Abstract: A magnetic resonance imaging apparatus has a main magnet (20) having opposite first and second poles (22, 24) arranged facing one another to define a subject receiving region (14) therebetween. The main magnet (20) generates a main magnetic field (12) within the subject receiving region (14). The main magnetic field (12) has non-uniformities and radial components at the periphery of the subject receiving region (14). A radio frequency coil (74) is disposed about the subject receiving region (14) to transmit radio frequency signals into the subject receiving region (14) and a receiver receives radio frequency signals therefrom. A shielded thrust balanced bi-planar gradient coil assembly (50) is included. The shielded thrust balanced bi-planar gradient coil assembly (50) has at least one pair of windings for generating substantially linear magnetic gradients across the subject receiving region (14).

Abstract: A tool or device for use in interventional MRI has a matrix of electrical conductors formed on or carried by the outer surface of the tool or device so that in use energisation of the conductors can be effect in order to enable the susceptibility of the tool or device to be varied and thus the apparent shape of the tool or device to be varied.

Abstract: Apparatus is disclosed for picking or harvesting agricultural products from plants on which they were grown. The apparatus is especially useful for harvesting peppers of various types (e.g., chili, bell, etc.). The apparatus includes fingers carried on elongated opposing bars which are inclined relative to the ground and are moved through a circular path such that opposing fingers engage and lift the products and separate them from the plants. A trash removal system removes plant stems, leaves and debris. Preferably a hopper is included for receiving and carrying the harvested products until the operator desires to transfer the products to a truck or other carrier. The apparatus is very efficient in harvesting agricultural products and does not crush or damage fragile products or the plants on which the products are grown.

Abstract: In magnetic resonance imaging (MRI) apparatus in which weight considerations and accessibility of the patient result in a magnet 1 with a large bore 2, in order to enable spectroscopy or other activities requiring large magnetic fields to nevertheless be carried out, a small magnet 4 with its own cryostat can be moved from an inoperative position A to an operative position B, in which the large magnet acts as a shield winding for the small magnet.

Abstract: A transformable gamma camera includes detectors mounted for circumferential movement with respect to a rotating gantry. The rotating gantry includes radial bores at desired angular positions about the rotating gantry. The stationary gantry includes a docking station such as a bore. A coupling mechanism allows the detectors to be coupled to the bores in the rotating gantry or to the docking station. Each of the detectors is movable radially with respect to the rotating gantry's axis of rotation and tangentially to the imaging region. The gamma camera is readily transformable between 120 degree, orthogonal, and opposed detector configurations; a plurality of aperture sizes can also be defined.

Abstract: A nuclear camera system includes oppositely disposed radiation detectors (10a, 10b) which view an examination region 14 wherein a subject 16 is received therein. During a diagnostic scan, a motor and drive assembly (18) concurrently moves the detectors (10a, 10b) in a straight path along a longitudinal axis (20) for a selected time interval. The radiation detectors (10a, 10b) are positioned at a first angle at which the subject is viewed and the angle is maintained through the scan. A data processor (23) collects the data from the detected radiation and a coincidence circuitry (26) determines coincidence radiation events occurring on the detectors 10a, 10b. A first set of image data is generated for the first angular view and stored in a view memory (28). A second scan is performed where the detectors (10a, 10b) are shifted to a second angular view and the detectors are moved along the longitudinal axis for a second selected time interval.

Abstract: An imaging device includes a support member (30), a x-ray source (32) mounted to the support member via a first arm (34), and an x-ray detector (36) mounted to the support member via a second arm (38). The x-ray detector includes a sealed housing (72) mounted to the second arm and a flat panel image receptor (74) retained within the housing. A cooling system (G) exchanges heated air in the housing with ambient air located remote from the housing. The support member (30) includes an open channel (68), a closed channel (70), a common wall (106) separating the open channel from the closed channel, and a series of vents (108) through the common wall. The second arm (38) includes an inlet passage (92) and an exhaust passage (90) each of which communicate with the closed passage (70) and interior cavity (98) of the housing. At least one fan (100) is positioned in at least one of the exhaust passage and the inlet passage.

