Abstract: A method for equilibrium phase contrast-enhanced magnetic resonance (MR) angiography using an extracellular MR contrast agent administered to a subject includes performing a balanced T1 relaxation enhanced steady-state (bT1RESS) pulse sequence to acquire MR data from a region of interest of the subject during an equilibrium phase of contrast enhancement after a first pass of the extracellular contrast agent through the region of interest. The bT1RESS pulse sequence includes a T1-weighted magnetization preparation including at least one contrast modifying (CM) radio frequency (RF) pulse, a single-shot balanced steady-state free precession (bSSFP) readout, and a time interval between the T1-weighted magnetization preparation and the acquisition of a center of k-space. The time interval is determined based on a T1 relaxation time of a contrast-enhanced blood pool and a flip angle of the at least one CM RF pulse. The method further includes generating an angiographic image of the region of interest.

Abstract: A system and method for a non-contrast enhanced magnetic resonance imaging technique using a temporal maximum intensity projection reconstructed from multiple temporal subsets of data acquired the acquisition window. The method includes applying a radiofrequency pulse to the subject, waiting a quiescent interval, performing a radial acquisition with a golden-angle view angle increment over a duration corresponding to a cardiac cycle of the subject to generate acquisition data, reconstructing a plurality of images across a plurality of temporal phases from the acquisition data and generating a temporal maximum intensity projection image by tracking an intensity of each pixel across the plurality of images and selecting the pixel having a maximum intensity value across the plurality of images.

Abstract: A dark blood magnetic resonance imaging (MRI) imaging technique utilizes a time-reversed steady-state free precession (SSFP) pulse sequence, in which magnetic field gradients are unbalanced along at least one gradient axis, but balanced along at least one of the other gradient axes. The pulse sequence can include interrupted shots, in which subsequent shots or repetitions of the pulse sequence are not continuous in time. For example, the pulse sequence can be gated based on cardiac signals, respiratory signals, or navigator data, or may be otherwise discontinuous over time.

Abstract: A method for generating magnetic resonance images of a subject includes performing, using a magnetic resonance imaging (MRI) system, an interrupted three-dimensional (3D) single shot unbalanced steady-state free precession (uSSFP) pulse sequence to acquire MR data for each of a plurality of partitions associated with a region of interest of a subject. The interrupted 3D single shot uSSFP pulse sequence may be configured to suppress blood signal in the region of interest. The MR data for each partition is acquired as a single shot along an in-plane phase-encoding direction and the acquisition of MR data for each partition is synchronized to a phase of a cardiac cycle. The method further includes generating, using a processor, an image with blood suppression based on the acquired MR data.

Abstract: A method for generating magnetic resonance (MR) images of a subject includes performing, using a magnetic resonance imaging (MRI) system, a steady-state pulse sequence to acquire MR data from a region of interest in the subject. The steady-state pulse sequence includes a contrast-modifying (CM) radio frequency (RF) pulse applied periodically at a predetermined time interval followed by a gradient spoiler pulse. The CM RF pulse has a flip angle with a value determined based on a minimum Ernst angle for a set of one or more background tissues in the region of interest that the CM RF pulse is configured to suppress with respect to a tissue of interest. The method further includes generating an image with Ti contrast based on the acquired MR data.

Abstract: A method for generating magnetic resonance images of a subject includes performing, using a magnetic resonance imaging (MRI) system, a magnetization preparation module to control tissue contrast for a region of interest in the subject. The method further includes after a predetermined period of time, performing, using the MRI system, a three dimensional (3D) unbalanced steady-state free precession (uSSFP) pulse sequence to acquire MR data from the region of interest in the subject. The 3D uSSFP pulse sequence is configured to suppress blood signal in the region of interest. The method further includes generating an image with blood signal suppression based on the acquired MR data.

Abstract: A method for generating magnetic resonance images of a subject includes performing, using a magnetic resonance imaging (MRI) system, an interrupted three-dimensional (3D) single shot unbalanced steady-state free precession (uSSFP) pulse sequence to acquire MR data for each of a plurality of partitions associated with a region of interest of a subject. The interrupted 3D single shot uSSFP pulse sequence may be configured to suppress blood signal in the region of interest. The MR data for each partition is acquired as a single shot along an in-plane phase-encoding direction and the acquisition of MR data for each partition is synchronized to a phase of a cardiac cycle. The method further includes generating, using a processor, an image with blood suppression based on the acquired MR data.

