摘要:
A method for generating an image comprises: acquiring a magnetic resonance image (DI); generating a magnetic susceptibility gradient vector map (DΔχ) 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.
摘要:
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).
摘要:
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.
摘要:
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. The preliminary magnetic field inhomogeneity values (8) are used as start values for an iterative optimization procedure (19) for determining the final local magnetic field inhomogeneity values.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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. In accordance with the invention, the device 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 of RF pulses and switched magnetic field gradients, b) acquire the MR echo signals for reconstructing an MR image data set (21) therefrom, c) calculate a gradient map (22) by computing echo shift parameters (SPx, SPy, SPz) from subsets of the MR image data set, the echo shift parameters (SPx, SPy, SPz) indicating magnetic field gradient induced shifts of the echo positions in k-space, wherein each subset comprises a number (n) of spatially adjacent pixel or voxel values of the MR image data set (21).