Abstract: An anode assembly (14) is mounted by a bearing assembly (20-28) in a bearing housing (30). The bearing housing is constructed of substantially pure copper or other high thermal conductivity metal. The bearing housing defines a shoulder portion (36) between a side wall (34) and a mounting shank (38). The mounting shank is threaded (66) to be clamped into a mounting assembly (60) which provides substantially the sole support for the bearing and anode assembly. A steel reinforcing collar (52) with an integral seat portion (54) supports the shank and shoulder portions of the bearing housing. A vacuum envelope (40) of the x-ray tube includes a metal cap portion (44) which is sealed between the seat and shoulder portions in a vacuum tight relationship.

Abstract: During surgery, a physician speaks commands that are received by a microphone (10). A speech processor (12) converts audio signals from the microphone into word signals. A command interpreter (14) compares each word signal with a list of previously authorized command words. When the word signal corresponds to one of the preselected command words, a corresponding command signal is generated and sent to a volume imager (18), a video recorder (20), a hard copy, printer (28), or other system component. The volume imager generates an image representation signal indicative of a portion of image data stored therein which is displayed on a video monitor (B) or recorded on the video recorder.

Abstract: Pixel values f(m,n) of an image are reduced (A) by predicting each pixel value based on preceding pixel values and retaining the deviation e(m,n) between the actual and predicted values. The reduced values e(m,n) are serially fed to an input latch (20). A latched sizer (22) determines the larger of the number of bits of the value in the input latch and the largest previously received reduced value e(m,n). A comparator (42) compares a number of bits from the latched sizer with the number of bits per field indicated by a look-up table (44). Each time another reduced value e(m,n) is received, a state counter (46) indexes one state, i.e., increases the number of bit fields per output word and, when necessary causes the look-up table (44) to reduce the number of bits per field.

Abstract: A multi-mode acquisition x-ray imaging system (A) provides a unified apparatus and method to acquire valid x-ray video images including the last image of a run, and to display these images flicker-free on an image monitor (50). A beam blanking signal (54) synchronizes operation of a TV camera (48) and TV camera controller (56), so all image data or frames acquired in any acquisition mode including one having a pulse exposure rate or an asynchronous pulse exposure rate is acquired and processed by a digital imaging system (40). The image data is stored in a dual buffered storage (76) which alternatingly connects a first buffer (80a) and a second buffer (80b) to the image monitor (50). When the exposure rate is changed, transition logic (84) determines whether images, exposed during the transition to another exposure rate are under or overexposed.

Abstract: A CT scanner has an x-ray tube (B) which is carried by a rotating gantry portion around a patient receiving region (12). A large diameter, annular radiator (30) is connected to the rotating gantry for rotation with the x-ray tube. A cooling oil is circulated around the x-ray tube and through passages (32, 74, 100) of the rotating radiator. An annular stationary member is mounted to a stationary gantry portion (A) of the CT scanner. In the embodiment of FIGS. 2 and 3, the stationary member is an annular tube (36) which substantially surrounds the rotating radiator except for an annular access aperture (38). Spray jets (40) spray the rotating radiator with water which is drained (42), circulated to a remote heat exchange or cooling apparatus (D), and recirculated to the spray nozzles. Baffles (52, 54), gutters (58), lip and baffle arrangements (54, 56), and the like, inhibit the sprayed water from escaping from the tube (36). In the embodiment of FIG. 4, the water is sprayed on a wick member (76).

Abstract: A magnetic resonance imaging apparatus (A) applies appropriate magnetic fields, magnetic field gradients, and radio frequency pulses across an examination region to generate magnetic resonance signals or views indicative of the properties of a volume of a subject examined in the examination region. The views are reconstructed (B) into voxel values V(x,y,z) and stored in a volumetric image memory (C). A relative angle and position of a viewing plane (10) relative to the image volume are selected. A plurality of rays (14), each corresponding to a pixel P(i,j) of a resultant projection image, are projected from the viewing plane into the volumetric image data. Each ray retrieves a corresponding vector of voxel values V.sub.1, V.sub.2, V.sub.3, . . . V.sub.n. Bright voxel values indicate blood. Dark pixel values indicate non-blood tissue. Intermediate voxel values have a greater uncertainty whether the pixel value represents blood or non-blood tissue.

Abstract: A magnetic resonance imaging system (A) examines a region of a patient and generates a plurality of views which are reconstructed (B) into a volumetric image representation and stored in a volume image memory (C). A ray projector (D) projects a plurality of rays (14) from a selectable viewing plane (10) into the volume data and retrieves a plurality of data values that lie along each ray. A maximum intensity projection system (E) selects the brightest pixel along each ray to become the corresponding pixel value of an uncorrected projection angiographic image which is stored in an image memory (F). The uncorrected angiographic image represents blood as bright or white values and non-blood tissues as dark or black values. Noise, some tissue types, regions with fine capillaries, and the like, cause the background non-blood regions of the image to appear hazy or gray rather than black.

