Vanderbilt University

Medtronic Navigation, Inc.

General Electric Company

The General Hospital Corporation

Case Western Reserve University

Vanberbilt University

William Allyn Grissom

Andrew Wald

Rebecca L Vincelette

Christine R Drown

Yuval Zur

Charles F Caskey

Xinqiang Yan

Mark A Griswold

Kawin Setsompop

Jonathan R Polimeni

John C Gore

Thomas Witzel

Pekka Tapani Sipilä

Laura Irene Sacolick

Mark Does

Rolf Feodor Schulte

Avery J L Berman

Zhipeng Cao

A system and method to analyze image data. The image data may be used to assist in determine the presence of a feature in the image. The feature may include a bubble.

Method and apparatus for magnetic resonance imaging thermometry

A system and method of magnetic particle imaging (MPI) are disclosed. The system and method use ultrasound to drive magnetic particles (such as nanoparticles) through a magnetic field gradient to generate a signal and map the magnetic particles' distribution or concentration.

Magnetic particle imaging using an ultrasonic driving field

A system for transcranial magnetic resonance (MR)-guided focused ultrasound and method of using transcranial MR-guided focused ultrasound are disclosed. The system includes a transcranial ultrasound transducer configured to apply ultrasound radiation to a patient's head. The system also includes an antenna that reflects radio frequency (RF) waves. The antenna is configured to be positioned between the transducer and the patient's head. The antenna and at least a portion of the patient's head are surrounded by a fluid. Embodiments foster improved MR image quality scans of the patient's head when the transducer is filled with the fluid.

Passive wire reflectors for improved image quality in MR-guided focused ultrasound

Described here are systems and methods for producing images with a magnetic resonance imaging ('MRI') system using a high-resolution, motion-robust, artifact-free segmented echo planar imaging (“EPI”) technique. In particular, a fast low angle excitation echo planar imaging technique (“FLEET”) using variable flip angle (“VFA”) radio frequency (“RF”) excitation pulses that are recursively designed to have a flat magnitude and phase profile across a slice for a range of different flip angles by accounting for longitudinal magnetization remaining after each preceding RF pulse is applied.

Multi-shot echo planar imaging using reordered segments and recursive radio frequency pulse design giving matched slice profiles across segments

The present application provides a system and method for using a nuclear magnetic resonance (NMR) system. The method includes performing a pulse sequence using the NMR system that spatially encodes NMR signal evolutions to be acquired from a subject using an aggregated radio-frequency (B1) field incoherence and resolving the NMR signal evolutions acquired from the subject using at least one of a dictionary of known magnetic resonance fingerprinting (MRF) signal evolutions to determine matches in the NMR signal evolutions to the known MRF signal evolutions or an optimization process. The method also includes generating at least two spatially-resolved measurements indicating quantitative tissue parameters of the subject in at least two locations.

System and method for B1-selective spatial encoding using magnetic resonance

A self-decoupled RF coil and method for adjusting the same is disclosed. The RF coil is an array of elements including at least one loop. Electromagnetic coupling between elements in the array causes an induced current in the at least one loop. The induced current has two modes. A reactance inserted in the at least one loop balances the two modes. The balanced current modes cancel. This cancelation results in self-decoupling of at the least one loop from the other elements in the RF coil array.

Self-decoupled RF coil array for MRI

Systems and methods for performing MRI include using a RF gradient field for spatial encoding. In particular implementations, |B|-selective pulses designed using the Shinnar-Le Roux algorithm can be provided as the excitation pulse for the RF gradient field. Further, frequency encoding for the RF gradient field can be based on the Bloch-Siegert (BS) shift. Together, these techniques can be used to support MRI based on RF gradient encoding instead of the conventional Bo encoding.

MRI using RF gradients for spatial encoding

A system and method for MR imaging is disclosed. The method causes an RF coil assembly and plurality of gradient coils to apply a fast spin echo (FSE) pulse sequence comprising a preparation segment and a plurality of refocusing segments. The FSE pulse sequence generates a pair of echoes is generated in each of the plurality of refocusing segments that comprises a first echo generated by magnetization pathways having an even number of phase inversions and a second echo generated by magnetization pathways having an even number of phase inversions. MR signals are acquired from the first echo and the second echo and an image of at least a portion of a subject of interest is reconstructed from the acquired MR signals.

System and method for focusing of high intensity focused ultrasound based on magnetic resonance&#x2014;acoustic radiation force imaging feedback

A system and method for focusing ultrasound into a target tissue is disclosed. The method calculates a pressure field for an array of transducer elements to generate an unaberrated pressure field matrix and causes the transducer elements to apply focused ultrasound to generate a respective aberrated pressure field at a focus location in a target tissue and surrounding volume. MR-ARFI images are acquired of the focus location and surrounding volume, a magnitude of the aberrated pressure field is measured that is generated by the applied focused ultrasound at respective focus locations in the target tissue and surrounding volume based on the MR-ARFI images, an aberration for the transducer elements is determined from the pressure field matrix and the MR-ARFI images of the focus location and the surrounding volume using a magnitude least-squares method, and a corrective phase/amplitude adjustment is applied to the transducer elements based on the determined aberrations.

A method of B1 field mapping relating to Magnetic resonance imaging (MRI) is given. In the method, RF and gradients are applied to excite and select a linear projection through a volume of interest; a radio frequency pulse sequence is transmitted to impart B1 dependent phase to the linear projection, following which a one dimensional spatial encoding signal is acquired along the linear projection; Subsequently a B1 field map based on the one dimensional spatial encoding signal is reconstructed.

Growing community of inventors

Nashville, TN, United States of America

William Allyn Grissom