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 system (10) and method generate one or more MR data sets of an imaging volume (16) using an MR scanner (14). The imaging volume (16) includes one or more of a region of interest (ROI), the ROI including a metal element, and a local receive coil (18) of the MR scanner (14). At least one of an attenuation, confidence or density map accounting for the metal element is generated and the location of the local receive coil (18) within the imaging volume (16) is determined. The generating includes identification of the metal element within the ROI based on a phase map of the ROI generated from the MR data sets. The determining includes registering a known sensitivity profile of the local receive coil (18) to a sensitivity map of the local receive coil (18) generated from the MR data sets.

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: An MR method and apparatus determines spatially resolved relaxation parameters of a subject in an examination zone, voxel by voxel. A first MR scan sequence is applied to generate a series of first MR data sets having different echo times. A second MR scan sequence is applied to generate at least one further MR data set having an enhanced spatial resolution and reduced time resolution in comparison with the first MR data sets from the first sequence. MR combination images are generated using the first MR data sets derived from the first sequence for a portion within the k-space and the further MR data set acquired outside this portion by the second sequence. The relaxation parameters are determined from the MR combination images.

Abstract: A method for generating an image comprises: acquiring a magnetic resonance image (DI); generating a magnetic susceptibility gradient vector map (D??) from the magnetic resonance image; and filtering the magnetic susceptibility gradient vector map to generate a magnetic susceptibility gradient image (96, 110) depicting magnetic susceptibility gradient information including at least some magnetic susceptibility gradient directional information.

Abstract: A medical imaging method includes energy-resolving x-ray projection data indicative of a contrast labeled scaffold seeded with biological cells for growing tissue and reconstructing the energy-resolved projection data to generate energy-resolved image data indicative of the contrast labeled scaffold.

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: An MR method determines local relaxation time values (T1, T2) of an examination object (5). First, two or more MR images (3, 4) of the examination object (5) are recorded, each with different time parameter sets (TR1, TE1, TR2, TE2) of an imaging sequence. MR images (6, 7) of a phantom are likewise recorded using the same time parameter sets (TR1, TE1, TR2, TE2) of the imaging sequence. The phantom has a known spatial distribution of relaxation time values (T1, T2). The local relaxation time values (T1, T2) of the examination object (5) are determined by comparing image values of the MR images (3, 4) of the examination object (5) with image values of the MR images (6, 7) of the phantom and by assigning image values of the MR images (6, 7) of the phantom to relaxation time values (T1, T2) according to the known spatial distribution of relaxation time values (T1, T2) of the phantom.

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: The invention relates to a device for magnetic resonance imaging of a body (7), wherein the device (1) is arranged to a) generate a series of MR echo signals (20) by subjecting at least a portion of the body (7) to an MR imaging sequence comprising RF pulses and switched magnetic field gradients, b) acquire the MR echo signals for reconstructing an MR image (21) therefrom, c) calculate a susceptibility gradient map (22) from the MR echo signals or from the MR image (21), the susceptibility gradient map (22) indicating local susceptibility induced magnetic field gradients, d) determine the position of an interventional instrument (16) having paramagnetic or ferromagnetic properties from the susceptibility gradient map (22).

Abstract: MR based molecular imaging is strongly supported by the accurate quantification of contrast agents. According to an exemplary embodiment of the present invention, a determination unit of an examination apparatus is adapted for determining an error propagation function, wherein the error propagation function is then used as a weighting function for an accurate determination Of AR2*. This leads to an improved examination result.

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: MR based molecular imaging is strongly supported by the accurate quantification of contrast agents. According to an exemplary embodiment of the present invention, a determination unit of an examination apparatus is adapted for determining an error propagation function, wherein the error propagation function is then used as a weighting function for an accurate determination Of AR2*. This leads to an improved examination result.

Abstract: The invention relates to an MR method of determining local relaxation time values (T1, T2) of an examination object (5). Firstly, two or more MR images (3, 4) of the examination object (5) are recorded, each with different time parameter sets (TR1, TE1, TR2, TE2) of an imaging sequence. MR images (6, 7) of a phantom are likewise recorded, wherein the same time parameter sets (TR1, TE1, TR2, TE2) of the imaging sequence are used and wherein the phantom has a known spatial distribution of relaxation time values (T1, T2). The local relaxation time values (T1, T2) of the examination object (5) are determined by comparing image values of the MR images (3, 4) of the examination object (5) with image values of the MR images (6, 7) of the phantom and by assigning image values of the MR images of the phantom to relaxation time values (T1, T2) according to the known spatial distribution of relaxation time values (T1, T2) of the phantom.