Abstract: A C.T. scanner (A) or other medical diagnostic imager generates volume image data which is stored in an image memory (B). An image memory access controller (30) withdraws selected pixel values from the volume image memory which it provides a video processor (20) to formulate the appropriate video signals for display on a video monitor (C). An operator defines a volume on an operator controller (32). A plurality of interconnected polygons define the three-dimensional volume specified by the operator. The video processor converts these defined polygons into an appropriate display on the monitor. The polygons are selected to define a subregion to be viewed. The polygons are rotated about one or more of (x), (y), and (z) axis, scaled, and translated along these axis to select an orientation from which the polygon and enclosed data is to be viewed. The rotation, scaling and translation is stored (38, 40, 42).

Abstract: A head (10) of a nuclear medicine camera has a face defined by scintillation crystal (12) which is non-rectangular. In particular, it has symmetrically clipped corners (16). As the head scans from an initial position (32) to a final position (34), radiation originating from regions (72) and (82) are received by the detector head for a shorter duration than radiation from a corresponding point in the central region, due to the clipped corners. Particularly, for a path (74) that is shorter by 2W.sub.1 than a width W.sub.0 of the central portion, 2W.sub.1 /W.sub.0 fewer counts are received in region (82) from a radiation source of the same strength than would have been received in the central region. An edge enhancement circuit (70 ) boosts the number of radiation events counted in an image memory (54) in pixels corresponding to region (72) by 2W.sub.i /W.sub.0 and in region (82) by W.sub.i /W.sub.0.

Abstract: A superconducting magnetic imaging apparatus includes a vacuum vessel (40) having a central helium reservoir (48) in which superconducting magnetic coil windings (44) are maintained at a superconducting temperature. The vacuum vessel defines an internal bore (42) within which a self-shielded gradient coil assembly (14) and an RF coil (22) are received. The self-shielded coil assembly includes an inner former (60) which defines an imaging region (12) within which an imaged portion of the patient are received. X and y-gradient coils having winding patterns (62) are bonded to the former (60) forming an integral structure. A z-gradient coil (70) is mounted to mechanical reinforcement structure (72) to be held in a spaced relationship from the x and y-gradient coils with an air gap (74) in between. This facilitates the dissipation of heat generated by the large current pulses applied to the x and y-gradient coils.

Abstract: A magnetic resonance imaging apparatus defines an examination region (14) within which main magnets (10) create a uniform magnetic field. Magnetic resonance is excited in dipoles of a subject within the examination region causing the generation of magnetic resonance signals which are received by a localized coil (C). Because the localized coil is disposed within the examination region, the localized coil, particularly a magnetic resonance processing circuit (54) mounted on the coil is free of ferrous materials, such as iron and nickel, to prevent distortion of the uniform magnetic field. The circuit includes an array of component dice which are free of ferrous or other packaging. The dice are adhesively bonded to a substrate (62) and connected by whiskers (82) with electrically conductive lead lines (60) on the substrate. In one embodiment, the component dice include a transistor (Q1) and other circuit components for amplifying the received resonance signal.

Abstract: A medical diagnostic imager (10) reconstructs (96) raw scan data into digital image representations which are stored in a mass storage memory (46) such as DRAM or disk. As the scanner reconstructs the series of images, each digital representation image is transferred to an image VRAM (100) into one of a plurality of selected image areas. A video monitor (24) displays the electronic image representations from the image VRAM in the selected pattern of images, e.g. a 4.times.3 grid of images. The digital image representations are transferred to the image VRAM and displayed on the video monitor as they are generated such that the monitor displays the previously generated images and the most recently generated image as it develops during the reconstruction process. The diagnosing physician selects (104) one of the images and selectively adjusts (110) the window and level of its gray scale.

Abstract: An evacuated envelope (C) which is connected with an anode (A), has a cathode assembly (B) rotatably mounted inside. Magnets (44, 46) hold the cathode assembly stationary as the anode and envelope rotate. A ferrite core transformer (60) includes a ferrite core primary (66) stationarily mounted exterior to the envelope. A secondary (64) is mounted to the cathode assembly interior to the envelope. The secondary winding includes a ferrite core (70), a portion of which is surrounded by a ceramic, dielectric bobbin (76). The bobbin includes walls or ridges (78) which define a spiral groove (80) therearound in which an uninsulated electric wire (82) is received. The uninsulated electric wire is connected with a cathode filament (52). The primary winding has a ferrite core (90) that has about five times the cross section as the secondary ferrite core to compensate for a low, about 20%, coupling efficiency between the primary and secondary windings.