Abstract: A method (100) of automatically tuning a radio frequency transmitter (24) and receiver (38) in a magnetic resonance imaging apparatus to an optimum frequency includes generating and acquiring (104) a magnetic resonance signal. The magnetic resonance signal is transformed to the frequency domain and spectral magnitude of the signal is computed (106). A center of gravity interpolation is performed (110) on the spectral magnitude to obtain a desired frequency sampling. A model function is generated based upon a strength of a main magnetic field which has peaks separated by the same separation as that for fat and water signals. The spectral magnitude is correlated (112) with the model function and a peak having the greatest magnitude is located therefrom. The location of a species peak along the spectral magnitude is estimated (114) from empirically derived information, the strength of the main magnetic field and the location of the correlation peak.

Abstract: A surgical guide for use with an image guided surgery includes first and second surfaces. At least three signaling devices such as infrared emitters are disposed on the first surface, and a cylindrical mounting boss is disposed on the second surface. A guide aperture is perpendicular to the first and second surfaces and extends between them. The guide aperture is configured to support a surgical tool such as a biopsy needle. A sleeve may be placed in the aperture to support additional tools.

Abstract: A method and coil arrangement for use in magnetic resonance imaging facilitates the examination of a localized region of the body. A plurality of substantially identical saddle coils are disposed about a former. The coils, which define a generally cylindrical volume, overlap one another in a circumferential direction. In one embodiment, a generally planar rectangular coil intersects the cylindrical volume. The method and coil arrangement are particularly well suited to imaging a region adjacent but outside the cylindrical volume. The coil arrangement is also well suited to insertion within the body, especially the rectum.

Abstract: An MR compatible endoscope 1 has associated MR saddle coil 10 mounted on a removeable former 9. The tip 2 of the endoscope has the usual service channels for imaging. The coil 10 provides an additional MR signal. To avoid the need to plug the coil 10 in, it is inductively couples to a pick-up coil 13 and, to enable this to be removable as will from the endoscope, this may be located in one of the service channels 7 of the endoscope. The removable nature of the coil permits easy repair and, more importantly, a range of coils to be fitted to the endoscope to accommodate different magnetic field strengths.

Abstract: A detector assembly for x-ray image acquisition includes a flat panel detector array. The detector assembly also includes a rechargeable battery, an analog to digital converter, and an image memory. The battery provides electrical power to the detector assembly so that image data may be acquired without using a power source external to the assembly. The image data is stored in a memory. The detector is subsequently be connected to a docking station which includes a battery charger. The image data is downloaded, and the battery is recharged.

Abstract: After exciting dipoles in an examination region (60), a train of magnetic resonance echoes including echoes (66.sub.1, 66.sub.2, . . . ) is induced, e.g., with a series of refocusing pulses including pulses (68.sub.1, 68.sub.2, . . . ). The echoes are phase and frequency-encoded. A receiver 38 is gated by a gate circuit (82) to sample the even echoes (66.sub.2 -66.sub.10) and the odd echoes (66.sub.5 -66.sub.10) that occur after a threshold odd echo such as the third echo (66.sub.3) so as to generate an image of a common physical region which exhibits reduced motion artifacts.

Abstract: A radiation source which generates a radiation cone-beam (14) and a two-dimensional radiation detector are spiralled continuously around and longitudinally relative to an imaging volume. Image data from the two-dimensional display is reconstructed (30.sub.1, 30.sub.2, . . . 30.sub.n) into a volumetric, physiological image stored in a subject memory (32). During an interventional surgical procedure with a surgical instrument (42), the x-ray source is gated to operate intermittently, e.g., at 60.degree. angular intervals, at a reduced radiation intensity by an x-ray tube control (40). The additional data is reconstructed into a three-dimensional image representation of the surgical instrument and stored in an instrument memory (34). An operator image selection processor (60) causes data retrieval circuits (62a, 62b) to retrieve like slices or other image representations from the subject and instrument memories.

