Ovidiu Andronesi - Melrose MA, US Bruce Rosen - Lexington MA, US Peter Caravan - Cambridge MA, US Himanshu Bhat - Cambridge MA, US
International Classification:
G01R 33/36
US Classification:
324309, 324318
Abstract:
A system acquires MR imaging data of a portion of patient anatomy associated with proton spin lattice relaxation time in a rotating frame using an RF (Radio Frequency) signal generator configured to generate RF excitation pulses and a magnetic field gradient generator configured to generate anatomical volume select magnetic field gradients for phase encoding and readout RF data acquisition. The RF signal generator and the gradient generator are configured to provide a rotating frame preparation pulse sequence comprising at least one of, (a) a T1 spin lattice relaxation in a rotating frame (T1ρ) preparation pulse sequence of adiabatic pulses comprising modulated RF pulses and modulated magnetic field gradients for slice selection and (b) a T2 spin-spin relaxation in a rotating frame (T2ρ) preparation pulse sequence of adiabatic pulses comprising modulated RF pulses and modulated magnetic field gradients for slice selection
System For Accelerated Segmented Mr Image Data Acquisition
Himanshu Bhat - Cambridge MA, US Jonathan Rizzo Polimeni - Cambridge MA, US
International Classification:
G06T 11/00
US Classification:
382131
Abstract:
A system for accelerated segmented magnetic resonance (MR) image data acquisition includes an RF (Radio Frequency) signal generator and a magnetic field gradient generator. The RF signal generator generates RF excitation pulses in anatomy and enabling subsequent acquisition of associated RF echo data. The magnetic field gradient generator generates magnetic field gradients for anatomical volume selection, phase encoding, and readout RF data acquisition in a three dimensional (3D) anatomical volume. The RF signal generator and the magnetic field gradient generator acquire consecutive segments of k-space line data representative of an individual image slice in a gradient echo method by adaptively varying RF excitation pulse flip angle between acquisition of the consecutive segments.
Himanshu Bhat - Cambridge MA, US Andre Jan Willem Van Der Kouwe - Woburn MA, US Matthew Dylan Tisdall - Somerville MA, US Keith Aaron Heberlein - Charlestown MA, US
Assignee:
Siemens Medical Solutions USA, Inc. - Malvern PA
International Classification:
G01R 33/44
US Classification:
324307
Abstract:
A system determines motion correction data for use in diffusion MR imaging using an RF signal generator and magnetic field gradient generator which sequentially acquire in a single first direction through a volume, first and second slice sets individually comprising multiple individual diffusion image slices. The first set of slices and the second set of slices are spatially interleaved within the volume, by providing in acquiring the second slice set, a low flip angle RF pulse successively followed by a non-diffusion image data readout magnetic field gradient for acquisition of data representing a two dimensional (2D) non-diffusion image used for motion detection of the first slice set successively followed by, a first diffusion imaging RF pulse followed by a first diffusion imaging phase encoding magnetic field gradient for preparation for acquiring data representing a diffusion image slice of the second slice set.
Guiding Protocol Development For Magnetic Resonance Thermometry
A method for decomposing noise into white and spatially correlated components during MR thermometry imaging includes acquiring a series of MR images of an anatomical object and generating a series of temperature difference maps of the anatomical object. The method further includes receiving a selection of a region of interest (ROI) within the temperature difference map and estimating total noise variance values depicting total noise variance in the temperature difference map. Each total noise variance value is determined using a random sampling of a pre-determined number of voxels from the ROI. A white noise component and a spatially correlated noise component of the total noise variance providing a best fit to the total noise variance values for all of the random samplings are identified. The white noise component and the spatially correlated noise component are displayed on a user interface.