Abstract: An examination region (12) is defined within the bore of a superconducting magnet assembly (10). An RF coil (22) and gradient magnetic field coils (14) are disposed within the bore of the superconducting magnet assembly around the examination region. The superconducting magnet includes a hollow, cylindrical vacuum vessel (40). An annular, liquid helium holding low temperature reservoir (60) extends centrally through the vacuum vessel, but is sealed therefrom such that liquid helium is not drawn into the vacuum. A plurality of annular superconducting magnets (56) are received in the low temperature reservoir immersed in the liquid helium. A first cold shield (44) and a second cold shield (50) are mounted in the vacuum vessel surrounding the low temperature reservoir. A main magnetic field shield coil (66) is disposed in the low temperature reservoir outside of the annular superconducting magnets for canceling the magnetic field generated by the annular magnets surrounding the magnet.

Abstract: A CT scanner or other medical diagnostic imager (A) generates data which is reconstructed (B) into a three-dimensional image representation that is stored in an image memory (C). Points on a surface (10) of a selected subregion, such as the surface of an internal organ, in the three-dimensional image representation are determined (12) which are visible from and correspond to pixels on a viewing plane (14). For each viewable point on the surface, a mean variation along an x, y, and z-coordinate system with its origin at the surface point in question is determined (20). A covariance matrix whose matrix elements along the diagonal are indicative of a rate of variance along each axis and whose other matrix values are indicative of a rate of variance relative to pairs of axes is defined (20). A rate of most rapid change through the 3D data is determined (22), by eigenvalue decomposition (24) of the covariance matrix. A vector along the rate of most rapid change is normalized (26).

Abstract: A superconducting magnet (10) generates a uniform, static magnetic field through a central bore (12) along its longitudinal or z-axis. A biplanar gradient coil assembly (44) is inserted into the bore to create gradients across the static magnetic field along orthogonal x, y, and z-axes. A biplanar radio frequency coil assembly (50, 80) is inserted into the bore for transmitting radio frequency signals into a subject and receiving magnetic resonance signals from the subject. The radio frequency coil includes a first biplanar coil assembly (50) for generating RF signals in an x-direction and a second biplanar coil assembly (80) for generating RF signals in a y-direction. The two biplanar coil assemblies each include a plurality of conductors (52, 82) along a first plane and a second plurality of conductors (54, 84) along a parallel second plane. The conductors extend parallel to the z-direction.

Abstract: An examination region (12) is defined within the bore of a superconducting magnet assembly (10). An RF coil (22) and gradient magnetic field coils (14) are disposed within the bore of the superconducting magnetic assembly around the examination region. The superconducting magnet includes a hollow, tubular vacuum vessel (40) which contains a plurality of annular superconducting magnets (58). These superconducting magnets are held in a liquid helium holding reservoir (60) such that they are held below their superconducting temperature. A first cold shield (44) and a second cold shield (50 ) have tubular portions between the superconducting magnets and the examination region. These cylindrical portions each include a cylinder (70) of a electrically insulating material such as reinforced plastic. Thermally conductive layers (72) are defined on each surface and are divided by etched slots or resistance portions (74) into a multiplicity of elongated narrow segments (92).

Abstract: A one piece self-supporting collapsible plastic urology drain bag 24 is mounted to an examination end 14 of a urology table 10. The pan includes a vertical inner end wall 28, a sloping outer end wall 34, a pair of opposite side wall 30, 32, and a bottom wall 36 through which a drain port 38 is defined. The inner end wall 28 of the drain pan is secured between plates 50 and 52. The drain bag is sufficiently flexible to allow a physician to collapse the outer end wall 34 against inner end wall 28 yet with sufficient plastic memory to enable the drain pan to return to its non-flexed position when the collapsing force is removed. A retaining means 56 is disposed on each end of the upper edge of plate 52. Each retaining means comprises a support means 58 and pin 60 arrangement.

Abstract: An examination region (12) is defined along a z-axis offset from a geometric center (30) of a gradient coil assembly (20). Cylinders of a non-conductive, non-magnetic material support x, y, and z-gradient coils (24, 26, 22) for causing orthogonal magnetic field gradients through the offset examination region. The z-gradient coil (FIG. 2 ) includes a plurality of distributed loop arrays with a winding pattern selected to cause a region of linear magnetic field gradients in the z-direction in a region offset toward a cylinder first end (32). The x and y-gradient coils each include two pairs of oppositely disposed windings (FIG. 3 ) which include a pair of inner spirals (96, 98) offset towards the first end of the cylinder and an outer spiral (90) extending therearound. The outer spiral bows in (92) toward the cylinder first end and fans out (94) toward the second end.