Abstract: A transformable gamma camera includes detectors mounted for circumferential movement with respect to a rotating gantry. The rotating gantry includes radial bores at desired angular positions about the rotating gantry. The stationary gantry includes a docking station such as a bore. A coupling mechanism allows the detectors to be coupled to the bores in the rotating gantry or to the docking station. Each of the detectors is movable radially with respect to the rotating gantry's axis of rotation and tangentially to the imaging region. The gamma camera is readily transformable between 120 degree, orthogonal, and opposed detector configurations; a plurality of aperture sizes can also be defined.

Abstract: A gamma camera system includes two or more radiation detector heads and which are mounted opposite each other to a gantry for rotation about a subject. A transmission radiation source assembly is mounted to the front face of at least one of the detectors and can be moved across the face of the detector. The source assembly includes a radiation attenuating housing, a leaded bronze source holder, and a radionuclide source. The radionuclide source is retained in a longitudinal groove disposed in the source holder. The source holder may be rotated into open, closed, and access positions. The transmission radiation emitted by the source assembly is directed across the examination region, attenuated by the subject, and detected by the opposed detector. The gamma camera system also includes a filter which selectively attenuates the transmission radiation based on the attenuation profile of the object so as to prevent saturation of the opposed detector.

Abstract: Within a selected slice or slab, diffusion sensitizing gradients (54, 56) and read gradients (66, 68) are induced along each of a pair of orthogonal axes (G.sub.x, G.sub.y). The motion sensitizing gradient pulses sensitize excited magnetic resonance to diffusion in a preselected diffusion direction (D) which is orthogonal to a selected read gradient direction. The diffusion sensitizing gradients are rotated by sin(.theta.+.pi./2) and cos(.theta.+.pi./2) and the read gradients are rotated by sin.theta. and cos.theta. to generate a plurality of angularly displaced data lines. The diffusion sensitivity direction remains perpendicular to the read direction in each of the angularly displaced data lines. The phase of each data line is determined (90) and shifted (94) to compensate for linear translations. The data values within each data line are shifted (86) to center the peak amplitude of the data line at a preselected position to compensate for higher order motion.

Abstract: A plurality of radio frequency excitation pulses or shots (52) are applied, ten in the embodiment illustrated in FIGS. 4 and 5. Following each shot, sets of data lines are collected. In the first set, an early gradient echo (EGE1), a spin echo (SE1), and a late gradient echo (LGE1), are induced to form three corresponding data lines. Magnetization is inverted (56) and a second set of data lines are generated. In the illustrated embodiment, nine sets of data lines are generated in each repetition. Phase-encoding gradient pulses (86, 88) are applied to cause the early gradient echo, the spin echo, and the late gradient echo data lines of each set to fall offset by a third of k-space. Phase-encoding pulses (74) are applied before each set and stepped such that in half of the repetitions, the phase-encoding increases with each subsequent set. In the other half of the repetitions, the phase-encoding decreases for each subsequent set.

Abstract: An imaging system produces an image of an internal part of an object and a representation of a tool, which representation corresponds to the position of the tool with respect to the actual object. An imaging apparatus defines an examination region. After an image of the object is obtained, the object is moved to a treatment position fixed in relation to the examination region. The object is supported on a moveable table, which is in turn supported on a pair of rails. A reference frame mounted to the imaging apparatus carries radiation detectors for detecting radiation emitted by emitters on a surgical tool. The position of the tool with respect to the reference frame, and hence with respect to the actual object, can therefore be determined.

Abstract: Mode selection switches (76, 96, 98) selectively interconnect a sensor line shift timing generator (76) with one of three signal sources - (1) a conventional raster scan timing signal from a raster scan sync generator (70), (2) variable speed external timing signals from a tachometer (32), and (3) fixed speed timing signals developed from the horizontal timing signals of the raster scan sync generator. In a time delay and integration mode, the sensor line shift timing generator causes the CCD arrays of an image section (22) and storage section (24) to shift pixel values down the CCD arrays at a rate commensurate with the external timing signal. As a spot of light emanating from a portion of an object moving through an examination region moves along the CCD array, a corresponding pixel charge is shifted through the CCD array at the same speed such that the same pixel charge integrates light from the same spot as it moves the entire length of the CCD array.