LEON AXEL
Medical Practice in Philadelphia, PA

2004007, Apr 15, 2004

Jul 24, 2003

10/627367

Leon Axel - Philadelphia PA, US

New York University

A61B005/04

600/509000

The invention relates to methods and systems for detecting QRS complex in a ECG of a patient undergoing magnetic resonance imaging and automating data acquisition in the magnetic resonance imaging machine upon detection. The method and system operates by recording an ECG signal sample from the patient, receiving a real-time ECG signal from a patient undergoing MRI and correlating the real-time ECG signal with a previously determined QRS complex template derived from the ECG signal received from the patient before undergoing MRI.

5054489, Oct 8, 1991

Oct 6, 1988

7/254454

Leon Axel - Philadelphia PA
Lawrence Dougherty - Wenonah NJ

The Trustees of the University of Pennsylvania - Philadelphia PA

A61B 5055

128653A

A novel magnetic resonance imaging technique provides direct imaging of motion by spatially modulating the degree of magnetization prior to imaging. The pre-imaging pulse sequence consists of an RF pulse to produce transverse magnetization, a magnetic field gradient pulse to "wrap" the phase along the direction of the gradient and a second RF pulse to mix the modulated transverse magnetization with the longitudinal magnetization. The resulting images show periodic stripes due to the modulation. Motion between the time of striping and image formation is directly demonstrated as a corresponding displacement of the stripes. Applications include studies of heart wall motion and distinguishing slowly moving blood from thrombus.

5111820, May 12, 1992

Nov 2, 1990

7/608209

Leon Axel - Philadelphia PA
Lawrence Dougherty - Wenonah NJ

The Trustees of the University of Pennsylvania - Philadelphia PA

A61B 5055

128653A

Spatial Modulation of Magnetization (SPAMM) with two sets of tagging planes orthogonal to the image plane is used in accordance with known techniques to image two-dimensional heart wall motion with MRI. However, such techniques are modified in accordance with the invention to permit direct assessment of three-dimensional heart wall motion from two-dimensional images using a three-dimensional SPAMM technique and a phase shift SPAMM technique. The three-dimensional SPAMM technique uses a third set of tagging planes oblique to the image plane to separate within-plane motion from through-plane motion. In accordance with the 3-dimensional SPAMM technique, the displacement of the oblique magnetization lines relative to the displacement of the spatial modulation pattern in the imaging plane during a preimaging time interval is indicative of the displacement of a body portion such as a patient's heart wall through the imaging plane during the preimaging time interval. Preferably, the oblique angle is 45. degree. so that the amount of stripe displacement is equal to the amount of through-plane-motion.

4618827, Oct 21, 1986

Sep 10, 1984

6/648567

Rowland W. Redington - Schenectady NY
Leon Axel - Philadelphia PA

General Electric Company - Schenectady NY

G01R 3320

324309

An improved method for providing a high-spatial-resolution NMR image, having resolved artifact-free NMR images of chemically-shifted nuclei, includes: forming a pair of NMR images each having imaging components of each of the chemically-shifted nuclei due to projections in one of a pair of opposite directions along a common line; mirroring the imaging components of one of the NMR images about a line orthogonal to the common line; registering and combining the mirrored image and the other image to eliminate a first one of the components and thus produce a composite image containing only the other component and a negative of the other component offset by twice the chemical shift; and forming a resolved image of the other component by processing the composite image to eliminate the offset negative image. The resolved image may then be combined with one or more of the NMR images to produce a resolved image of the first component. The method requires only 2N projections to form the two N-by-N NMR images.

5217016, Jun 8, 1993

Apr 15, 1991

7/685915

Leon Axel - Philadelphia PA
Meir Shinnar - Bala Cynwyd PA

The trustees of the University of Pennsylvania - Philadelphia PA

A61B 5055

1286532

A technique for generating "optimal" radio frequency pulses for use in creating SPAMM imaging stripes. The MR imaging operator is given an opportunity to select the desired stripe parameters for the SPAMM imaging stripe so that the resulting SPAMM imaging stripe will have the desired narrowness, sharpness, flatness and the like. These parameters are then used by an optimal pulse generating system of the invention to generate the input radio frequency pulse sequence which will produce the desired stripes. This technique allows a large family of pulse sequences with fairly similar performance to be generated by simply adjusting the relative weightings of criteria such as the narrowness, sharpness, flatness and the like for the SPAMM stripes.

7345480, Mar 18, 2008

Nov 15, 2004

10/579506

Vinay Manjunath Pai - New York NY, US
Leon Axel - Philadelphia PA, US

New York University - New York NY

G01V 3/00

324309, 324307

A method, system, and software arrangement for automatically prescribing long-axis magnetic resonance imaging (“MRI”) slices of a target are provided. An MRI image is captured along a short-axis slice of the target. Vectorial components, including slice selection, phase-encoding, and frequency encoding vectors, are extracted from the short-axis slice. Vectorial components are established for a long-axis slice using the vectorial components of the short-axis slice, by transposing the slice-selection and frequency-encoding vectors. A plurality of long-axis slice planes are defined in a manner positioned relative to the long axis slice, rotating about a long axis in a direction of a long-axis frequency encoding vector. In one exemplary embodiment, frequency and phase shifts are established for each of the long-axis slices, for use in RF transmitting and receiving.

7215123, May 8, 2007

May 4, 2005

11/122556

Leon Axel - Philadelphia PA, US

New York University - New York NY

G01V 3/00

324318, 324320

A method and system for homogenizing a main magnetic field of a magnetic resonance imaging (“MRI”) system includes obtaining a main magnetic field distribution generated by the MRI system, obtaining at least one shim magnetic field distribution generated by at least one shim coil of the MRI system, and determining a corresponding shim current based on a relationship between the main magnetic field distribution and the at least one shim magnetic field distribution.

7468644, Dec 23, 2008

Nov 5, 2004

10/578540

Leon Axel - Philadelphia PA, US

New York University - New York NY

H01P 7/00

333219

A gradient coil arrangement generates magnetic field gradients across the main magnetic field of a magnetic resonance imaging system and includes a first conductive member, and a second conductive member electrically coupled to the first conductive member, wherein the second conductive member forms a segment that has an approximate shape of an arc when viewed along a direction of extension of the first conductive member.