Abstract: A method for producing an image representative of the vasculature of a subject using a MRI system includes the acquisition of a signal indicative of a subject' cardiac phase. During each heartbeat of the subject, image slices of a volume covering a region of interest (ROI) within the subject are acquired by applying a volume-selective venous suppression pulse to suppress (a) venous signal for an upper slice in the ROI; (b) venous signal for slices that are upstream for venous flow in the ROI; and (c) background signal from the upstream slices. Next, a slice-selective background suppression pulse is applied to suppress background signal of the upper slice. Following a quiescent time interval, a spectrally selective fat suppression pulse is applied to the entire volume to attenuate signal from background fat signal. Then, a simultaneous multi-slice acquisition of the upper slice and the upstream slices is performed.

Abstract: A system and method for a non-contrast enhanced magnetic resonance imaging technique using a temporal maximum intensity projection reconstructed from multiple temporal subsets of data acquired the acquisition window. The method includes applying a radiofrequency pulse to the subject, waiting a quiescent interval, performing a radial acquisition with a golden-angle view angle increment over a duration corresponding to a cardiac cycle of the subject to generate acquisition data, reconstructing a plurality of images across a plurality of temporal phases from the acquisition data and generating a temporal maximum intensity projection image by tracking an intensity of each pixel across the plurality of images and selecting the pixel having a maximum intensity value across the plurality of images.

Abstract: A system and method for controlling a magnetic resonance imaging (MRI) system to create magnetic resonance (MR) cine angiograms of a subject. The method includes controlling the MRI system to acquire MR data from the subject by performing at least one cine acquisition pulse sequence having a plurality of acquisition RF pulse modules applied at constant intervals throughout a cardiac cycle, and at least one labeling pulse sequence including a first and a second ?/2 module and a labeling RF pulse module for labeling a region of inflowing arterial flow through a vessel of interest. The method further includes reconstructing the MR data to form a series of cine frames that form a cine angiogram, subtracting at least one cine frame from other cine frames reconstructed from the MR data, and displaying the MR cine angiogram of the vessel of interest.

Abstract: A system and method for controlling a magnetic resonance imaging (MRI) system to create magnetic resonance (MR) angiograms of a subject. The method includes controlling the MRI system to acquire MR data by performing a pulse sequence that includes at least one set of modules formed by a first ?/2 module, a (readout, ?)n module, a second ?/2 module. In this case, ? denotes a radiofrequency (RF) flip angle and n denotes a number of times that the set of modules is repeated. The method also includes reconstructing an MR angiogram of the subject from the MR data.

Abstract: A method for producing an image representative of the vasculature of a subject using a MRI system includes the acquisition of a signal indicative of a subject' cardiac phase. During each heartbeat of the subject, image slices of a volume covering a region of interest (ROI) within the subject are acquired by applying a volume-selective venous suppression pulse to suppress (a) venous signal for an upper slice in the ROI; (b) venous signal for slices that are upstream for venous flow in the ROI; and (c) background signal from the upstream slices. Next, a slice-selective background suppression pulse is applied to suppress background signal of the upper slice. Following a quiescent time interval, a spectrally selective fat suppression pulse is applied to the entire volume to attenuate signal from background fat signal. Then, a simultaneous multi-slice acquisition of the upper slice and the upstream slices is performed.

Abstract: A method for dual-contrast unenhanced magnetic resonance angiography includes iteratively acquiring flow-dependent slices and flow-independent slices in a region. Each iteration of the acquisition process comprises identifying a flow-dependent slice location within the region and identifying a flow-independent slice location upstream from the flow-dependent slice location according to blood flow in the region. Each iteration further includes applying a first radio frequency (RF) saturation pulse to the region such that MR signals from veins in the region are substantially suppressed, and applying a second RF saturation pulse to the flow-dependent slice location such that MR signals from background muscle and arterial blood in the region are substantially suppressed. A flow independent slice is acquired at the flow-independent slice location after the second RF saturation pulse is applied and before unsaturated arterial blood has maximally flowed into the region.

