Patent application number | Description | Published |
20090253979 | SYSTEM AND METHOD FOR CYCLIC MOTION ENCODING FOR ENHANCED VISUALIZATION OF SLIP INTERFACES WITH MRI - A system and method for producing an image of a functional tissue slip interface using MRI. The method includes applying an external stimulus to a subject to impart relative shearing motion at a tissue interface. NMR signals are then acquired from a ROI including the slip interface using a motion encoding gradient to sensitize the acquired NMR signals to the shearing motion. MR images indicative of the degree of mechanical shear connectivity at the tissue interface are reconstructed from the acquired NMR signals in which low-friction shearing motion at the tissue interface is characterized by a loss of magnitude signal due to intravoxel phase dispersion. | 10-08-2009 |
20090295387 | Shear Wave Generation System For Medical Imaging - A system is configured to produce a stress on a subject while performing a magnetic resonance elastography scan in a magnetic resonance imaging (MRI) system. The system includes an active driver operable to produce an energy configured for a magnetic resonance elastography (MRE) process. A passive actuator is configured to be positioned in the MRI system and to be coupled to the subject. The system includes a tube coupling the active driver to the passive actuator to deliver the energy produced by the active driver to the passive actuator, and a strap coupled to the passive actuator. The strap is configured to be disposed around the subject. The strap includes a substantially inelastic material configured to convert the energy delivered to the passive actuator from the tube into shear waves with the subject for use in the MRE process. | 12-03-2009 |
20090299168 | Passive Acoustic Driver For Magnetic Resonance Elastography - An acoustic driver system for use in applying an oscillating stress to a subject undergoing a magnetic resonance elastography (MRE) examination includes a flexible passive driver located in the bore of the magnet and in contact with the subject. A remotely located active driver is acoustically coupled to the passive driver and produces acoustic energy in response to an applied current. The passive driver produces shear waves in response to the acoustic energy and are directed into the body of the subject undergoing the MRE examination. | 12-03-2009 |
20100005892 | ACTIVE ACOUSTIC DRIVER FOR MAGNETIC RESONANCE ELASTOGRAPHY - A driver for applying an oscillating stress to a subject undergoing a medical imaging procedure, such as with magnetic resonance elastography (MRE), includes a passive driver located in the bore of the magnet and in direct contact with the skin of the subject. A remotely located active driver includes a linear motor and a sealed diaphragm that produces acoustic pressure waves in response to an applied current. The pressure waves are directed through a tube and into a chamber formed within the passive driver. Vibrations produced in response to the pressure waves create shear waves that are directed into the subject to aid in the imaging procedure. | 01-14-2010 |
20100241012 | Portal Vein Pressure Measurement Using Elastography - The shear stiffness of a subject's spleen is measured using elastography techniques such as ultrasound elastography or a magnetic resonance elastography (MRE) acquisition with an MRI system. A relationship between splenic shear stiffness and portal venous blood pressure is modeled and is used to calculate portal venous blood pressure non-invasively from the measured splenic shear stiffness. | 09-23-2010 |
20110025333 | SHEAR MODE PRESSURE-ACTIVATED DRIVER FOR MAGNETIC RESONANCE ELASTOGRAPHY - A magnetic resonance elastography (“MRE”) driver that can produce shear waves in a subject without relying on mode conversion of longitudinal waves is disclosed. More specifically, the MRE driver includes a pneumatic driver located remotely from a magnetic resonance imaging (“MRI”) system which is operable in response to an applied electrical current to oscillate, a pressure-activated driver that is positioned on a subject in the MRI system, and a tube that is in fluid communication, at one end, with the pneumatic driver. The pressure-activated driver includes a base plate and a driver plate having a region between them that receives the tube. Oscillations of the pneumatic driver produce a pressure wave in the tube that causes the driver plate to vibrate. The driver plate rests against the subject of interest to apply a corresponding shear oscillatory force to the subject during the MRE examination. | 02-03-2011 |
20110060210 | METHOD FOR ASSESSING THE PROBABILITY OF DISEASE DEVELOPMENT IN TISSUE - A method for detecting conditions in tissues that can lead to disease includes an in vivo measurement of the mechanical characteristics of the tissues using Magnetic Resonance Elastography (MRE). The deviation of mechanical characteristics such as tissue stiffness from a predetermined norm is determined and indicated on an image of the tissues. | 03-10-2011 |
20110092798 | METHOD FOR MAGNETIC RESONANCE ELASTOGRAPHY INVERSION USING A FINITE MEDIUM MODEL - A method for magnetic resonance elastography (“MRE”) is described, in which an MRE inversion that accounts for waves propagating in a finite, bounded media is employed. A vibratory motion is induced in a subject and MRE is performed to measure one or more components of the resulting displacement produced in the subject. This displacement data is subsequently filtered to provide a more accurate and computationally efficient method of inversion. Wave equations based on the geometry of the bounded media are then utilized to calculate the material properties of the subject. Such a method allows for the performance of MRE on tissues such as the heart, eye, bladder, and prostate with more accurate results. | 04-21-2011 |
