Abstract: A method and apparatus are provided for reconstructing list mode data acquired during a positron emission tomography scan of an object, the data including information indicative of a plurality of detected positron annihilation events. Detected events occurring in a region of interest are identified; the identified events are reconstructed using an iterative reconstruction technique which includes a ray tracing operation to generate volumetric data indicative of the region of interest, wherein the ray tracing operation traces only image matrix elements located in the region of interest; and a human readable image indicative of the volumetric data is generated. In another aspect an image mask and a projection mask are defined correlating to the region of interest; image matrix elements located in the region of interest are determined by applying the image mask; and detected events occurring in a region of interest are identified by applying the projection mask.

Abstract: A hybrid imaging system includes a magnetic resonance scanner and a second modality imaging system disposed in the same radio frequency isolation space. The second modality imaging system includes radiation detectors configured to detect at least one of high energy particles and high energy photons. In some embodiments a retractable radio frequency screen is selectively extendible into a gap between the magnetic resonance scanner and the second modality imaging system. In some embodiments shim coils are disposed with the magnetic resonance scanner and are configured to compensate for distortion of the static magnetic field of the magnetic resonance scanner produced by proximity of the second modality imaging system.

Abstract: A method and system for use in positron emission tomography, wherein a list-based reconstructor means (129) is configured to generate first portion volumetric data responsive to a first portion of a plurality of positron annihilation events detected during a positron emission tomography scan; generate a human-readable image indicative of the first portion volumetric data; use a list-based reconstruction technique to generate composite volumetric data responsive to the first portion volumetric data and a second portion of the plurality of positron annihilation events; and generate a composite human-readable image indicative of the composite volumetric data. In another aspect the reconstructor (129) is configured to selecting first or second portion event quantities responsive to one or more parameters including image definition requirements and processing time requirements.

Abstract: A method and system for use in positron emission tomography, wherein a first processor element (234) is configured to reconstruct a plurality of positron annihilation events detected during a positron emission tomography scan using a list-based reconstruction technique to generate first volumetric data. A second reconstructor (226) is configured to reconstruct the plurality of events using a second reconstruction technique to generate second volumetric data for determining an error correction (228), the error correction applied to the first volumetric data to generate corrected volumetric data for generating a human-readable image (234). In one embodiment a multiplicative error correction is performed on the plurality of events, the first processor element (234) reconstructing the corrected plurality of events; and the second volumetric data error correction comprises an additive error correction.

Abstract: A system reverses degraded energy resolution of semiconductor radiation detection elements (44) which are used in a radiation detector assembly. A means (38) identifies semiconductor elements which exhibit degraded energy resolution as compared to an initial level of energy resolution after application of the forward bias. A means (40) restores the degraded semiconductor elements to the initial level of energy resolution by applying the reverse bias. A heater (74) accelerates the restoration process by supplying an elevated ambient temperature. A screening means (48) screens new semiconductor elements to identify the elements which are susceptible to degradation. A forward bias is applied by a forward bias means (50) to induce the degradation. A heater (52) increases an ambient temperature to accelerate the performance degradation in the new semiconductor elements. The identified degradable elements are treated with a reverse bias prior to installation in the detector.

Abstract: A nuclear camera (10) includes four or more gamma detectors (20, 20?, 20?, 201, 202, 203, 204, 205, 206) arranged or, a generally circular rotatable gantry (12, 12?, 12?, 12??) around an imaging region that emits emission radiation. The gamma detectors are each disposed at a fixed equal distance (R, R2, R3, R5) from an imaging isocenter (22, 22?, 22?, 22??) to rotate in a fixed radius circular orbit. Each gamma detector includes a radiation sensitive surface (72) that responds to the emission radiation and a slat collimator (70) that spins about an axis 88. Resolution and sensitivity at the fixed radius are selected by selecting collimator slat height (Wz) and spacing (G) and radiation sensitive surface width (Cy). The gamma detectors and rotating gantry are enclosed in an optically opaque toroidal housing (14) that defines a generally circular bore (16) that admits imaging subjects over a range of sizes.

