Abstract: A method and apparatus-are disclosed for achieving suppression of blood pool signal to detect myocardial infarction using MR technology. An RF pulse sequence is applied that includes a notched inversion RF pulse designed to suppress blood pool in and around a 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: The present invention provides a detector cell having an x-ray absorption component and a thermal sensing component configured to detect thermal differentials in the absorption component resulting from the absorption of x-rays. The absorption component comprises high density materials that respond thermally to the reception of x-rays or other HF electromagnetic energy. The thermal sensing component detects the changes in temperature of the absorption component and outputs electrical signals indicative of the number and intensity of the x-rays absorbed. An image reconstructor then processes those electrical signals to reconstruct an image of the subject scanned. A method of manufacturing the detector cell is also provided.

Abstract: The present invention is directed to a CT imaging system utilizing a pre-subject cone-angle dependent filter to optimize dosage applied to the scan subject for data acquisition. The cone angle dependent pre-subject filter is designed to have a shape that is thicker for outer detector rows and thinner for inner detector rows. As a result, x-rays corresponding to the outer detector rows undergo greater filtering than the x-rays corresponding to the inner detector rows.

Abstract: An imaging tube (51) is provided including a cathode (58) and an anode (60). The cathode (58) includes an emission surface (99), which emits a plurality of electrons along an emission axis (56). The anode (60) includes a body (76) having a track (58) on a peripheral section (78) of the body (76). The plurality of electrons are directed to impinge on the track (58) at an impingement angle &agr; approximately equal to or between 15° and 25° relative to the emission axis (56) and are converted into x-rays. A method of generating x-rays within the imaging tube is also provided.

Abstract: An x-ray tube 10 is provided including an anode mounted to a rotatable shaft positioned within a center bore of a stem element, a bearing assembly positioned between the rotatable shaft and the stem element, and at least one liquid metal shunt in thermal communication with both the rotatable shaft and the stem element, located adjacent to the anode between the anode and the bearing assembly, and directing heat generated at the anode away from the bearing assembly by allowing heat to flow from the rotatable shaft into the stem element prior to heat reaching the bearing assembly.

Abstract: An x-ray imaging system (10) for generating multiple energy x-ray images is provided. The system (10) includes an exposure switch (32) having an “ON”state. A console (14) is electrically coupled to the exposure switch (32) and contains two or more selected imaging program sets. An x-ray generator (18) generates x-rays. An image detector (28) detects the x-rays and generates two or more electronic signals. An image generation controller (20) is electrically coupled to the image detector (28) and controls the sequencing of the two or more electronic signals. An x-ray controller (12) is electrically coupled to the console (14) and the x-ray generator (18). The x-ray controller signals the image generation controller (20) to generate the two or more electronic signals sequentially when the exposure switch (30) is in the ON state and in response to the two or more selected imaging program sets. A method for performing the same is also provided.

Abstract: The present invention is directed to a coil assembly capable of producing a flexible FOV for use with an MRI system. The coil assembly includes a gradient coil disposed about an imaging axis and a plurality of higher order gradient coils, or shim coils, positioned about the primary gradient coil such that the plurality of higher gradient order coils have a radius greater than the radius of the primary gradient coil. A change in the FOV is realized by modulating the current in the higher order gradient coils or shim coils.

Abstract: The present invention is directed to a process and system for removing artifacts resulting from the interactions of a preparation sequence and a gradient echo sequence. A process for suppressing stimulated echoes for spatial preparation sequences without affecting sequence timing or image contrast is disclosed. Stimulated echoes often form when gradient crushers of a preparation sequence are constant in magnitude and direction throughout the imaging sequence. Changing the direction or effective areas of these gradient crushers throughout imaging acquisition prevents stimulated echoes from forming, thereby eliminating ghosting and blurring artifacts. By applying unbalanced gradients or sets of unbalanced gradients between selective RF pulses of an RF pulse sequence, signals attributable to spin transverse magnetization are suppressed resulting in reduced ghosting and/or artifacts.

Abstract: A mobile medical image scanner and teleradiology system are incorporated into an ambulance or other vehicle to permit a patient to be diagnosed while en route to a treatment facility such as a trauma center. The system obtains medical image data while the patient is being transported in the vehicle and transmits the medical image data to a receiver at a location which is remote from the vehicle. At the remote location, the transmitted medical image data is displayed in a humanly discernable manner and interpreted by a qualified physician, who then communicates diagnostic information to the technicians in the vehicle and/or to the treating physicians at the treatment facility. By providing diagnostic information back to the treating physicians prior to the patient's arrival at the treatment facility, the patient can be routed directly to the operating room, or the intensive care unit as necessary, thereby saving valuable time.

Abstract: Passive heat transfer apparatus is provided for an X-ray imaging system used in connection with mammaography, to rapidly conduct heat away from the system X-ray tube. The apparatus comprises a thermally conductive support plate located in the tube housing, in spaced apart relationship with the X-ray tube, and further comprises an elongated device for transferring heat by convection, such as a heat pipe. The heat transfer device has a first end joined to the tube, and a second end joined to the support plate. A quantity of selected working fluid sealably contained in the heat transfer device is disposed to transfer heat along the length thereof, from the tube to the support plate, and cooling fins extending through the housing from the support plate dissipate the heat into the surrounding environment.

