Abstract: Example apparatus and methods order projections in a 3D MRI acquisition to achieve improved equidistant spacing or to achieve improved adherence to a target distribution. The equidistant or target spacing may exist in k-space and/or in kt-space. In one embodiment, the improved equidistant spacing is a substantially uniform spacing. The substantially uniform spacing may be achieved using a modification of a charge repulsion analysis that treats points of projections that intersect the surface of a 3D volume to be imaged as point charges distributed on the 3D volume. In another embodiment, the target spacing may be uniform, non-uniform, uniform in parts and non-uniform in other parts, and other combinations.

Abstract: Example apparatus and methods order projections in a 3D MRI acquisition to achieve improved equidistant spacing or to achieve improved adherence to a target distribution. The equidistant or target spacing may exist in k-space and/or in kt-space. In one embodiment, the improved equidistant spacing is a substantially uniform spacing. The substantially uniform spacing may be achieved using a modification of a charge repulsion analysis that treats points of projections that intersect the surface of a 3D volume to be imaged as point charges distributed on the 3D volume. In another embodiment, the target spacing may be uniform, non-uniform, uniform in parts and non-uniform in other parts, and other combinations.

Abstract: Example apparatuses and methods control a magnetic resonance imaging (MRI) apparatus to perform a non-Cartesian, under-sampled, multi-echo MRI process. One example process includes controlling the MRI apparatus to excite an object to be imaged using a multi-echo Gradient Recalled Echo (GRE) pulse sequence. The example process also includes controlling the MRI apparatus to acquire a data set from the object to be imaged as a function of performing a non-Cartesian, under-sampling acquisition. The data set includes data acquired at two or more echo times (TE) per repetition (TR) and an element in the data set is sampled two or more times as a function of a non-Cartesian trajectory that crosses itself at least once. The process also includes controlling the MRI apparatus to reconstruct an image of the object to be imaged from the data set. The image may map brain activity.

Abstract: Example apparatuses and methods control a magnetic resonance imaging (MRI) apparatus to perform a non-Cartesian, under-sampled, multi-echo MRI process. One example process includes controlling the MRI apparatus to excite an object to be imaged using a multi-echo Gradient Recalled Echo (GRE) pulse sequence. The example process also includes controlling the MRI apparatus to acquire a data set from the object to be imaged as a function of performing a non-Cartesian, under-sampling acquisition. The data set includes data acquired at two or more echo times (TE) per repetition (TR) and an element in the data set is sampled two or more times as a function of a non-Cartesian trajectory that crosses itself at least once. The process also includes controlling the MRI apparatus to reconstruct an image of the object to be imaged from the data set. The image may map brain activity.

Abstract: An ultrasonic tracking system embodying the invention has an array of plural ultrasonic detectors at discrete locations, the plural detectors being responsive to an ultrasonic signal of frequency f emanating from a single remote transmitter to produce respective plural electronic signals corresponding to the ultrasonic signal as received at respective ones of the plural detectors, and a processor for determining from the plural electronic signals a direction of travel of the ultrasonic signal relative to the array of ultrasonic detectors. In order to provide range, a phase shift key encoder connected to the transmitter encodes every N cycles of the ultrasonic signal with one of a succession of encoder counts, while a phase shift key decoder coupled to receive an electronic signal from one of the plural detectors produces a new decoder count every N cycles of the electronic signal that are decodable.