摘要:
A system and method for analyzing a subject using a magnetic resonance imaging (MRI) system is provided. The technique includes positioning a subject within the MRI system and coupling a driver to the subject to impart vibrational energy to the subject. The technique further includes using the MRI system and in coordination with operation of the driver, acquiring medical imaging data from the subject's brain and deriving stiffness information of the subject's brain from the medical imaging data. A report, such as an image, can be provided indicating the stiffness information of the subject's brain relative to baseline stiffness information to indicate a status of the subject with respect to a neurodegenerative disease.
摘要:
An MRI image is corrected for motion artifacts using an iterative, autocorrection process in which corrections are tried and the quality of the resulting reconstructed image is measured. Different metrics for evaluating image quality are used during the autocorrection process to take advantage of their different attributes.
摘要:
An MRI image acquired with a phase-array coil is corrected for motion artifacts using an iterative, autocorrection process in which corrections are tried and the quality of the resulting reconstructed image is measured. In one embodiment autocorrections are calculated for the data acquired with one coil element and the same corrections are made to data acquired with the other coil elements. In another embodiment autocorrections are calculated separately for the data acquired with each coil element. In either embodiment, the separate corrected images are combined to form the output image.
摘要:
A three-dimensional image data set is acquired with an MRI system and autocorrected to reduce artifacts caused by subject motion during image acquisition. Correction for motion along one or two axes is performed by selecting a 2D slice of data and autocorrecting it to produce phase corrections that are then made to the entire 3D image data set. This may be repeated by autocorrecting an additional 2D slice perpendicular to the first 2D slice to produce phase corrections for the 3D image data set for motion along the third axis.
摘要:
Navigator echo signals are acquired during an MRI scan in which image data is acquired. The navigator echo signals are used to estimate an initial correction of the acquired image data for patient motion during the scan. The initially corrected image data is then autocorrected in an iterative process which measures image quality and makes further corrections to the image data until the measured image quality is within tolerance.
摘要:
A system and method for generating a magnetic resonance elastography (MRE) report includes a) acquiring MRE data from a subject including positively motion encoded medical imaging data and negatively motion encoded medical imaging data and b) deriving uncorrected difference medical imaging data from the MRE data for a given slice. The method also includes c) filtering the uncorrected difference medical imaging data to create filtered medical imaging data corrected for errors associated with phase ramps occurring during gradient switching used to derive the positively motion encoded medical imaging data and negatively motion encoded medical imaging data, d) generating a corrected difference image for the given slice from the filtered medical imaging data and the uncorrected difference medical imaging data, e) repeating steps b) through d) for each slice reflected in the MRE data, and f) generating a report of elastic properties of the subject from the corrected difference image.
摘要:
A system and method for generating a magnetic resonance elastography (MRE) report includes a) acquiring MRE data from a subject including positively motion encoded medical imaging data and negatively motion encoded medical imaging data and b) deriving uncorrected difference medical imaging data from the MRE data for a given slice. The method also includes c) filtering the uncorrected difference medical imaging data to create filtered medical imaging data corrected for errors associated with phase ramps occurring during gradient switching used to derive the positively motion encoded medical imaging data and negatively motion encoded medical imaging data, d) generating a corrected difference image for the given slice from the filtered medical imaging data and the uncorrected difference medical imaging data, e) repeating steps b) through d) for each slice reflected in the MRE data, and f) generating a report of elastic properties of the subject from the corrected difference image.
摘要:
A method for eliminating flow, motion and aliasing artifacts includes a series of saturation pulse sequences which are interleaved with the NMR pulse sequences used to acquire the data needed to reconstruct the desired image. Whereas, the NMR pulse sequences extract data from the volume of interest to be imaged, the saturation pulse sequences excite and saturate spins in the adjacent regions.
摘要:
Devices for producing an oscillatory shear stress within an object positioned in a polarizing magnetic field of an NMR imaging system are used to perform MR elastography. In one embodiment shear stress is produced within the brain by vibrating the entire skull with a transducer that is gripped by the patient's teeth.
摘要:
Motion artifacts are selectively suppressed in an image by correcting only the NMR data in the central views. The peripheral views are not corrected with the result that motion artifacts produced by large objects in the image are suppressed while motion artifacts produced by small objects are not. Consequently, the interior of small blood vessels remain darker in the reconstructed image.