Abstract: An object detection apparatus includes a data acquisition system configured to acquire diagnostic data of the subject, an image reconstructor configured to reconstruct at least one image of the subject from the diagnostic data, and a data retrieval device configured to retrieve a first set of bookmarks identifying a first set of objects of interest in the at least one image. The object detection apparatus further includes a computer programmed to display the at least one image on a console and detect input from the user corresponding to a second set of bookmarks identifying a second set of objects of interest in the image. The computer is further programmed to selectively allow the user to incorporate each bookmark of the first set of bookmarks into the second set of bookmarks.

Abstract: The present invention relates generally to MR imaging and, more particularly, to a method and apparatus for reconstructing zoom MR images. An RF coil assembly having a number of detection elements is provided. The RF coil assembly is designed such that the number of detection elements that may be used to acquire imaging data may exceed the number of data acquisition channels of the MR system. Accordingly, the detection elements may be grouped into a number of sets wherein each set transmits acquired data to a specific data acquisition channel to acquire data of a larger region-of-interest (ROI) or, alternately, only one set of detection elements corresponding to a smaller ROI may be activated wherein each detection element of the set transmits data to a data acquisition channel. As a result, a zoom image may be reconstructed.

Abstract: An MRI apparatus and method for minimizing mutual inductance between a center coil and an end coil configuration that reduces wrap-around artifacts in an MR image is provided. The switchable FOV coil configuration includes first and second RF coils aligned along a first axis. The second RF coil is coupled to the first RF coil to form a pair of end saddle coils. A central RF coil is also included having a length along the first axis and positioned at least partially within the end saddle coils such that activation of the central RF coil alone or in combination with the end saddle coils provides differing FOV's for imaging.

Abstract: A method and apparatus are disclosed for creating peripheral MR angiographic images and performing an MRA examination using an intravascular contrast agent in which MR data acquisition is optimized in the most distal stations in a multi-station acquisition. The technique includes administering a contrast agent into the blood stream of the patient, acquiring low spatial resolution MR images of the arterial vasculature, and tracking the passage of the contrast agent through the patient. The patient table is moved in response to the tracking. The technique continues to acquire low spatial resolution images at each of the proximal stations until the most distal station is reached where a high spatial resolution image data set is then acquired of preferentially arterial vascular structures. Higher spatial resolution images are then acquired in the proximal stations.

Abstract: A magnetic resonance imaging (MRI) apparatus and method for micro-imaging is provided. The apparatus comprises an MRI system having a gradient coil positioned within a bore of a magnet that impresses a polarizing magnetic field. The apparatus also includes an RF transceiver system, having an RF switch controlled by a pulse module, to transmit RF signals to an RF coil. Upon selection of a micro-imaging scan, a computer activates a micro-imaging gradient coil positioned within the bore of the magnet. The micro-imaging gradient coils are assembled such that, upon energization, substantially linear magnetic field gradients are created along three axes in a localized FOV adjacent to the micro-imaging gradient coils.

Abstract: The present invention provides a system and method of increasing the sampling rate for MR data acquisition. By implementing ensemble sampling techniques, the present invention provides higher data sampling rates that are useful for several MR data acquisition applications including Echo Planar Imaging, Functional Magnetic Resonance Imaging, and Sensitivity Encoding Imaging (SENSE) techniques. By multiplying an MR signal by a series of pure sinusoids having the same frequency but shifted by an incremental phase, the MR signal may be separated into a number of channels which can be sampled at lower rates by analog-to-digital converters. The output from the converters may then be reconstructed using one of a number of interpolation techniques to create a single digital channel with increased bandwidth. The single channel with increased bandwidth may then be used to acquire MR data with an improved sampling rate.

Abstract: A method and system for providing a ridethrough reserve for a pulse tube refrigerator (PTR) (12) includes a pressurized tank (42) containing a fluid used to provide fluid pressure and auxiliary power to a PTR (12) during an electrical power supply failure. A pressure regulation valve (pressure valve) (44) releases the fluid from the pressurized tank (42) into the PTR (12). A power regulation valve (power valve) releases from the pressurized tank (12) a driving gas volume for driving a pneumatic motor (46). The pneumatic motor (46) in turn drives a rotary valve (22) of the PTR (12). A release valve (50) releases fluid from the PTR (12) so as to lower the fluid pressure to a predetermined pressure range and enable fluid oscillation in the PTR (12).

Abstract: An imaging tube (16) and an apparatus (60) and a method for pre-balancing the imaging tube (16) for use in an imaging system (10) are provided. The imaging tube mass and center of mass are determined. Desired values for the imaging tube mass and imaging tube center of mass are also determined. A mass correction value and a center of mass correction value are calculated in response to the imaging tube mass, the imaging tube center of mass, and the desired values. The imaging tube mass and the imaging tube center of mass are adjusted in response to the mass correction value and the center of mass correction value respectively.

Abstract: A thermal radiation shield 44 and a method for applying the same includes a first coating layer 46, a second coating layer 48, and a thermal shield layer 50. The first coating layer 46 is applied to a first surface. The second coating layer 48 is applied to a second service. The thermal shield layer 50 is positioned between the first coating layer 46 and the second coating layer 48 to form the thermal radiation shield 44. The thermal radiation shield 44 has non-interfering electrical properties.