20120010497 | Single-Sided Magnetic Resonance Imaging System Suitable for Performing Magnetic Resonance Elastography - A unilateral magnetic resonance imaging (“MRI”) device ( | 01-12-2012 |
20120130227 | System and Method for Assessing Response to Chemotherapy Using Magnetic Resonance Elastography - A system and method for determining a response of a tumor following a chemotherapy process includes the use of a magnetic resonance elastography (MRE) driver and a magnetic resonance imaging (MRI) system. The method includes controlling the MRE driver and the MRI system to acquire raw MRE data from the tumor, inverting the raw MRE data to produce an elastogram of the tumor, and determining a response of the tumor to the chemotherapy process from the elastogram. | 05-24-2012 |
20120259201 | System and Method for Inertial Magnetic Resonance Elastography Driver for Use With Interventional Medical Device - A system and method for performing a magnetic resonance elastography (MRE) procedure using an MRI system to monitor operation of a medical device performing a medical procedure. The driver system includes a housing, a port located in the housing and connected to a driving power, and an inertial driver moved within the housing by the driving power. A passage is formed in the housing and extends from a first opening in the housing, through the inertial driver, and to a second opening in the housing. The inertial driver receives a medical device extending through the passage and engages the medical device to impart oscillatory motion thereto as the inertial driver is moved by the driving power. The imparted oscillatory motion travels along the medical device as a waveguide to deliver the oscillatory motion to tissue receiving the medical procedure to perform the MRE procedure. | 10-11-2012 |
20120268128 | Method for Principal Frequency Magnetic Resonance Elastography Inversion - A method for calculating a mechanical property of a material using a magnetic resonance imaging (“MRI”) system is provided. The method is particularly robust to image data having low signal-to-noise ratio (“SNR”). An MRI system is used to acquire magnetic resonance elastography (“MRE”) data from a subject containing the material. Exemplary materials include lung tissue. Images are reconstructed from the MRE data and used to produce a wave image from which a spatial frequency spectrum is produced. A principal frequency of the spatial frequency spectrum is produced and used to calculate a mechanical property of the material. For example, shear stiffness may be calculated. | 10-25-2012 |
20120269415 | Method for Magnetic Resonance Elastography Using Transient Waveforms - A dynamic magnetic resonance elastography (“MRE”) method for quantifying liver stiffness using intrinsic transient waveforms imparted on the liver by the beating heart is provided. The method includes synchronizing motion-encoding gradients in an MRE pulse sequence to the subject's cardiac cycle. | 10-25-2012 |
20120271150 | Flexible Passive Acoustic Driver for Magnetic Resonance Elastography - A flexible passive acoustic driver for use in an acoustic driver system which applies an oscillating stress to a subject undergoing a magnetic resonance elastography (MRE) examination which includes receiving acoustic pressure waves from an active driver through a tube and imparts pressure waves to a subject of an imaging procedure. In one configuration, the passive driver includes a flexible bag that forms the walls of an acoustic cavity, and a structure filling material located inside the acoustic cavity provides support for the flexible bag. The flexible bag conforms to the shape of the subject and may be held in place by an elastic band. The passive driver can have an integrated or detachable non-active push-on compartment which is rigid or semi-flexible to improve the human-driver mechanical coupling and the driver energy efficiency of converting acoustic pressure to mechanical vibration applied to a subject. | 10-25-2012 |
20130131490 | System and Method for Determining The Presence of a Neurodegenerative Disease Using Magnetic Resonance Elastography - 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. | 05-23-2013 |
20140073906 | Passive Acoustic Driver for Magnetic Resonance Elastography - An acoustic driver system for use in applying an oscillating stress to a subject undergoing a magnetic resonance elastography (MRE) examination includes a flexible passive driver located in the bore of the magnet and in contact with the subject. A remotely located active driver is acoustically coupled to the passive driver and produces acoustic energy in response to an applied current. The passive driver produces shear waves in response to the acoustic energy and are directed into the body of the subject undergoing the MRE examination. | 03-13-2014 |
20140107467 | System And Method For Improved Efficiency In Magnetic Resonance Elastography - 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. | 04-17-2014 |
20140114177 | SYSTEM AND METHOD FOR MAGNETIC RESONANCE ELASTOGRAPHY OF THE BREAST - A system and method for performing magnetic resonance elastography (MRE] of a patient's breasts is provided. An MRE driver configured to be placed on the sternum of the patient is used to impart mechanical energy to the sternum, which in turn generates shear waves in at least one of the patient's breasts. Such a driver is amenable to use with standard breast radio frequency (RF] coils without the need for modification of the existing breast RF coil hardware. | 04-24-2014 |