Duke University

Siemens Healthcare Gmbh

Siemens Healthineers Ag

David C Wendell

Raymond J Kim

Wolfgang Gerhard Rehwald

Enn-Ling Chen

Elizabeth R Jenista

A method for reordering a segmented MRI pulse sequence includes synchronizing to a physiologic signal of a heart or vessel, to a respiratory signal, or to an external trigger source, and acquiring a plurality of data collecting segments as a contiguous block in a phase encoding direction such that lines of the plurality of data collecting segments are alternately acquired in a forward direction and a reverse direction for each consecutive data collecting segment.

Combined acquisition and reordering scheme for reconstructing images with reduced motion artifacts

A method for correcting image inhomogeneity includes acquiring a non-normalized image and a reference image using receiver coils. A high-signal mask and a low-signal mask are created. Each pixel in the high-signal mask is set to a predetermined integer value if the reference image pixel at the same specific location has a value above a threshold value. Each pixel in the low-signal mask is set to the predetermined integer value if the reference image pixel at the same specific location has a value below or equal to the threshold value. A coil normalization map is created by smoothing the reference image with filters. Then, an iterative procedure is performed to update the coil normalization map using the high-signal mask and the low-signal mask. Following the iterative procedure, the non-normalized image is divided by the current coil normalization map to yield a normalized image.

Magnetic resonance imaging coil normalization by using a reference image

A magnetic resonance imaging system and method are provided for improved phase-sensitive magnetic resonance imaging of tissues affected by cardiovascular pulsatile motion. A magnetically-prepared image dataset and corresponding reference image dataset (for phase sensitivity) are obtained within the duration of a single cardiac cycle. The paired datasets can be single-shot or segmented datasets and a navigator sequence can optionally be provided with each paired dataset. The system and method take advantage of the shape symmetry of the cardiac cycle to acquire the paired dataset in a shorter time interval, thereby reducing misregistration artifacts. The magnetic preparation can include inversion recovery pulses, FIDDLE sequences, other magnetic preparation sequences, or combinations thereof. The reference dataset can be acquired at a lower resolution than the corresponding magnetically-prepared dataset without compromising image quality.

Systems and methods for phase-sensitive inversion recovery MR imaging with reduced sensitivity to cardiac motion

Magnetic resonance imaging (MRI) systems and methods using adiabatic tip-down and matched adiabatic flip-back pulses are disclosed. According to an aspect, a system includes a signal generator configured to generate a pulse sequence for on-resonance magnetization transfer preparation. The pulse sequence includes an adiabatic tip-down pulse and a matched adiabatic flip-back pulse for separating spins in a mobile spin pool from spins in a bound spin pool of an anatomical region of interest for imaging. The system includes radio frequency (RF) coils configured to transmit RF pulses in response to the pulse sequence and to acquire RF data in response to transmission of the RF pulses. Further, the system includes a processing system configured to process the RF data to provide a display image indicating different tissue types with discrimination.

Magnetic resonance imaging (MRI) systems and methods using adiabatic tip-down and matched adiabatic flip-back pulses

Magnetic resonance imaging (MRI) systems and methods for determining and adjusting TI using single-line acquisition and automatic compartment detection. A method includes positioning a readout line of the MRI scanner through a compartment of interest of a region of interest in a subject. The method includes inverting magnetization within the readout line by playing an inversion pulse; and reading out data along the readout line after play of the inversion pulse. The method also includes determining a T1 value for each pixel along the readout line; determining the pixels that belong to first and second portions within the compartment of interest; determining a T1 value of each of the first and second portions by averaging the pixels within each portion; and determining an inversion time based on the determined T1 values such that the compartment of interest has a desired magnetization in an image to be acquired.

Magnetic resonance imaging (MRI) systems and methods for determining and adjusting inversion time (TI) using single-line acquisition and automatic compartment detection

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Durham, NC, United States of America

David C Wendell