Abstract: A PET system includes an improved image reconstruction algorithm based on an improved modeling of the point-spread function. PET time of flight data is used to obtain a mean emitting point and a time of flight probability function. This information is then used to model the point-spread function. The time of flight probability function and the detector response function are used to define a probability volume for a given line of response, which is then used in the reconstruction of the image.

Abstract: An apparatus for varying nip pressure in a media feedpath including a feed roller and a pressure roller defining a feed nip there between includes a rotatable cam having a preselected eccentric path when rotated, a first pivotable linkage pivotally engaging the rotatable cam, a second pivotable linkage, a biasing member operably interconnecting the first and second pivotal linkages for providing a biasing force on the pressure roller. The pressure roller is rotatably connected to the second linkage opposite the biasing member, wherein rotation of the cam varies the biasing force provided by the biasing member on the pressure roller.

Abstract: A PET system includes an improved image reconstruction algorithm based on an improved modeling of the point-spread function. PET time of flight data is used to obtain a mean emitting point and a time of flight probability function. This information is then used to model the point-spread function. The time of flight probability function and the detector response function are used to define a probability volume for a given line of response, which is then used in the reconstruction of the image.

Abstract: A media edge guide assembly for use in an imaging apparatus having a media supply source includes a first edge guide portion and a second edge guide portion. The first edge guide portion and the second edge guide portion are arranged to have an axis of rotation passing through the first edge guide portion and the second edge guide portion. The first edge guide portion and the second edge guide portion are laterally interconnected to facilitate movement as a unit in a lateral direction along the axis of rotation, and the first edge guide portion and the second edge guide portion are configured to be rotationally disconnected with respect to the axis of rotation to permit the first edge guide portion to rotate around the axis of rotation independent of the second edge guide portion.

Abstract: A system reverses degraded energy resolution of semiconductor radiation detection elements (44) which are used in a radiation detector assembly. A means (38) identifies semiconductor elements which exhibit degraded energy resolution as compared to an initial level of energy resolution after application of the forward bias. A means (40) restores the degraded semiconductor elements to the initial level of energy resolution by applying the reverse bias. A heater (74) accelerates the restoration process by supplying an elevated ambient temperature. A screening means (48) screens new semiconductor elements to identify the elements which are susceptible to degradation. A forward bias is applied by a forward bias means (50) to induce the degradation. A heater (52) increases an ambient temperature to accelerate the performance degradation in the new semiconductor elements. The identified degradable elements are treated with a reverse bias prior to installation in the detector.

Abstract: An apparatus for treating an aqueous medium containing microorganisms comprises an intake for receiving the aqueous medium containing microorganisms. A pressure differential inducer is associated to the intake so as to receive the aqueous medium containing microorganisms with a desired level of gas saturation. The pressure differential inducer is actuatable to expose the aqueous medium containing microorganisms with a desired level of gas saturation to accelerations so as to cause cell wall rupture of the microorganisms. An outlet is associated with the pressure differential inducer for outletting the treated aqueous medium containing ruptured microorganism cells and contents. The treated aqueous medium containing ruptured cell wall of the microorganisms is disposed of and/or recycled.

Abstract: A nuclear camera (10) includes four or more gamma detectors (20, 20?, 20?, 201, 202, 203, 204, 205, 206) arranged or, a generally circular rotatable gantry (12, 12?, 12?, 12??) around an imaging region that emits emission radiation. The gamma detectors are each disposed at a fixed equal distance (R, R2, R3, R5) from an imaging isocenter (22, 22?, 22?, 22?) to rotate in a fixed radius circular orbit. Each gamma detector includes a radiation sensitive surface (72) that responds to the emission radiation and a slat collimator (70) that spins about an axis 88. Resolution and sensitivity at the fixed radius are selected by selecting collimator slat height (Wz) and spacing (G) and radiation sensitive surface width (Cy). The gamma detectors and rotating gantry are enclosed in an optically opaque toroidal housing (14) that defines a generally circular bore (16) that admits imaging subjects over a range of sizes.

Abstract: An imaging apparatus includes a sheet picking mechanism drive unit that includes a sheet pick gear train for driving a sheet picking mechanism to transport a sheet from a stack of print media along the sheet feed path. A print media dam is pivotably coupled at an axis to the imaging apparatus. The print media dam has at least one dam member and a first gear. Each dam member has a media engaging surface. A drive mechanism is drivably coupled between the sheet picking drive mechanism and the first gear to move the dam member between an extended position and a retracted position. When the dam member is in the extended position, the media engaging surface is positioned to interrupt the sheet feed path. When the dam member is in the retracted position, the media engaging surface is positioned to not interrupt the sheet feed path.

