Abstract: A method and a magnetic resonance tomography unit for tracking a medical instrument are disclosed. In the method, a tracking volume is defined enclosing a predefined trajectory of the medical instrument. Two-dimensional (2D) projection images of the tracking volume in presence of the medical instrument are acquired with the magnetic resonance tomography unit from two different view angles. Reference 2D images for the two view angles are determined and a background of the 2D projection images is suppressed. Two sets of 2D coordinates of the medical instrument are extracted from the two 2D projection images and combined to a 3D coordinate set and output on a display.

Abstract: A method for generating a magnetic resonance image for diagnostic purposes takes segmented k-space data corresponding to a magnetic resonance scanner signal and determines, for each k-space segment, an image sharpness corresponding to a subspace of the k-space data generated by removing that k-space segment from the k-space data. The subspace with the highest sharpness is then used to generate the magnetic resonance image.

Abstract: The present techniques relate to a techniques for performing cardiac perfusion imaging in order to detect perfusion defects in the myocardium. The present techniques relate to methods for performing cardiac perfusion imaging by performing at least two image acquisitions using different, customizable saturation delay times, which improves the ability to detect defects.

Abstract: In a method and apparatus for performing magnetic resonance (MR) imaging for generating multiple T1 maps of separate regions of interest of a subject along a first spatial axis, multiple MR pulse sequences are generated, each MR pulse sequence being for imaging a respective one of the separate regions of interest of the subject. In order to generate each of the plurality of MR pulse sequences, a spatially selective preparation pulse is generated exciting the region of interest of the subject and a number of imaging sequences that follow the application of the spatially selective preparation pulse are generated. MR imaging data are acquired during the generation of the multiple imaging sequences. The multiple MR pulse sequences are generated during a period not exceeding 30 seconds.

Abstract: The present techniques relate to a techniques for performing cardiac perfusion imaging in order to detect perfusion defects in the myocardium. The present techniques relate to methods for performing cardiac perfusion imaging by performing at least two image acquisitions using different, customizable saturation delay times, which improves the ability to detect defects.

Abstract: In a method of performing magnetic resonance imaging and a magnetic resonance apparatus, first MR data are acquired of a region of interest of a subject in the absence of a B1 field. Second MR data are acquired of the region of interest in the presence of a B1 field, and within a short time interval after generation of the B1 field. The first and second MR data are processed to determine a B1 field map, and a T1 map is generated using the B1 field map. The T1 map is a B1 corrected T1 map. The first and second MR data 103, 109 may be acquired as part of a T1 mapping sequence, such as a MOLLI or SASHA type cardiac T1 mapping sequence.

Abstract: A method of estimating a longitudinal magnetic relaxation T1 time for a region of a subject. The method includes providing a computer with at least two magnetic resonance (MR) images of the region of the subject that were respectively acquired at different times after the generation of a preparation pulse during a MR pulse sequence; in said computer, analyzing said at least two MR images in order to obtain, from the same location in each of the MR images, a pixel value, wherein each of the pixel values and the time at which their respective MR image was acquired form a data point; and in said computer, fitting the data points to a model representing said longitudinal magnetic relaxation by varying a single adjustable parameter to estimate the T1 time constant for the region of interest, wherein the single adjustable parameter represents a T1 time constant within the model.

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: Techniques are disclosed for determining coefficients for use in correcting a magnetic relaxation time constant, T, value obtained via magnetic resonance imaging when a pulse rate was at a first pulse rate value to a T value reflecting the T value that would have been obtained if the pulse rate was at a second pulse rate value. The technique includes, for each region of interest, pairing an obtained derivative, m, and an obtained offset, c, as an ordered pair (c, m). The technique further includes fitting the obtained plurality of ordered pairs (c, m) to a polynomial function, and determining the values of the coefficients from the polynomial function.

Abstract: Techniques are disclosed for determining coefficients for use in correcting a magnetic relaxation time constant, T, value obtained via magnetic resonance imaging when a pulse rate was at a first pulse rate value to a T value reflecting the T value that would have been obtained if the pulse rate was at a second pulse rate value. The technique includes, for each region of interest, pairing an obtained derivative, m, and an obtained offset, c, as an ordered pair (c, m). The technique further includes fitting the obtained plurality of ordered pairs (c, m) to a polynomial function, and determining the values of the coefficients from the polynomial function.

Abstract: A method of estimating a longitudinal magnetic relaxation T1 time for a region of a subject. The method includes providing a computer with at least two magnetic resonance (MR) images of the region of the subject that were respectively acquired at different times after the generation of a preparation pulse during a MR pulse sequence; in said computer, analyzing said at least two MR images in order to obtain, from the same location in each of the MR images, a pixel value, wherein each of the pixel values and the time at which their respective MR image was acquired form a data point; and in said computer, fitting the data points to a model representing said longitudinal magnetic relaxation by varying a single adjustable parameter to estimate the T1 time constant for the region of interest, wherein the single adjustable parameter represents a T1 time constant within the model.

Abstract: In a method and apparatus for performing magnetic resonance (MR) imaging for generating multiple T1 maps of separate regions of interest of a subject along a first spatial axis, multiple MR pulse sequences are generated, each MR pulse sequence being for imaging a respective one of the separate regions of interest of the subject. In order to generate each of the plurality of MR pulse sequences, a spatially selective preparation pulse is generated exciting the region of interest of the subject and a number of imaging sequences that follow the application of the spatially selective preparation pulse are generated. MR imaging data are acquired during the generation of the multiple imaging sequences. The multiple MR pulse sequences are generated during a period not exceeding 30 seconds.

Abstract: In a method of performing magnetic resonance imaging and a magnetic resonance apparatus, first MR data are acquired of a region of interest of a subject in the absence of a B1 field. Second MR data are acquired of the region of interest in the presence of a B1 field, and within a short time interval after generation of the B1 field. The first and second MR data are processed to determine a B1 field map, and a T1 map is generated using the B1 field map. The T1 map is a B1 corrected T1 map. The first and second MR data 103, 109 may be acquired as part of a T1 mapping sequence, such as a MOLLI or SASHA type cardiac T1 mapping sequence.

Abstract: In a method of performing magnetic resonance imaging and a magnetic resonance apparatus, a region of interest in a subject in which a material having magnetic susceptibility has been introduced is imaged. A first imaging sequence includes excitation pulses having a frequency that is on-resonance is generated for application to the subject. A second imaging sequence includes excitation pulses having a frequency that is off-resonance is generated for application to the subject. Both the first and second imaging sequences have balanced gradient pulse trains. Signals emitted from the region of the interest in the subject in response to the first and second imaging sequences are detected, and first and second images are generated based on these signals. The first and second images are processed to generate a difference image.

Abstract: An apparatus and method process image data, including motion corrupted data, from a magnetic resonance imaging procedure to obtain and reconstruct images for cardiac, cardiovascular, coronary arterial, and/or pulmonary vein diagnoses in a subject. The apparatus and method include a processor operating predetermined software which receives the image data, classifies the received image data as accepted image data or rejected image data, and applies a predetermined relationship between the accepted image data and the rejected image data to correct for motion of the subject and to generate and output a reconstructed image of the subject corrected for the motion from the image data, with the reconstructed image having a relatively high signal-to-noise ratio.

Abstract: Systems and methods for adaptively registering images acquired with different contrast-weightings using a magnetic resonance imaging (“MRI”) system. For instance, motion is estimated as global affine motion refined by a local non-rigid motion estimation algorithm that simultaneously estimates the motion field and intensity variations among the images being registered. The images registered with the described systems and methods can be used for improved tissue characterization.