Apparatus and techniques are described herein for nuclear magnetic resonance (MR) projection imaging. Such projection imaging may be used for generating four-dimensional (4D) imaging information representative of a physiologic cycle of a subject, such as including generating two or more two-dimensional (2D) images, the 2D images comprising projection images representative of different projection angles, and the 2D images generated using imaging information obtained via nuclear magnetic resonance (MR) imaging, assigning the particular 2D images to bins at least in part using information indicative of temporal positions within the physiologic cycle corresponding to the particular 2D images, constructing three-dimensional (3D) images using the binned 2D images, and constructing the 4D imaging information, comprising aggregating the 3D images.

In a magnetic resonance method and apparatus for determining a characteristic of an organ, a magnetic resonance sequence is executed in order to acquire temporally resolved magnetic resonance data pertaining to the organ. The magnetic resonance sequence includes at least one tagging module, which generates a sub-visual tag of the magnetic resonance data. The characteristic of the organ is determined in a processor using the sub-visual tag.

A method for generating a movement signal of a body part, of which at least a portion is undergoing a cardiac movement, includes providing a pilot tone signal acquired from the body part by a magnetic resonance receiver coil arrangement. A demixing matrix is calculated from a calibration portion of the Pilot Tone signal using an independent component analysis algorithm. The independent component corresponding to the cardiac movement is selected. The demixing matrix is applied to further portions of the pilot tone signal to obtain a movement signal representing the cardiac movement. An, adaptive stochastic, or model-based filter is applied to the signal representing the cardiac movement, to obtain a filtered movement signal.

Systems and methods are provided for performing automated reconstruction of a dynamic MRI dataset that is acquired without a fixed temporal resolution. On one or more image quality metrics (IQMs) are obtained by processing a subset of the acquired dataset. In one example implementation, at each stage of an iterative process, one or more IQMs of the image subset is computed, and the parameters controlling the reconstruction and/or the strategy for data combination are adjusted to provide an improved or optimal image reconstruction. Once the IQM of the image subset satisfies acceptance criteria based on an estimate of the overall temporal fidelity of the reconstruction, the full reconstruction can be performed, and the estimate of the overall temporal fidelity can be reported based on the IQM at the final iteration.

A magnetic resonance imaging method according to an embodiment includes performing a balanced SSFP sequence, repeatedly applies an excitation RF pulse to a subject at intervals of a repetition time and applies gradient magnetic field pulses balanced such that a time integral becomes zero within each interval of the repetition time, while further applying a spin labeling gradient magnetic field for generating one or more continuous spin labels within each interval of the repetition time.

An image reconstruction apparatus according to an embodiment includes a processing circuitry configured to reconstruct at least one image from a plurality of pieces of k-space data acquired in a time direction. The processing circuitry performs image estimation calculation that reconstructs estimated images sharing the k-space data in the time direction, and adaptation calculation that adapts the estimated images to prior knowledge in the time direction.

In a method and apparatus for acquiring and reconstructing a four-dimensional dynamic magnetic resonance (MR) image data record, MR data are continuously acquired by radial scanning of an examination region along radial k-space lines, and a dynamic region of the examination region, in which said dynamic procedure is relevant, is determined, as well as a non-dynamic region, which is not relevant to the dynamic procedure. Static image data are reconstructed from all of the acquired MR data, and image data therein originating from the non-dynamic region are marked and are then not used for reconstructing a dynamic image data record for the dynamic region.

An imaging method may include obtaining imaging data associated with a region of interest (ROI) of an object. The imaging data may correspond to a plurality of time-series images of the ROI. The imaging method may also include determining, based on the imaging data, a data set including a spatial basis and one or more temporal bases. The spatial basis may include spatial information of the imaging data. The one or more temporal bases may include temporal information of the imaging data. The imaging method may also include storing, in a storage medium, the spatial basis and the one or more temporal bases.

Techniques exist for measuring local blood velocity of flow rate waveforms in, for example, mammalian vascular segments. A method and system for deriving information on disease in vascular segments, for example mean pressure, drop in mean pressure and/or hydraulic resistance, from such measured waveforms is described. The waveforms can, for example, be measured non-invasively using Doppler ultrasound or magnetic resonance techniques. Form factors (Vff, Pff) for the velocity waveform and the central arterial pressure are determined. Stenosis may be detected by detecting changes e.g in Vff/Pff.

The invention relates to a method of MR imaging of an object. It is an object of the invention to provide a multi-gradient echo imaging technique with increased acquisition speed and intrinsic suppression of artefacts from Bo inhomogeneities, T.sub.2* decay, chemical shift, motion, and/or flow, in particular in combination with radial or spiral k-space trajectories. The method of the invention comprises the steps of: —subjecting the object (10) to an imaging sequence comprising RF excitation pulses and switched magnetic field gradients, wherein multiple echo signals are generated at different echo times after each RF excitation pulse, —acquiring the echo signal data along radial or spiral k-space trajectories, wherefore the imaging sequence comprises magnetic field gradient blips in the x-/y- and/or z-directions; —separating signal contributions from water and fat to the echo signals and estimating a B.sub.0 map and/or an apparent transverse relaxation time map (T.sub.2* map) using a Dixon algorithm; and —synthesizing an image of a specified contrast from the echo signal data, the Bo map and/or the T.sub.2* map. Moreover, the invention relates to a MR device (1) and to a computer program for a MR device (1).