Abstract: Apparatus and methods for fabricating scintillators for use in a CT systems are described. Adjacent scintillator elements are separated by gaps filled with a composition of white diffuse reflective material, a light absorber, and a castable polymer. The composition increases the strength of the signal to the photodiode by minimizing the amount of light that is lost by the scintillator elements. Additionally, the light absorber minimizes the amount of light transferred between adjacent scintillator elements to limit cross-talk. In addition, the outer edges of the scintillator may have a lower amount of light absorber to compensate for the light lost from the periphery.

Abstract: Apparatus and methods for fabricating scintillators for use in a CT systems are described. Adjacent scintillator elements are separated by gaps filled with a composition of white diffuse reflective material, a light absorber, and a castable polymer. The composition increases the strength of the signal to the photodiode by minimizing the amount of light that is lost by the scintillator elements. Additionally, the light absorber minimizes the amount of light transferred between adjacent scintillator elements to limit cross-talk. In addition, the outer edges of the scintillator may have a lower amount of light absorber to compensate for the light lost from the periphery.

Abstract: A flexible cable connection for a detector module is described. The flexible cable allows photodiode output signals to be coupled to the CT system without the need of attaching a pin connector to the photodiode outputs. Wires from the flexible cable are wire bonded to the photodiode output signals eliminating possible damage to the photodiode when the pin connector is attached.

Abstract: An elastomeric connector apparatus for a computed tomography system is described. In one embodiment, the elastomeric connector apparatus electrically connects a detector module flexible cable to a data acquisition backplane. Flexible cable and backplane connector pads are electrically connected with an elastomeric connector. The elastomeric connector apparatus allows the low level analog outputs from the detector module photodiodes to be transmitted to the backplane without a large pin connector array.

Abstract: A multislice detector array producing an alterable quantity of slices and slice resolutions. In one embodiment, the detector array includes a detector housing, a plurality of detector modules, and a collimator. Each detector module includes a plurality of photodiodes arranged in an array of rows and columns, a switch apparatus electrically coupled to the photodiode output signals, and a decoder. The collimator is configured to separate X-ray beams so that only the focal X-ray beams are impinged upon the detector modules.

Abstract: The present invention, in one form, is a scatter collimator for a computed tomography system including an x-ray source. The scatter collimator is positioned between a detector array and an object to be imaged. The scatter collimator includes a housing, a plurality of attenuating blades and a plurality of attenuating wires. The blades and wires are mounted to the housing, and oriented substantially perpendicular to each other. Particularly, the blades and wires form a two-dimensional shielding grid. The blades also are oriented so that they are radially and focally aligned with the x-ray source. A detector element of the detector array is secured to the housing so that the blades and wires are between the detector element and the x-ray source. The detector element, in one form, includes a scintillation element which is coated with a light-retaining material.

Abstract: A detector for detecting z-axis position in the plane of the fan beam of a computed tomography machine with respect to the detector array employs a pair of slotted masks over independent detector cells, the slots creating exposed widths that decrease and increase along their length. The intensity signals from the two detector cells so masked are subtracted to produce a z-axis position signal eliminating the effect of dark currents. Multiple cells may be ganged to reduce the effects of sensitivity variations among pairs of detector cells. The z-axis position signal may be used to control the z-axis position of the fan beam with respect to the detector array and to reduce the effect of the detector cell's variations in sensitivity.

Abstract: A computed tomography system corrects image errors resulting from misalignment of the fan beam as a result of placement of the x-ray tube, thermal drift of the x-ray tube anode of mechanical stresses of the gantry or x-ray tube. Misalignment is determined alternately by means of a z-axis offset detector which detects movement of the exposure area of the CT fan beam or a predictive model that calculates thermal drift of mechanical deflection of the focal spot of the x-ray tube based on previous use. The system includes a collimator with a controllable z-axis position which may be controlled to reduce z-axis offset of the fan beam exposure area or to make the fan beam more parallel with the imaging plane of the CT system.

Abstract: A multilayer film for coating an exterior of a scintillation detector bar includes a pressure sensitive adherent layer containing a percentage of a light-diffusing material therein for affixing to an external surface of the bar. A clear plastic layer separates the adherent layer from a specularly reflecting layer. A protective layer is disposed atop the specularly reflecting layer. The light-diffusing material and the specularly reflecting layer cooperate to retain light within the bar, direct light in random directions within the bar and block optical crosstalk between adjacent bars. A preform consisting of a single piece of film may be used for covering five sides of the bar.