Abstract: A method for producing an image representative of the vasculature of a subject using a MRI system includes the acquisition of a signal indicative of a subject' cardiac phase. During each heartbeat of the subject, image slices of a volume covering a region of interest (ROI) within the subject are acquired by applying a volume-selective venous suppression pulse to suppress (a) venous signal for an upper slice in the ROI; (b) venous signal for slices that are upstream for venous flow in the ROI; and (c) background signal from the upstream slices. Next, a slice-selective background suppression pulse is applied to suppress background signal of the upper slice. Following a quiescent time interval, a spectrally selective fat suppression pulse is applied to the entire volume to attenuate signal from background fat signal. Then, a simultaneous multi-slice acquisition of the upper slice and the upstream slices is performed.

Abstract: A system and method for controlling a magnetic resonance imaging (MRI) system to create magnetic resonance (MR) cine angiograms of a subject. The method includes controlling the MRI system to acquire MR data from the subject by performing at least one cine acquisition pulse sequence having a plurality of acquisition RF pulse modules applied at constant intervals throughout a cardiac cycle, and at least one labeling pulse sequence including a first and a second ?/2 module and a labeling RF pulse module for labeling a region of inflowing arterial flow through a vessel of interest. The method further includes reconstructing the MR data to form a series of cine frames that form a cine angiogram, subtracting at least one cine frame from other cine frames reconstructed from the MR data, and displaying the MR cine angiogram of the vessel of interest.

Abstract: Described here are systems and methods for generating projection angiograms with enhanced background suppression. Images are acquired with an MRI system at different echo times (e.g., a first and second echo time) in a given repetition time period. A mask image is generated based on the images, such as by computing a difference between the images. The mask image is scaled by different scale factors computed based on the different images. The scale factors are computed based on a ratio of a selected tissue signal (e.g., fat signal) in each image and the mask image. The scaled mask images are subtracted from the respective images and a projection angiograms are produced from these processed images.

Abstract: Systems and methods for acquiring magnetic resonance images that accurately depict vascular calcifications, or other objects composed of magnetic susceptibility-shifted substances, in a subject are provided. The images are generally acquired using a pulse sequence that is designed to reduce physiological motion-induced artifacts and to mitigate chemical-shift artifacts from water-fat boundaries. Advantageously, the MRI technique described here suppresses chemical-shift artifacts without significantly reducing the signal intensity from fatty tissues, and thereby allows for more reliable visualization of vascular calcifications.

Abstract: Systems and methods for magnetic resonance imaging (“MRI”), in which accurate and conspicuous visualization of vascular calcifications and other bony structures can be achieved. An MRI system is operated to perform a pulse sequence that generates substantially similar signal intensity from soft tissues (e.g. muscle, fat, blood) within the body. For instance, blood can be rendered to have a signal intensity that is substantially similar to the vessel wall, while fat and muscle are rendered to appear substantially similar to the vessel wall. With this “neutral” contrast, arterial calcifications, which appear dark due to their low proton density, can be more readily and efficiently visualized by an interpreting physician.

Abstract: A method of acquiring magnetic resonance imaging (MRI) data of a subject includes dividing a region of interest into a plurality of slices, and acquiring the slices using an iterative process that interleaves acquisition of shim data covering the plurality of slices with acquisition of image data covering the slices over a plurality of iterations.

Abstract: Embodiments relate to a method and system to improve fat suppression and reduce motion and off-resonance artifacts in magnetic resonance imaging (MRI) by using a background-suppressed, reduced field-of-view (FOV) radial imaging. The reduction of such artifacts provides improved diagnostic image quality, higher throughput of MRI scans for the imaging center, and increased patient comfort. By using a small FOV radial acquisition that only encompasses the structures of interest, structures that cause motion artifacts, such as the anterior abdominal wall, bowel loops, or blood vessels with pulsatile flow, are excluded from the image. According to an embodiment, combining a small FOV radial acquisition with one or more background-suppression techniques minimizes the impact of artifacts caused by anatomy outside of the FOV.