Abstract: A method and apparatus is disclosed in which a two-tiered approach is taken to first grade a patient to identify the presence of any suspected stenosis, and then a second step is used to acquire more detailed information to grade the stenosis. The invention includes performing a screening study by acquiring a first MR image having a low resolution to scan a suspected stenosis region. After analyzing the first MR image to identify a suspected stenosis within the suspected stenosis region, a more detailed study is performed by acquiring a second MR image having a higher resolution than the first MR image to scan the identified suspected stenosis. If no lesions, or stenotic vessels, are identified after the first MR image, the second MR image need not be obtained.

Abstract: An automatic and adaptive MR data selection technique for use with a multi-receiver coil assembly in an MR imaging device is disclosed. The invention includes acquiring image data from a plurality of receiver coils and determining an index gauge for each of the images. The index gauge is a representation of the position of a given receiver coil within a desired field-of-view (FOV). The index gauges are compared and any image data set having an index gauge demonstrating a less than optimal position of the given receiver coil with respect to the desired FOV is removed based on the index gauges and the comparison. A final image can be reconstructed using the remaining image data sets. The final image is reconstructed from data having overall reduced noise, and therefore reduced artifacts.

Abstract: For the purpose of thoroughly reducing the effect of residual magnetization caused by gradient pulses, the strength of a phase rewinding gradient is made half or about half of that of a phase encoding gradient; the strength of a slice rewinding gradient is made half or about half of that of a slice encoding gradient; a killer gradient having an intensity equal to that of the slice selective gradient is applied to the slice axis; and a killer gradient having an intensity equal to that of a readout gradient is applied to the frequency axis subsequent to the readout gradient.

Abstract: A variable friction disc brake for use with a C-arm x-ray imaging apparatus interposed between the support arm and yoke of the imaging apparatus. The variable friction disc is generally comprised of ring having a gap, width both sides of said gap having apertures therethrough such that a bolt may be inserted into said apertures and used to adjust the width of the gap, and the tension on the ring.

Abstract: Automatic coil selection is based on determining an index gauge for a corresponding k-space data line acquired for each preselected coil during a prescan. Reliance on manual coil selection and markers is eliminated by adaptively determining the coils of an MR system that produce a preferred sensitivity to a desired field-of-view (FOV). The fast scan data is used to determine those coils most sensitive to the FOV and reject coil(s) least sensitive. Using only data acquired with the most sensitive coils, SNR is increased and unwanted artifacts are reduced in the final data acquisition and image reconstruction. Through automatic and adaptive selection/deselection, the invention reduces the susceptibility to human error, and therefore results in higher quality images.

Abstract: For the purpose of obtaining an image without band artifacts, in a pulse sequence for conducting data collection in an SSFP state, the phase of an RF pulse &agr; is adjusted to correct the zeroth-order phase offsets of an FID signal and SE/STE signals and a correction pulse for correcting the first-order phase offsets of the FID signal and the SE/STE signals are incorporated into a read axis pulse.

Abstract: The present invention is directed to a method and apparatus of cardiac CT imaging. The present invention utilizes ECG signals as well as mechanical motion signals of a cardiac region of a subject to correlate CT data acquired of the subject with the phases of the subject's cardiac region. The present invention contemplates measuring mechanical gatings of the heart by measuring changes in pressure, sound, or blood flow acceleration within the cardiac region. The mechanical gatings are then used with ECG data to correlate acquired imaging data with phases of the cardiac region for subsequent image reconstruction.

Abstract: A support arm for use with a C-arm x-ray imaging machine is interposed between the yoke and the cross member of a C-arm x-ray imaging machine. The support arm is a generally rectangular structure having a first end, a second end and a central area between the first end and the second end, a generally circular pin attached to or integrally molded with the first end of the rectangular structure, said pin being set at an obtuse angle relative to the vertical, and a generally circular aperture defined within the second end of the rectangular structure. The support arm also includes a plurality of weight reducing apertures, or pockets, are defined within the support arm and the weight reducing pockets are covered with a plate to prevent contamination. The support arm reduces the overall length of the x-ray apparatus, brings the axis of rotation of the C-arm closer to the center of gravity and saves weight.

Abstract: A finished detector module suitable for use in a computed tomography (CT) imaging system is provided. The finished detector module includes a substrate; a photosensor array mounted on the substrate; an array of scintillators optically coupled to the photosensor array and separated therefrom by a gap filled with either air or a compliant clear film, and a flexible electrical cable electrically coupled to the photosensor array.

Abstract: A method for performing MRI, including imposing N sets of steady-state free precession (SSFP) sequences on an object to be imaged, the sequences including respective initial radio-frequency (RF) excitation pulses, each initial RF excitation pulse having a predetermined phase shift relative to the other initial RF excitation pulses. N is a whole number larger than one and less than six. The method further includes setting the phase shift of the RF pulse of the sequences so that the phase shift of the RF pulse of an Mth sequence is substantially equal to 2 ⁢ π ⁡ ( M - 1 ) N radians, wherein M is a whole number larger than 0 and less than or equal to N, receiving a respective set of image signals from the object responsive to the N sets of SSFP sequences, and processing the set of received image signals to generate an image of the object.

Abstract: In order to provide an aperture position adjusting mechanism in an X-ray CT system with low cost and high accuracy to enable stable reconstruction of X-ray tomographic images, a first shaft (23) is provided with a bore (23a) at a position offset from a center axis, and is rotatably supported by a base plate (20) orthogonally to a pair of rails (21a, 21b). A second shaft (25) is received and is rotatably supported within the bore (23a) through the first shaft (23). The aperture (6) is moved along the rails (21a, 21b) as the second shaft (25) is eccentrically rotated by a motor (7) and, following the eccentric rotation and in a direction opposite to that of the rotation, the first shaft (23) is eccentrically rotated around the center axis of the bore (23a).

