Abstract: Provided herein are systems and methods for generating fetal cardiac magnetic resonance (MR) images of a living fetus, within a uterus of a parent of the fetus, by imaging the fetus within the uterus using a magnetic resonance imaging (MRI) system. Also provided herein are methods for deriving information indicative of fetal cardiac cycles from MR data obtained by an MRI system while imaging the fetus, the MR data including MR data for the center of k-space. The derived information may be used to differentiate the fetal cardiac cycles from other sources of noise in the MR data such as the parental cardiac cycles.

Abstract: A system and method for producing an image of a subject with a magnetic resonance imaging (MRI) system using an adaptive gating window with constant gating efficiency is provided. Navigator data is acquired from the subject and used to produce a gating window having a defined gating efficiency value. Image data is acquired with the MRI system while measuring a position of an anatomical location within the subject. Image data is accepted or rejected based on whether the measured anatomical location is within the gating window. The gating window is updated using the measured position of the anatomical location such that a substantially constant gating efficiency value is maintained. Imaging is repeated with the updated gating window, after which the gating window is again updated. When the desired amount of image data has been acquired, an image of the subject is reconstructed.

Abstract: A method for free-breathing magnetic resonance imaging (MRI) using iterative image-based respiratory motion correction is provided. An MRI system is used to acquired k-space data and navigator data from a subject. The k-space data is then sorted into a plurality of data bins using the navigator data. A motion correction parameter is estimated for each data bin and is applied to the respective k-space data in that bin. The corrected k-space data segments are then combined to form a corrected k-space data set, from which an image is reconstructed. The process may be iteratively repeated until an image quality metric is optimized; for example, until an image sharpness measure is sufficiently maximized.

Abstract: A system and method for producing an image of a subject with a magnetic resonance imaging (MRI) system using an adaptive gating window with constant gating efficiency is provided. Navigator data is acquired from the subject and used to produce a gating window having a defined gating efficiency value. Image data is acquired with the MRI system while measuring a position of an anatomical location within the subject. Image data is accepted or rejected based on whether the measured anatomical location is within the gating window. The gating window is updated using the measured position of the anatomical location such that a substantially constant gating efficiency value is maintained. Imaging is repeated with the updated gating window, after which the gating window is again updated. When the desired amount of image data has been acquired, an image of the subject is reconstructed.

Abstract: A method for free-breathing magnetic resonance imaging (MRI) using iterative image-based respiratory motion correction is provided. An MRI system is used to acquired k-space data and navigator data from a subject. The k-space data is then sorted into a plurality of data bins using the navigator data. A motion correction parameter is estimated for each data bin and is applied to the respective k-space data in that bin. The corrected k-space data segments are then combined to form a corrected k-space data set, from which an image is reconstructed. The process may be iteratively repeated until an image quality metric is optimized; for example, until an image sharpness measure is sufficiently maximized.