Abstract: A power supply keying method for use with an electrical apparatus includes defining a plurality of power supply classes; associating with the plurality of power supply classes a plurality of power supplies, each of the plurality of power supplies including a power supply housing having a unique keying arrangement corresponding to one power supply class of the plurality of power supply classes; and providing in the electrical apparatus a power supply receptacle for receiving at least one power supply of the plurality of power supplies, the unique keying arrangement of the power supply housing in conjunction with the power supply receptacle permitting reception of a particular power supply of the plurality of power supplies into the power supply receptacle only if the power supply class associated with the particular power supply has power supply electrical characteristics that satisfy electrical power requirements of the electrical apparatus.

Abstract: A packaging structure for supporting a segment of optical fiber provided with a wavelength filter optically coupled thereto. The wavelength filter defines a temperature dependent center wavelength and a rate of wavelength drift per temperature change. The optical fiber is attachable about a fiber fast first attachment point and a fiber second attachment point to a housing having a generally hollow housing body for protecting the wavelength filter. The structure allows for both adjustment of the center wavelength and also for adjustment of the rate of wavelength drift per temperature change independently from the adjustment of the center wavelength. The wavelength excursion is typically adjusted by adjusting the spacing between the fiber first and second adjustment points. The center wavelength is typically independently adjusted by adjusting the tension imparted on the wavelength filter when the fiber is attached to the housing.

Abstract: A packaging structure for supporting a segment of optical fiber provided with a wavelength filter optically coupled thereto. The wavelength filter defines a temperature dependent center wavelength and a rate of wavelength drift per temperature change. The optical fiber is attachable about a fiber first attachment point and a fiber second attachment point to a housing having a generally hollow housing body for protecting the wavelength filter. The structure allows for both adjustment of the center wavelength and also for adjustment of the rate of wavelength drift per temperature change independently from the adjustment of the center wavelength. The wavelength excursion is typically adjusted by adjusting the spacing between the fiber first and second adjustment points. The center wavelength is typically independently adjusted by adjusting the tension imparted on the wavelength filter when the fiber is attached to the housing.

Abstract: A gamma camera includes a plurality of detectors (32, 34) for detecting emission radiation emitted from within a subject and transmission radiation which has traversed a subject to be imaged, the subject attenuating the radiation. Each detector generates position and energy data. At least one transmission radiation source (54, 54′) transmits transmission radiation through an examination region (36) to a first segment (74, 74′) of the opposite detector. In one embodiment, segment selector circuitry (88) connected with the detectors selectively disables a portion of each detector head during collection of emission data, transmission data, or both. In another embodiment, transmission radiation is received by the first segment (74, 74′) simultaneously with emission radiation being received by a second segment (72, 72′) of each detector. The first segment is uncollimated or collimated for the transmission radiation source.

Abstract: A nuclear imaging apparatus includes a radiation detector comprising an array (18) of solid state detector elements (22) responsive to incident gamma radiation by emitting a current spike. A pixel correction processor (44) detects defective detector elements in the array and a flood correction circuit (66) corrects detected radiation events (70) based on sensitivity differences between a plurality of groupings of detector elements in the array. A reconstruction processor (76) reconstructs an image representation from the corrected radiation events (74).

Abstract: &ggr;-ray emissions (14) are detected by a rotating, one-dimensional detector array (18). Slats of a convergent or divergent collimator (16) are mounted between detector elements. The slats are canted by an angle &agr; from focusing on a focal spot (40) on a perpendicular bisector to the detector array. As a detector head (30) revolves around a longitudinal axis (36) of the subject, the head is canted (FIG. 5) to generate angularly offset data sets. Data sets with the detector array rotated to 180° opposite orientations are processed (62) to generate a first derivative data set. Parallel lines or planes (64) of the canted data sets are processed (68) to generate a second derivative data set which is backprojected (70) in accordance with the Radon transform into a three-dimensional image representation.