Abstract: A method for reordering a segmented MRI pulse sequence includes synchronizing to a physiologic signal of a heart or vessel, to a respiratory signal, or to an external trigger source, and acquiring a plurality of data collecting segments as a contiguous block in a phase encoding direction such that lines of the plurality of data collecting segments are alternately acquired in a forward direction and a reverse direction for each consecutive data collecting segment.

Abstract: A system and method comprises execution of a segmented magnetic resonance imaging pulse sequence, the pulse sequence including a plurality of shots, each of the plurality of shots including an inversion recovery preparation pulse and acquiring a respective segment of k-space lines, wherein each shot comprises a different inversion time between a peak of the inversion recovery pulse and a midpoint of the acquisition of the respective segment of k-space lines, and reconstruction of an image based on the acquired respective segments of k-space lines. In some aspects, the k-space lines acquired by each shot are consecutive in a phase encoding direction of k-space and each shot acquires the segments of k-space lines acquired by prior shots in the sequence, and a time delay between the inversion recovery preparation pulse and acquisition of a first segment for each shot is equal.

Abstract: A T1-weighted turbo-spin-echo magnetic resonance imaging system configured to capture data associated with a subject's heart during a time period and produce MR images has a dark-blood preparation module, a data capture module, and an image reconstruction module. The dark-blood preparation module performs dark-blood preparation through double inversion during some, but not all of the heartbeats within the time period. The data capture module configured performs data readouts to capture imaging data of an imaging slice during every heartbeat in which dark-blood preparation is performed. The data capture module also performs a steady state maintenance step during every heartbeat in which dark-blood preparation is not performed in order to maintain maximum T1-weighting. The image reconstruction module configured to reconstruct a T1-weighted image based on the imaging data.

Abstract: A system comprises determination of an inversion-recovery or saturation-recovery imaging pulse sequence associated with first values of echo spacing, flip angle, effective TR, trigger pulses, artifact post-suppression, and number of image data lines per acquisition, execution of a scout pulse sequence comprising a plurality of single-shot image data acquisitions to acquire respective sets of image data lines, where each of the plurality of single-shot image data acquisitions is executed using a different respective inversion time and where each of the plurality of single-shot image data acquisitions is associated with second values of echo spacing, flip angle, and number of image data lines per acquisition which are substantially similar to corresponding ones of the first values, generation of a plurality of images based on the respective sets of image data lines, determination of one of the plurality of images, the determined one of the plurality of images generated based on a set of image data lines acquire

Abstract: A T1-weighted turbo-spin-echo magnetic resonance imaging system configured to capture data associated with a subject's heart during a time period and produce MR images has a dark-blood preparation module, a data capture module, and an image reconstruction module. The dark-blood preparation module performs dark-blood preparation through double inversion during some, but not all of the heartbeats within the time period. The data capture module configured performs data readouts to capture imaging data of an imaging slice during every heartbeat in which dark-blood preparation is performed. The data capture module also performs a steady state maintenance step during every heartbeat in which dark-blood preparation is not performed in order to maintain maximum T1-weighting. The image reconstruction module configured to reconstruct a T1-weighted image based on the imaging data.

Abstract: A method for determining time periods of minimal motion of a physiologic organ includes monitoring a physiologic triggering signal associated with a patient and using an MRI cine pulse sequence to acquire a temporal series of projections of the organ. The temporal series is analyzed to determine times relative to a physiologic triggering signal during which motion of the organ is below a threshold. Motion is assessed by first creating a signal intensity versus time curve of one pixel or an average of multiple pixels included in the temporal series. A noise filter and normalization is applied to the signal intensity versus time curve to yield a filtered and normalized time curve. The temporal derivative of the filtered and normalized time curve is determined. The absolute value of the motion-analog function is evaluated for being smaller than the threshold to determine the times where motion is below the threshold.

Abstract: A method for correcting image inhomogeneity includes acquiring a non-normalized image and a reference image using receiver coils. A high-signal mask and a low-signal mask are created. Each pixel in the high-signal mask is set to a predetermined integer value if the reference image pixel at the same specific location has a value above a threshold value. Each pixel in the low-signal mask is set to the predetermined integer value if the reference image pixel at the same specific location has a value below or equal to the threshold value. A coil normalization map is created by smoothing the reference image with filters. Then, an iterative procedure is performed to update the coil normalization map using the high-signal mask and the low-signal mask. Following the iterative procedure, the non-normalized image is divided by the current coil normalization map to yield a normalized image.

