selectively manipulated by a time-incremented series of excitation or refocusing sequences. Thereafter, a homogeneous sequence capable of generating an observable spectral signal from each of the subensembles is applied with simultaneous monitoring of the observable signals arising from the various subensembles in a resolved fashion. The observable signals acquired in this manner are processed into a complete multidimensional spectral data set.
摘要:
The disclosed innovation is a method for acquiring spatial frequency spectra from specific locations in a 3D sample using modifications of the current MRI techniques for localized NMR spectroscopy. The innovation in its simplest abstraction is to add the use of a read out gradient to the current NMR spectroscopy pulse sequences and record the resultant echo. These techniques generate spectra from a selected region or generate an image of the results over a region of the sample. These methods can be applied to analyzing the structure of trabecular bone as well as for analyzing or diagnosing disease in cases where there is a difference in the spatial frequency power spectrum due to physiologic or disease processes. Various embodiments are disclosed.
摘要:
The invention is a method for determination of the content of fat in a multicomponent system. The method applies nuclear magnetic resonance (NMR) for the determination of fat/oil in for example fillets of fish, olives, paint or ice cream.