Abstract: A multi-channel phased array coil for use in a magnetic resonance (MR) system is disclosed herein. The phased array coil includes N coils configured in an array, each of the N coils having a geometric shape and overlapping with (N−1) coils to form an overlap area within the array. The geometric shape of each of the coils and the overlap area are configured to cause a mutual inductance between every pair of the coils to be less than 10 percent of the self-inductance of each of the N coils. At least four coils are provided in the phased array coil.

Abstract: A method and system for designing a radio frequency (RF) coil assembly is disclosed herein. The designing scheme or tool includes determining a self inductance by solving analytically or numerically two-dimensional boundary value problems s. The scheme further includes determining at least one mutual inductance by solving analytically or numerically the two-dimensional boundary value problems. The ratio of the mutual inductance and the self inductance represents a magnetic coefficient of coupling of the RF coil assembly.

Abstract: A gas stream monitoring system including a low cost main stream gas analyzer system is disclosed herein. The low cost main stream gas analyzer system is calibrated by a side stream gas analyzer system included in the gas stream monitoring system. Once calibrated, the side stream system is placed into standby mode such that diversions of portions of the gas stream can be minimized. The calibrated output signals from the low cost main stream system contain corrections for gas interference, pressure change, temperature change, manufacturing tolerance, component flaws, and any other sources of error.

Abstract: One aspect of the present invention is a method that includes helically scanning an object at a selected helical pitch to acquire projection data of the object. The acquired projection data includes conjugate samples from single rows of the detector array of the CT imaging system and interrow samples. Projections in a plane of reconstruction (POR) are estimated based upon a selection of the projection data from the group consisting of the conjugate samples from at least one of the single rows, the interrow samples, and combinations thereof, the selection dependent upon the selected helical pitch. The estimated projections are filtered and backprojected to reconstruct at least one image of the object.

Abstract: An x-ray imaging apparatus having an anode stem assembly with explosion-bonded joints is provided. Explosion-bonding the components of an anode stem assembly to one another provides a hermetic seal with increased reliability as well as reducing the anode stem's susceptibility to thermal and/or mechanical induced fracture. By eliminating the need for brazing and/or welding material within the anode stem, the present invention also provides an anode stem with increased heat transfer capabilities. Further, providing explosion-bonded joints creates a simple joint microstructure absent any voids and temperature-induced phases not previously present in the anode stem materials.

Abstract: A method and apparatus for correcting ghosting artifacts that are related to Maxwell fields and/or other perturbation magnetic fields is disclosed. The method and apparatus includes acquiring MR image n-space data and an MR reference scan, each having perturbation field effects therein. After determining phase correction values from the MR reference scan and reconstructing an MR image using the phase correction values, a projection phase error is calculated from the reconstructed MR image and then subtracted from the reference scan, the result of which is used to determine a new set of phase correction values. The new set of phase correction values is applied to the acquired MR image data to reconstruct a new image. The reconstructed new image can then be reused to calculate a new projection phase error, which again is subtracted from the reference scan data and the process is repeated until an image of desired ghost artifact reduction is achieved.

Abstract: An object location monitoring system tracks the locations of portable transceivers that attach to movable objects, such as patients within a hospital. The system preferably tracks the locations of the transceivers by combining a signal strength based locating process with a topological tracking process. Beacons that intermittently transmit unique ID codes are mounted to walls or other structures throughout a building, and are maintained in synchronization using the 60 Hz cycle of a standard 120V AC power signal, either directly or by monitoring flicker of fluorescent lighting. The transceivers receive the transmissions of nearby beacons, determine the signal strengths of such transmissions, and forward associated data to a server. The server uses this data to determine the location of each transceiver, and uses expected travel times between specific locations to resolve ambiguities.

Abstract: In one aspect, there is provided a method for reducing aliasing artifacts in a computed tomography system. The method includes scanning an object with a computed tomography system to acquire a projection data set of measured views; synthesizing additional views of the projection data set utilizing view interpolation; and filtering and backprojecting the projection data set utilizing a weighting function dependent upon parameters Rƒ and Rt, where radius Rƒ around an isocenter of the CT imaging system is selected in accordance with a low artifact criterion and Rt is a parameter defining a transition region outside of radius Rƒ around the isocenter of the CT imaging system.

Abstract: Various designs and features of an ambulatory transceiver and ECG lead set are disclosed for use in remote patient monitoring. One feature involves the use of unshielded, dual-conductor lead wires in which one conductor carries the patient's ECG signal and the other conductor provides an RF antenna element for the transceiver. The lead wires used in one embodiment provide improved flexibility, durability, and antenna performance over conventional lead sets with shielded wires. Another feature involves an antenna diversity scheme in which the transceiver switches between two or more ECG-lead antennas, each of which is formed from one or more ECG leads of the lead set. Another feature involves the use of a circuit within the transceiver to monitor, and dynamically compensate for changes in, the impedance of an ECG-lead antenna or a conductor thereof. Another feature is an improved circuit for protecting the transceiver from damage caused by defibrillation pulses.

Abstract: A method and apparatus are disclosed for achieving suppression of blood pool signal to detect myocardial infarction using MR technology. After administering a contrast agent into the blood stream of a patient, an RF pulse sequence is applied that includes a slice-selective inversion pulse to suppress normal myocardial tissue followed by a notched inversion RF pulse designed to suppress blood pool in and around the region-of-interest. MR data is then acquired within the region-of-interest that not only has signals from normal myocardial tissue suppressed, but also has blood pool signal suppression to improve delineation of infarcted myocardium from the ventricular blood pool and normal myocardium.