Abstract: A system comprises determination of an inversion-recovery or saturation-recovery imaging pulse sequence associated with first values of echo spacing, flip angle, effective TR, trigger pulses, artifact post-suppression, and number of image data lines per acquisition, execution of a scout pulse sequence comprising a plurality of single-shot image data acquisitions to acquire respective sets of image data lines, where each of the plurality of single-shot image data acquisitions is executed using a different respective inversion time and where each of the plurality of single-shot image data acquisitions is associated with second values of echo spacing, flip angle, and number of image data lines per acquisition which are substantially similar to corresponding ones of the first values, generation of a plurality of images based on the respective sets of image data lines, determination of one of the plurality of images, the determined one of the plurality of images generated based on a set of image data lines acquire

Abstract: A method for correcting image inhomogeneity includes acquiring a non-normalized image and a reference image using receiver coils. A high-signal mask and a low-signal mask are created. Each pixel in the high-signal mask is set to a predetermined integer value if the reference image pixel at the same specific location has a value above a threshold value. Each pixel in the low-signal mask is set to the predetermined integer value if the reference image pixel at the same specific location has a value below or equal to the threshold value. A coil normalization map is created by smoothing the reference image with filters. Then, an iterative procedure is performed to update the coil normalization map using the high-signal mask and the low-signal mask. Following the iterative procedure, the non-normalized image is divided by the current coil normalization map to yield a normalized image.

Abstract: A magnetic resonance imaging system and method are provided for improved phase-sensitive magnetic resonance imaging of tissues affected by cardiovascular pulsatile motion. A magnetically-prepared image dataset and corresponding reference image dataset (for phase sensitivity) are obtained within the duration of a single cardiac cycle. The paired datasets can be single-shot or segmented datasets and a navigator sequence can optionally be provided with each paired dataset. The system and method take advantage of the shape symmetry of the cardiac cycle to acquire the paired dataset in a shorter time interval, thereby reducing misregistration artifacts. The magnetic preparation can include inversion recovery pulses, FIDDLE sequences, other magnetic preparation sequences, or combinations thereof. The reference dataset can be acquired at a lower resolution than the corresponding magnetically-prepared dataset without compromising image quality.

Abstract: A T1-weighted turbo-spin-echo magnetic resonance imaging system configured to capture data associated with a subject's heart during a time period and produce MR images has a dark-blood preparation module, a data capture module, and an image reconstruction module. The dark-blood preparation module performs dark-blood preparation through double inversion during some, but not all of the heartbeats within the time period. The data capture module configured performs data readouts to capture imaging data of an imaging slice during every heartbeat in which dark-blood preparation is performed. The data capture module also performs a steady state maintenance step during every heartbeat in which dark-blood preparation is not performed in order to maintain maximum T1-weighting. The image reconstruction module configured to reconstruct a T1-weighted image based on the imaging data.

Abstract: A method for determining time periods of minimal motion of a physiologic organ includes monitoring a physiologic triggering signal associated with a patient and using an MRI cine pulse sequence to acquire a temporal series of projections of the organ. The temporal series is analyzed to determine times relative to a physiologic triggering signal during which motion of the organ is below a threshold. Motion is assessed by first creating a signal intensity versus time curve of one pixel or an average of multiple pixels included in the temporal series. A noise filter and normalization is applied to the signal intensity versus time curve to yield a filtered and normalized time curve. The temporal derivative of the filtered and normalized time curve is determined. The absolute value of the motion-analog function is evaluated for being smaller than the threshold to determine the times where motion is below the threshold.

Abstract: A method of fat suppression during magnetic resonance imaging includes applying a fat suppression module to a region of interest within a subject. The fat suppression module comprises a fat-selective saturation pulse; a first spoiler gradient applied following the fat-selective saturation pulse; a fat-selective inversion pulse applied to the region of interest following a time delay; and a second spoiler gradient applied following the fat-selective inversion pulse. The time delay is selected to allow T1 recovery in the region of interest to a predetermined level of fat magnetization at the end of the time delay. Following application of the fat suppression module, a sequence readout is performed to acquire one or more lines of k-space data covering the region of interest.