Abstract: For the purpose of reducing the numbers of members and molds to reduce the cost of manufacture, and improving grippability in an ultrasonic probe, a fixing member 6 fitted with an ultrasonic element 3, a broad cable 4, a connector 5, and a connection cable 2 is inserted into a mold, and an ultrasonic lens portion 11, a case 12, and a bushing portion 13 are integrally molded by insert molding. Since an ultrasonic probe 10 is made using a single mold, the number of members is reduced, the number of assembly steps is reduced, and reduction in the cost of manufacture can thus be achieved.

Abstract: A method for analyzing a tubular structure in a patient includes receiving a cursor first position within a displayed tubular structure representative of the tubular structure in the patient, determining a path inside the tubular structure based only on the received cursor first position, and moving a cursor along the path by a pre-determined distance in a pre-determined direction to a cursor second position.

Abstract: In order to nullify the adverse effect of an external magnetic field on a static magnetic field generated in an MRI system, small-size coils are used to generate a compensation magnetic field. Thus, the component of the static magnetic field to be applied to a magnetic sensor is canceled. The magnetic sensor can therefore detect the external magnetic field highly precisely. A correction current proportional to the external magnetic field detected highly precisely is fed to BO correction coils. Eventually, the external magnetic field that adversely affects the static magnetic field is canceled.

Abstract: The present invention includes a method and apparatus to correct for gradient field distortions. The invention is particularly applicable in moving table imaging where a single extended image is desirable. The invention includes acquiring MR data in motion in the presence of gradient non-linearities, transforming the MR data acquired into the image domain, and then applying a warping correction function to the transformed MR data. The warp-corrected MR data is then corrected for motion induced during the MR acquisition. The data may be acquired point-by-point, line-by-line, or another sub-portion of the entire MR data acquired, and processed to minimize the amount of motion correction needed. Based on table velocity or acquisition sequence applied, the data is partitioned based on a common motion correction factor, and after correcting for motion, the data is accumulated to build up a final image.

Abstract: In order to arrange continuous wave signal paths using fewer switches, a plurality of amplifying circuits 602 for respectively amplifying a plurality of continuous wave input signals, and outputting each respective pair of amplified signals that have mutually opposite phases for each continuous wave input signal; a plurality of selecting circuits 604, each of which selects one signal of the pair of amplified signals from each of the plurality of amplifying circuits; and a matrix switch 608 employing the output signals from the plurality of selecting circuits as input signals are provided.

Abstract: A programmable, medical imaging system which incorporates algorithms for enhancing the usability of the system for clinicians is described. With respect to programmability, and in one aspect, the present invention relates to a programmable system which includes a learn mode usable for script generation. In the learn mode, a user can rehearse a sequence of actions and save those actions to be replayed later. In another aspect, the present invention is directed to an algorithm which provides a non-blocking, synchronous interface to an underlying asynchronous architecture. Generally, the algorithm decouples the client-server portion of the application from the synchronous development environment. Using this algorithm, a programmer can develop a non-blocking, highly interactive, client-server application without having to resort to asynchronous programming techniques.

Abstract: In order to efficiently obtain projection data having a variety of slice widths (slice patterns) in one scan, an X-ray CT apparatus is provided in which an X-ray tube 40 and an X-ray detector 70 are opposed to each other interposing a subject 100, in which detector a multiplicity of X-ray detector elements are linearly arranged in the channel arrangement direction to form a plurality of rows in the subject body axis direction, for reconstructing a CT tomographic image of the subject based on detected signals from the X-ray detector, wherein the X-ray CT apparatus comprises signal duplicating means 81a for duplicating channel detected signals of the X-ray detector 70 and distributing the duplicated signals to a plurality of groups a, b, etc.; and signal combining means 81b that can combine the distributed duplicated signals in each group in an arbitrary pattern across the detector rows for each channel.

Abstract: To correct motion and magnetic field inhomogeneity phase errors, inverting data collecting read gradients Nr1 and Nr2 are applied to collect correcting data H (n, 1) and H (n, 2) corresponding to focused navigation echoes Ne1 and Ne2, data collecting read gradients r1, . . . , rM which are inverted alternately are applied, and phase encode gradients pdn, p2, . . . , pM are applied at inverting, thereby collecting imaging data F (n, 1), . . . , F (n, M) corresponding to the focused imaging echoes e1, . . . , eM. This sequence is repeated for n=1, . . . , N while changing the magnitude of the phase encode gradient pdn, whereby data F (1, 1) to F (N, M) for filling a k space are collected. Based on the correcting data H (n, 1) and H (n, 2), the imaging data F (n, 1), . . . , F (n, M) are phase corrected.

Abstract: The present invention discloses a method of aligning scintillator crystalline structures for computed tomography imaging and a system of use. Crystal seeds are deposited inside a glass melt and are then grown to form a plurality of layer crystallites. While growing the crystallites, a field is applied to align each crystallite structure in a uniform orientation. As a result, the crystallites are configured to reduce light scattering and improve the overall efficiency of the CT system. A CT system is disclosed implementing a scintillator array having a plurality of scintillators, each scintillator being formed of a plurality of uniformly aligned crystallites. Each crystallite includes a receiving surface and an exiting surface configured perpendicular to an x-ray beam. Further, the receiving surface and the exiting surface are connected by a plurality of surface walls arranged parallel to the x-ray beam.