Simultaneous Multi-Slab Thermometry During Mr-Guided Thermal Therapy
A method for performing magnetic resonance-guided thermal therapy includes selecting a first set of sampling characteristics for acquiring a first set of slabs covering a first anatomical region of interest. Additionally, a second set of sampling characteristics is selected for acquiring a second set of slabs covering a second anatomical region of interest. This second set of sampling characteristics is distinct from the first set of sampling characteristics. An interleaved acquisition of the first set of slabs and the second set of slabs may then be performed using the first set of sampling characteristics and the second set of sampling characteristics.
Data Acquisition Acceleration In Magnetic Resonance Angiography Applications Using Magnetization-Prepared Simultaneous Multi-Slice Acquisition
- Erlangen, DE - Evanston IL, US Ioannis Koktzoglou - Des Plaines IL, US Himanshu Bhat - Newton MA, US
International Classification:
A61B 5/026 G01R 33/563 G01R 33/56
Abstract:
A method for producing an image representative of the vasculature of a subject using a MRI system includes the acquisition of a signal indicative of a subject' cardiac phase. During each heartbeat of the subject, image slices of a volume covering a region of interest (ROI) within the subject are acquired by applying a volume-selective venous suppression pulse to suppress (a) venous signal for an upper slice in the ROI; (b) venous signal for slices that are upstream for venous flow in the ROI; and (c) background signal from the upstream slices. Next, a slice-selective background suppression pulse is applied to suppress background signal of the upper slice. Following a quiescent time interval, a spectrally selective fat suppression pulse is applied to the entire volume to attenuate signal from background fat signal. Then, a simultaneous multi-slice acquisition of the upper slice and the upstream slices is performed.
Data Acquisition Acceleration In Magnetic Resonance Angiography Applications Using Magnetization-Prepared Simultaneous Multi-Slice Acquisition
A method for producing an image representative of the vasculature of a subject using a MRI system includes the acquisition of a signal indicative of a subject' cardiac phase. During each heartbeat of the subject, image slices of a volume covering a region of interest (ROI) within the subject are acquired by applying a volume-selective venous suppression pulse to suppress (a) venous signal for an upper slice in the ROI; (b) venous signal for slices that are upstream for venous flow in the ROI; and (c) background signal from the upstream slices. Next, a slice-selective background suppression pulse is applied to suppress background signal of the upper slice. Following a quiescent time interval, a spectrally selective fat suppression pulse is applied to the entire volume to attenuate signal from background fat signal. Then, a simultaneous multi-slice acquisition of the upper slice and the upstream slices is performed.
Shifted Pulses For Simultaneous Multi-Slice Imaging
- Erlangen, DE Himanshu Bhat - Newton MA, US Vibhas S. Deshpande - Austin TX, US
International Classification:
G01R 33/483 G01R 33/50 G01R 33/567 G01R 33/48
Abstract:
A computer-implemented method for performing multi-slice magnetic resonance imaging with comparable contrast between simultaneously excited slices includes applying a first pulse sequence to a volume of interest to acquire a first k-space dataset. This first pulse sequence comprises a plurality of single-band slice-selective pulses applied in a first predefined order. One or more additional pulse sequences are also applied to the volume of interest to acquire one or more additional k-space datasets. Each additional pulse sequence comprises the plurality of single-band slice-selective pulses applied in one or more additional predefined orders that are distinct from the first predefined order. One or more final images are reconstructed using the first k-space dataset and the one or more additional k-space datasets.
Siemens Healthcare
Director, Mri R and D Collaborations
Northwestern University 2006 - 2010
Research Assistant
Education:
Northwestern University 2003 - 2010
Doctorates, Doctor of Philosophy, Biomedical Engineering, Philosophy
University of Houston 2004 - 2006
Masters, Electrical Engineering
College of Engineering Pune 2000 - 2004
Bachelors, Electrical Engineering
College of Technology, G.b.p.u.a&T, Pantnagar 1996 - 2000
Skills:
Mri Research Biomedical Engineering Digital Imaging R&D Medical Devices Signal Processing Image Processing Validation Medical Imaging Physics Matlab Clinical Research Science