Johns Hopkins University

The United States of America, As Represented by the Secretary, Department of Health and Human Services

The United States of America As Represented by the Department of Health

Matthias Stuber

Reza Nezafat

Jerry L Prince

Wesley David Gilson

Nael Fakhry Osman

Ronald Ouwerkerk

Dara L Kraitchman

Khaled Zakarya Abd-Elmoniem

Elliot R McVeigh

J Andrew Derbyshire

Featured are methods for magnetic resonance imaging of a volume, such a volume having susceptibility-generating objects or interfaces having susceptibility mismatches therein. Such a method includes selectively visualizing one of susceptibility-generating objects or interfaces having susceptibility mismatches as hyperintense signals, where such visualizing includes controlling variable imaging parameters so as to control a geometric extent of a signal enhancing effect, m more particular aspects of the present invention, such selectively visualizing includes attenuating or essentially suppressing signals from fat and/or water, namely on-resonant water protons, so as to thereby enhance a signal(s) associated with magnetic susceptibility gradient(s). Also featured are MRI systems, apparatuses and/or applications programs for execution on a computer system controlling the MRI data acquisition process embodying such methods.

Method for magnetic resonance imaging using inversion recovery with on-resonant water suppression including MRI systems and software embodying same

Three-dimensional MR motion estimation on a single image plane based on tagged MRI and HARP processing. Tagged magnetic resonance imaging technique encodes and automatically tracks displacement of spatially modulated object in three dimensions, encoding both in plane and through-plane motion in a single image plane without affecting acquisition speed. Post-processing unravels encoding in order to directly track 3-D displacement of points within the image plane throughout image sequence. The invention is particularly suited to use on a heart for tracking and determining myocardial displacement. In one embodiment, an MR pulse sequence extends a slice following complementary spatial modulation of magnetization (CSPAMM) pulse sequence with two small z-encoding gradients immediately before the readouts in successive CSPAMM acquisitions, thereby adding a through-plane encoding from which through-plane motion can be computed from acquired images. HARP processing is used to determine in-plane motion, after which through-plane position can be determined using phase encodings. Use of balanced encodings and horizontal and vertical tags permits cancellation of systematic phase artifacts present in CSPAMM acquisitions.

Three dimensional magnetic resonance motion estimation on a single image plane

Adiabatic pulses that define an amplitude modulation and a frequency modulation are applied in a sequence of pulses to obtain a Tweighted magnetic resonance image. Such an adiabatic Tprep sequence typically includes a first 90&#xb0; pulse, an even number of adiabatic pulses, and a second 90&#xb0; pulse. Adiabatic pulses can be selected based on function pairs, or can be defined numerically. A magnetic resonance imaging (MRI) system includes a library of adiabatic pulse waveforms, and is configured to select a waveform and apply an RF magnetic field based on the selected pulse waveform.

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A Tpreparation sequence uses a segmented BIR-4 adiabatic pulse with two substantially equal delays and is insensitive to Bfield variations and can simultaneously suppress fat signals with low specific absorption rate (SAR). An adiabatic reverse half passage pulse is applied followed by a predetermined delay. An adiabatic full passage pulse is applied followed by a substantially equal delay, followed by an adiabatic half passage pulse. Fat signal suppression is achieved by increasing or decreasing either the first delay or the second delay.

Method for spectrally selective B1 insensitive T2 preparation contrast enhancement for high field magnetic resonance imaging

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Ellicott City, MD, United States of America

Matthias Stuber