Abstract: A magnetic resonance (MR) apparatus and method for controlling a generation of an imaging sequence for imaging a subject. The method includes generating an MR tracking sequence for tracking a position of an MR active device located in the subject; obtaining MR signals detected by the MR active device as a result of the generated tracking sequence; processing the obtained MR signals to determine the position of the MR active device; determining whether a trigger condition is satisfied by comparing the determined position of the MR active device to a predetermined trigger position; and generating the imaging sequence if the trigger condition is satisfied, wherein if the trigger condition is not satisfied, the imaging sequence is not generated.

Abstract: MRI based molecular imaging is strongly supported by the accurate quantification of contrast agents. According to an exemplary embodiment of the present invention, contrast agent is applied on the basis of a multiple injection application scheme, during which changes in relaxation rate are determined. This may provide for an accurate determination of rumor vascularity via MRI relaxometry.

Abstract: A fiducial marker assembly (30) is tracked using a magnetic resonance scanner (10). At the tracked position of the fiducial marker assembly, local B0 magnetic field inhomogeneity is measured. A warning is issued if the measured local B0 magnetic field inhomogeneity satisfies a warning criterion. A noise figure of merit of the tracking is also determined, and the warning is also issued if the noise figure of merit satisfies a noise-based warning criterion.

Abstract: The present invention provides a method MRI imaging. By applying a time modulation to the contrast enhancement of an MRI contrast agent, the method according to the invention leads to images with improved signal-to-noise ratio in the contrast-enhanced areas, strongly suppressed unwanted signal in the unenhanced areas, and reduced artefacts, such as motion artefacts.

Abstract: MRI based molecular imaging is strongly supported by the accurate quantification of contrast agents. According to an exemplary embodiment of the present invention, contrast agent is applied on the basis of a multiple injection application scheme, during which changes in relaxation rate are determined. This may provide for an accurate determination of rumor vascularity via MRI relaxometry.

Abstract: MRI based molecular imaging is strongly supported by the accurate quantification of contrast agents. According to an exemplary embodiment of the present invention, contrast agent is applied on the basis of a multiple injection application scheme, during which changes in relaxation rate are determined. This may provide for an accurate determination of tumor vascularity via MRI relaxometry.

Abstract: MRI device arranged to a) generate a series of MR echo signals from a nuclear spin series having two or more spectral lines by subjecting at least part of a body (7) to an MR imaging pulse sequence using multiple time-encoding echo time values, b) acquire the MR echo signals for reconstructing a series of time-encoded MR images therefrom, each time-encoded MR image being associated with one of the time-encoding echo time values, c) transform the series of time-encoded MR images into a series of spectral domain MR images on a pixel-by-pixel or voxel-by-voxel basis, d) and superimpose the MR images for obtaining a final image the device being further arranged to apply a time-encoding scheme in step a) such that each spectral line of the nuclear spin species is uniquely mapped to one MR image from the series of spectral domain MR images.

Abstract: MRI device arranged to a) generate a series of MR echo signals from a nuclear spin series having two or more spectral lines by subjecting at least part of a body (7) to an MR imaging pulse sequence using multiple time-encoding echo time values, b) acquire the MR echo signals for reconstructing a series of time-encoded MR images therefrom, each time-encoded MR image being associated with one of the time-encoding echo time values, c) transform the series of time-encoded MR images into a series of spectral domain MR images on a pixel-by-pixel or voxel-by-voxel basis, d) and superimpose the MR images for obtaining a final image the device being further arranged to apply a time-encoding scheme in step a) such that each spectral line of the nuclear spin species is uniquely mapped to one MR image from the series of spectral domain MR images.

Abstract: The invention relates to a device for magnetic resonance imaging of a body (7). The device (1) comprises means (2) for establishing a substantially homogeneous main magnetic field in the examination volume, means (3, 4, 5) for generating switched magnetic field gradients superimposed upon the main magnetic field, means (6) for radiating RF pulses towards the body (7), control means (12) for controlling the generation of the magnetic field gradients and the RF pulses, means (10) for receiving and sampling magnetic resonance signals, and reconstruction means (14) for forming MR images from the signal samples.

Abstract: A medical imaging system (2) excites multiple nuclei through a single RF amplifier (24). The medical imaging system (2) includes a magnet (10) that generates a main magnetic field (Bo) in an examination region. A gradient coil (14) superimposes magnetic field gradients (G) on the main magnetic field Bo. At least one transmitter (28) generates multi-nuclei excitation pulses associated with at least two different isotopes and two different frequency spectra. The single amplifier (24) sends the multi-nuclei excitation pulses to a RF coil (18, 20) for application to the examination region.

Abstract: The invention relates to an MR method for spatially resolved determination of relaxation parameters in an examination zone, comprising the steps: a. acquisition, by means of a first sequence, of MR data sets for a plurality of MR images having different echo times, b. acquisition, by means of a second sequence, of at least one further MR data set for at least one further MR image having an enhanced spatial resolution and reduced time resolution in comparison with the MR images of the first sequence, c. generation of MR combination images using an MR data set derived from the first sequence for a portion within the k-space and the MR data of a further MR data set acquired outside this portion by means of the second sequence, d. derivation of relaxation parameters from the MR combination images.

