MR imaging comprising the steps of: subjecting an object (10) to an imaging sequence of RF pulses and switched magnetic field gradients (GS, GP, GM), which imaging sequence is a steady state sequence comprising a plurality of repeatedly applied acquisition blocks (21), wherein each acquisition block (21) comprises two units (22, 23) in immediate succession, namely: i) a first unit (22) starting with an excitation RF pulse radiated toward the object (10), with the duration of the first unit being an integer multiple of a given time interval T, and ii) a second unit (23) starting with a refocusing RF pulse radiated toward the object (10) and comprising a readout magnetic field gradient (GM) and a phase encoding magnetic field gradient (GP), with the duration of the second unit (23) being an integer multiple of the time interval T, acquiring one or more phase-encoded spin echo signals (31, 32) in a sequence of acquisition blocks (21), and reconstructing one or more MR images from the acquired spin echo signals (31, 32). Moreover, the invention relates to a MR device (1) and to a computer program for a MR device (1).

Provided herein are systems and methods for generating fetal cardiac magnetic resonance (MR) images of a living fetus, within a uterus of a parent of the fetus, by imaging the fetus within the uterus using a magnetic resonance imaging (MRI) system. Also provided herein are methods for deriving information indicative of fetal cardiac cycles from MR data obtained by an MRI system while imaging the fetus, the MR data including MR data for the center of k-space. The derived information may be used to differentiate the fetal cardiac cycles from other sources of noise in the MR data such as the parental cardiac cycles.

A magnetic resonance imaging (MRI) system and methods are provided for producing images of a subject. In some aspects, a method includes identifying a point in the cardiac cycle, performing an inversion recovery (IR) pulse at a selected time point from the pre-determined point, and sampling a k-space segment at an inversion time from the IR pulse that is substantially coincident with the pre-determined point. The method also includes repeating the IR pulse and k-space sampling for multiple inversion times, and multiple segments of k-space, in an interleaved manner, to generate datasets having T1-weighted contrasts determined by their respective inversion times. The method further includes reconstructing three-dimensional (3D) spatially-aligned images using the datasets, and generating a T1 recovery map by combining the 3D images. In some aspects, a prospective/retrospective scheme may be used to obtain data fully sampled in the center of k-space and randomly undersampled in the outer regions.

A magnetic resonance method and system are provided for projection MR imaging of vascular structures within a subject, with scan times that are shorter than those needed for conventional techniques. Image acquisition sequences are synchronized with heartbeat cycles of the subject, and are configured to generate image data having a reduced spatial resolution in the projection direction perpendicular to a preselected projection plane. A reduction factor F quantifies this reduced resolution, such that the number of data acquisition sequences provided within each heartbeat cycle is F times as many as a comparable imaging protocol that generates full-resolution data. The total scan time can be reduced by a factor of F with negligible degradation in the projection image quality.

The invention relates to a method of MR imaging of an object (10) placed in an examination volume of a MR device (1). It is an object of the invention to enable MR signal acquisition in a single scan providing the necessary information for electric properties imaging (EPT), namely a phase map as well as tissue boundaries. The method of the invention comprises the following steps: —subjecting the object (10) to a multi echo steady state imaging sequence or a fast spectroscopic imaging sequence comprising RF pulses and switched magnetic field gradients, wherein two or more echo signals are generated after each RF excitation; —acquiring the echo signals; —deriving a magnitude image and a phase map from the acquired echo signals, which phase map represents the spatial RF field distribution induced by the RF pulses in the object (10); and —reconstructing an electric conductivity map from the magnitude image and from the phase map, wherein tissue boundaries are derived from at least the magnitude image. Moreover, the invention relates to a MR device for carrying out this method as well as to a computer program to be run on a MR device.

Systems and methods providing enhancements to quantitative imaging systems and techniques are described herein. In one aspect, a system for tissue quantification in magnetic resonance fingerprinting (MRF) comprises a feature extraction module operable to convert pixel input high-dimensional signal evolution in to a low-dimensional feature map. The system also comprises a spatially constrained quantification module operable to capture spatial information from the low-dimensional feature map and generate an estimated tissue property map.

An MRI device for executing an imaging operation at least three times or more with a different combination of at least a repetition time and a flip angle in the same imaging sequence, includes: a receiving unit which receives information specifying an imaging target and a constraint condition relating to an imaging time or quantitative value accuracy; and a scan parameter set generation unit which calculates at least three or more scan parameter sets having a different combination of at least the repetition time and the flip angle on the basis of the constraint condition. The MRI device uses three or more scan parameter sets generated by the optimal scan parameter set generation unit and calculates quantitative values (T1, T2,and the like) of the imaging target from a plurality of images obtained by the imaging operation.

In magnetic resonance imaging using a measurement sequence of the “free precession of transverse magnetization in the steady state”-type i.e., an SSFP measurement sequence, during the SSFP measurement sequence, the implementation of a preparation sequence takes place to reduce a signal contribution of the transverse magnetization in an outer region surrounding a measurement region in the MR imaging. The implementation of the preparation sequence includes the radiation of a multidimensional, spatially selective RF pulse that acts in a spatially selective manner on the transverse magnetization in the outer region. Saturation of the transverse magnetization and/or dephasing of the transverse magnetization in the outer region can be achieved by the multidimensional, spatially selective RF pulse.

The estimation accuracy of a magnetic susceptibility value of tissue is improved by computing an edge image which represents the edge of the tissue on a magnetic susceptibility distribution and to reduce background noise without lowering the magnetic susceptibility value of the tissue. The present invention computes an absolute value image and a phase image from a complex image obtained by MRI, from the phase image, computes a low frequency region magnetic susceptibility image in which background noise is greater than a desired value, computes an edge information magnetic susceptibility image and computes a high frequency region magnetic susceptibility image, computes an edge mask from the edge information magnetic susceptibility image, smooths a magic angle region from the edge mask and the low frequency region magnetic susceptibility image and finally smooths a high frequency region using the high frequency region magnetic susceptibility image.

Systems and methods for motion sensitized and motion suppressed quantitative imaging of a subject are provided as a train of interlaced radio frequency (RF) and magnetic field gradient pulses. Non-selective Delay Alternating with Nutation for Tailored Excitation (DANTE) pulse trains may be used in combination with gradient pulses and short repetition times as motion-sensitive preparation modules. In one or more embodiments, the systems and methods may use a train of low flip angle radio frequency (RF) pulses in combination with a blipped field gradient pulse between each RF pulse, repeated regularly. While the longitudinal magnetization of static tissue is mostly preserved, moving spins are largely (or fully) suppressed since they fail to establish transverse steady state due to a spoiling effect caused by flow along the applied gradient. The present systems and methods can be incorporated into any existing imaging readout for applications in vessel wall imaging, angiography, high resolution structural MRI, and also functional MRI.