Abstract: An imaging system comprises determination of a charge block for each building block of an MRI pulse sequence and for each readout event of the MRI pulse sequence, determination, for each charge block, of a charge per request associated with the charge block, determination, for each charge block, of an associated charge reduction based on a charge per request associated with the charge block and on a charge available to the charge block after execution of a previous charge block of the MRI pulse sequence, determination, for each charge block associated with a non-zero charge reduction, of a flip angle of a corresponding building block of the MRI pulse sequence based on a charge per request and a charge reduction associated with the charge block, and control of a radio frequency system to deliver the MRI pulse sequence based on the determined flip angles of each building block of the MRI pulse sequence corresponding to a charge block associated with a non-zero charge reduction.

Abstract: A method of fat suppression during magnetic resonance imaging includes applying a fat suppression module to a region of interest within a subject. The fat suppression module comprises a fat-selective saturation pulse; a first spoiler gradient applied following the fat-selective saturation pulse; a fat-selective inversion pulse applied to the region of interest following a time delay; and a second spoiler gradient applied following the fat-selective inversion pulse. The time delay is selected to allow T1 recovery in the region of interest to a predetermined level of fat magnetization at the end of the time delay. Following application of the fat suppression module, a sequence readout is performed to acquire one or more lines of k-space data covering the region of interest.

Abstract: A magnetic resonance imaging system and method are provided for improved phase-sensitive magnetic resonance imaging of tissues affected by cardiovascular pulsatile motion. A magnetically-prepared image dataset and corresponding reference image dataset (for phase sensitivity) are obtained within the duration of a single cardiac cycle. The paired datasets can be single-shot or segmented datasets and a navigator sequence can optionally be provided with each paired dataset. The system and method take advantage of the shape symmetry of the cardiac cycle to acquire the paired dataset in a shorter time interval, thereby reducing misregistration artifacts. The magnetic preparation can include inversion recovery pulses, FIDDLE sequences, other magnetic preparation sequences, or combinations thereof. The reference dataset can be acquired at a lower resolution than the corresponding magnetically-prepared dataset without compromising image quality.

Abstract: An imaging system comprises determination of a charge block for each building block of an MRI pulse sequence and for each readout event of the MRI pulse sequence, determination, for each charge block, of a charge per request associated with the charge block, determination, for each charge block, of an associated charge reduction based on a charge per request associated with the charge block and on a charge available to the charge block after execution of a previous charge block of the MRI pulse sequence, determination, for each charge block associated with a non-zero charge reduction, of a flip angle of a corresponding building block of the MRI pulse sequence based on a charge per request and a charge reduction associated with the charge block, and control of a radio frequency system to deliver the MRI pulse sequence based on the determined flip angles of each building block of the MRI pulse sequence corresponding to a charge block associated with a non-zero charge reduction.

Abstract: A method for manipulating magnetic resonance signals of a first chemical species and a second chemical species includes determining a time required to have spins of protons corresponding to the first chemical species acquire a phase shift of 90 degrees relative to spins of protons corresponding to second chemical species. A first pulse portion having a pulse amplitude and a first constant phase is defined. A second pulse portion having the pulse amplitude and a second constant phase, the second constant phase being different from said first constant phase by a multiple of 90 degrees is also defined. Next, a single continuous composite pulse is generated by concatenating the first pulse portion and the second pulse portion, wherein the single continuous composite pulse has a duration such that a time difference between center of the first pulse portion and center of the second pulse portion corresponds to the determined time.

Abstract: A virtual frequency selective inversion (VFSI) method receives at least one MR image representative dataset and an associated phase reference dataset, and classifies anatomical material into a first component representing anatomical material having a first range of resonance frequencies associated with a first range of phase differences between the MR image representative dataset and the associated phase reference image dataset, and a second component representing anatomical material having a second range of resonance frequencies associated with a second range of phase differences between the MR image representative dataset and the associated phase reference image dataset. The method assigns different visual attributes to first and second components derived using phase differences between the MR image representative dataset and the reference image dataset and displays an image.

Abstract: An MR system acquires, over multiple heart cycles, image datasets representing multiple image slices of an anatomical region of interest of a patient. In the device, an RF signal generator and a magnetic field gradient generator provides an RF pulse and magnetic field gradient sequence for RF signal excitation of the region of interest and for acquiring RF data following the signal excitation. The sequence comprises, a first sequence occurring substantially immediately after the acquisition of image data using a readout magnetic field gradient. The first sequence includes an RF pulse with a predetermined flip angle followed by a magnetic field gradient pulse for reducing field magnetization to substantially zero. The first sequence is preceded by a dummy acquisition sequence comprising the elements of the first sequence except substantially without acquisition of data.