Abstract: The invention relates to an MR method for the quantitative determination of local relaxation time values in an examination volume. Firstly, a plurality of echo signals (1, 2, 3) with different echo time values (t1, t2, t3) are recorded in a phase-sensitive manner. From these echo signals (1, 2, 3), complex MR images (4, 5, 6) are then reconstructed for the different echo time values (t1, t2, t3). Next, local resonant frequency values (7) are calculated for each image point from the echo-time-dependent change in the phases of the complex image values, and then preliminary local magnetic field inhomogeneity values (8) are calculated from the local resonant frequency values (7). The invention proposes that the local relaxation time values (10) be determined from the echo-time-dependent change in the amplitudes of the image values and correction of the local relaxation time values (10) be carried out taking account of final local magnetic field inhomogeneity values.

Abstract: The invention relates to a device for magnetic resonance imaging of a body (7). The device (1) comprises means (2) for establishing a substantially homogeneous main magnetic field in the examination volume, means (3, 4, 5) for generating switched magnetic field gradients superimposed upon the main magnetic field, means (6) for radiating RF pulses towards the body (7), control means (12) for controlling the generation of the magnetic field gradients and the RF pulses, means (10) for receiving and sampling magnetic resonance signals, and reconstruction means (14) for forming MR images from the signal samples.

Abstract: MRI based molecular imaging is strongly supported by the accurate quantification of contrast agents. According to an exemplary embodiment of the present invention, contrast agent is applied on the basis of a multiple injection application scheme, during which changes in relaxation rate are determined. This may provide for an accurate determination of tumor vascularity via MRI relaxometry.

Abstract: The present disclosure is directed to a new technique for MR measurement of ultrashort T2* relaxation utilizing spin-echo acquisition. The ultrashort T2* relaxometry can be used for the quantification of highly concentrated iron labeled cells in cell trafficking and therapy. In an exemplary embodiment, a signal is induced by a low flip angle RF pulse. Following excitation pulse, a gradient readout is applied to form an echo. The time between the RF pulse and the center of the gradient readout is defined as TE. In tissues with highly concentrated iron labeled cells, T2* could be below 1 millisecond. Therefore, the signal can be decayed to a noise level with an echo time of a couple milliseconds. Because T2 is much longer in SPIO labeled cells, the signal acquired by spin echo is much bigger than that from the gradient echo, thus avoiding the negative effects associated with the massive signal loss in the image.

Abstract: MR based molecular imaging is used for the quantification of contrast agent concentrations. According to an exemplary embodiment of the present invention, a difference between R2 and R2* relaxation rates of a contrast agent is determined on the basis of data measured after contrast agent application. This may provide for an in vivo information relating to a compartmentalization or binding status of the contrast agent, and thus may improve the significance of the examination result.

Abstract: A medical imaging system (2) excites multiple nuclei through a single RF amplifier (24). The medical imaging system (2) includes a magnet (10) that generates a main magnetic field (Bo) in an examination region. A gradient coil (14) superimposes magnetic field gradients (G) on the main magnetic field Bo. At least one transmitter (28) generates multi-nuclei excitation pulses associated with at least two different isotopes and two different frequency spectra. The single amplifier (24) sends the multi-nuclei excitation pulses to a RF coil (18, 20) for application to the examination region.

Abstract: A method of magnetic resonance imaging is provided. The method includes the steps of applying a preparation pulse sequence to a subject (16) disposed in an examination region (14), acquiring k-space data related to a plurality of k-space trajectories through the center of k-space such as radial trajectories and reconstructing a first image form the k-space data wherein data within a region (210) around the center of k-space (205) of at least a first of the k-space trajectories is not used. Rather, data of only a limited number of views within said region is used for image reconstruction. Hence, image contrast is essentially determined by said limited number of views.

Abstract: An optical imaging apparatus (100) for examination of an object of interest (101), the optical imaging apparatus (100) comprising an optical radiation source (102) adapted to emit a primary optical radiation beam onto the object of interest (101), an optical radiation detector (106) adapted to detect a secondary optical radiation beam emitted by the object of interest (101) upon absorbing the primary optical radiation beam, a magnetic field generating element (107) adapted to generate an inhomogeneous magnetic field varying along an extension of the object of interest (101), and a determination unit (108) adapted to determine information concerning the object of interest (101) based on an analysis of the detected secondary optical radiation beam in combination with an analysis of the inhomogeneous magnetic field.

Abstract: A fiducial marker assembly (30) is tracked using a magnetic resonance scanner (10). At the tracked position of the fiducial marker assembly, local B0 magnetic field inhomogeneity is measured. A warning is issued if the measured local B0 magnetic field inhomogeneity satisfies a warning criterion. A noise figure of merit of the tracking is also determined, and the warning is also issued if the noise figure of merit satisfies a noise-based warning criterion.