Abstract: A detector module includes a photosensor array having a first width, and a flexible cable operationally coupled to the photosensor array, wherein the cable has a width greater then the first width.

Abstract: An apparatus and method that allows an operator to initiate a prep delay sequence from an area adjacent a patient table are provided for use with x-ray emitting scanners. An operator is allowed to maintain continued focus on a patient to be scanned and closely monitor the patient during the injection sequence. Overall scan time is reduced by decreasing the number of times the operator must travel between the operator console and the patient table. Risk to prolonged radiation exposure is thereby reduced. Ultimately, the present invention allows for better quality patient care, faster scan times and overall increased throughput, reduced repetitive tasks for the operators, reduced risk of x-ray exposure to operators, and, in some circumstances, eliminating the need for multiple operators.

Abstract: The present invention provides a control used in conjunction with a vacuous chamber enclosing the gradient coils of an MRI apparatus to predict heat dissipation requirements to maintain internal and external temperatures below maximum operating limits thereby enabling higher power applications for faster-imaging with improved quality, as well as allowing longer scan times for interventional procedures. The control includes determining operating parameters of an imminent scan session and predicting therefrom maximum and minimum operating temperatures. The predicted maximum and minimum temperatures are compared to maximum and minimum temperatures required for proper operation of the MRI system. If necessary, the operating profile is adjusted to drive the predicted temperatures to satisfy the temperatures required by environmental and device guidelines.

Abstract: A medical telemetry system includes a procedure alarm silence feature that enables a clinician to remotely disable a monitoring station alarm in order to perform a patient procedure that might cause inadvertent false alarms. To disable the alarm for a preprogrammed time interval, the clinician presses keys on the telemetry unit according to a predefined key sequence that is selected so as to reduce a likelihood of accidental alarm disablement. The monitoring system responds to the predefined sequence by disabling an audible alarm for all alarm conditions except class 1 arrhythmias. A corresponding visual alarm at the monitoring station is maintained active. While the alarm is disabled, the monitoring station displays an indication of the amount of time until expiration of the preprogrammed time interval.

Abstract: A method for reducing imaging artifacts in at least one image representative of an object with a scanning imaging system is provided. The imaging system has a multislice detector array and a radiation source configured to emit a radiation beam through the object and towards the multislice detector array. The multislice detector array has a plurality of detector elements arranged in a plurality of detector rows. The method includes scanning the object with the scanning imaging system to acquire a plurality of projection data acquired from a plurality of detector rows including two end rows and a plurality of interior detector rows. The method also includes defining a first plane of reconstruction (POR) for a particular detector row, and defining a second plane of reconstruction (POR) for the particular detector row.

Abstract: The present invention is directed to a method and system for tracking the motion of fluid traveling through a vessel and determining its velocity spectrum from magnetic resonance data collected within a single cycle. The present invention provides a process of independently acquiring and processing MR data from a single cardiac cycle. By combining a SPAMM excitation with a two-dimensional selective excitation, suitable tags of fluid flowing through the vessel may be created. The combination of the excitations produces a sinusoidal variation of transverse magnetization along a column of the fluid. A succession of gradient echoes are then collected to provide information about the flow of fluid in the excited vessel. Each gradient echo undergoes a transformation to obtain a 1-D projection of the excited fluid across the vessel. The magnitudes of the projections are then used to construct a velocity spectrum of the fluid.

Abstract: In order to reduce bias associated with conventional ECG analysis, the present invention provides a method and apparatus to improve diagnosis of acute cardiac syndromes (ACS), such as acute myocardial infarction and acute cardiac ischemia (unstable angina), in specified groups of patients using ECG signals and automatic detection analysis. Specific criteria are developed and utilized based on a prespecified group selection for the particular patient. After identifying group membership for the particular patient, ECG data are acquired from a patient experiencing ACS symptoms. Known criteria typically used for assessing ACS are then modified for the particular group membership. Such criteria significantly reduce the bias found in a baseline group for which the known criteria were established.

Abstract: One aspect of the present invention is a method for multisector computed tomographic (CT) imaging of a cyclically moving object, including steps of: helically scanning a cyclically moving object with a CT imaging system having multiple detector rows and a rotating gantry, at a gantry rotation speed selected either to lead or to lag a cycle of the cyclically moving object; retrospectively gating the projection data of the object with a gating signal related to the motion of the cyclically moving object so that a geometric phase difference is created between a cycle of the rotating gantry and the motion of the cyclically moving object; and reconstructing an image of the cyclically moving object using gated sector data from image data representing a plurality of consecutive cycles of the cyclically moving object.

Abstract: The invention includes a technique for efficient multi-slice fast spin echo image acquisition with black blood contrast in cardiac imaging. The technique includes applying a non-selective inversion pulse, followed by a re-inversion pulse that is slice-selective over a region encompassing a plurality of slice selections. Execution of a series of RF excitation pulses with fast spin echo readout is timed such that signal from blood is near a null point before acquiring data for each spatial slice. For greater contrast consistency, the flip angles for the excitation pulses occurring before the null point can be reduced, and those occurring after the null point can be increased.

Abstract: Degradation in reconstructed medical images is reduced by a method for calibrating a primary decay correction for a radiation detector having a decay curve that can be characterized by a plurality of components having different time constants. The method includes steps of: fitting the decay curve to a sum of a plurality of weighted exponentials having a first set of time constants; applying a correction to a measured response of the detector using a sum of the plurality of weighted exponentials having the first set of time constants to obtain a corrected response; selecting at least one additional exponential time constant dependent upon the corrected response; and fitting the decay curve to a sum of a second plurality of weighted exponentials including the first plurality of time constants and the at least one additional exponential time constant.