Abstract: An imaging apparatus (400) includes a detector array (412) with at least one detector tile (418). The detector tile includes a photosensor array (422) with a two dimensional array of individual photosensitive detector pixels (424) located within a non-photosensitive area (426) and readout electronics (432) coupled to the photosensor array. The readout electronics includes individual analog readout channel wells (602, 604) corresponding to the individual detector pixels, wherein an analog readout channel well electrically isolates analog electrical components therein from analog electrical components in other analog readout channel wells. Decoupling circuitry optionally is located in at least one of metal layers of the individual analog readout channels or in the individual analog readout channel wells.

Abstract: An imaging apparatus (400) includes a detector array (412) with at least one detector tile (418). The detector tile includes a photosensor array (422) with a two dimensional array of individual photosensitive detector pixels (424) located within a non-photosensitive area (426) and readout electronics (432) coupled to the photosensor array. The readout electronics includes individual analog readout channel wells (602, 604) corresponding to the individual detector pixels, wherein an analog readout channel well electrically isolates analog electrical components therein from analog electrical components in other analog readout channel wells. Decoupling circuitry optionally is located in at least one of metal layers of the individual analog readout channels or in the individual analog readout channel wells.

Abstract: A radiation detector module (22) particularly well suited for use in computed tomography (CT) applications includes a scintillator (200), a photodetector array (202), and signal processing electronics (205). The photodetector array (202) includes a semiconductor substrate (208) having a plurality of photodetectors and metalization (210) fabricated on non-illuminated side of the substrate (208). The metalization routes electrical signals between the photodetectors and the signal processing electronics (205) and between the signal processing electronics (205) and an electrical connector (209).

Abstract: A radiographic imaging apparatus (10) comprises a primary radiation source (14) which projects a beam of radiation into an examination region (16). A detector (18) converts detected radiation passing through the examination region (16) into electrical detector signals representative of the detected radiation. The detector (18) has at least one temporally changing characteristic such as an offset B(t) or gain A(t). A grid pulse means (64) turns the primary radiation source (14) ON and OFF at a rate between 1000 and 5000 pulses per second, such that at least the offset B(t) is re-measured between 1000 and 5000 times per second and corrected a plurality of times during generation of the detector signals. The gain A(t) is measured by pulsing a second pulsed source (86, 100, 138) of a constant intensity (XRef) with a second pulse means (88). The gain A(t) is re-measured and corrected a plurality of times per second during generation of the detector signals.

Abstract: A radiographic imaging apparatus (10) comprises a primary radiation source (14) which projects a beam of radiation into an examination region (16). A detector (18) converts detected radiation passing through the examination region (16) into electrical detector signals representative of the detected radiation. The detector (18) has at least one temporally changing characteristic such as an offset B(t) or gain A(t). A grid pulse means (64) turns the primary radiation source (14) ON and OFF at a rate between 1000 and 5000 pulses per second, such that at least the offset B(t) is re-measured between 1000 and 5000 times per second and corrected a plurality of times during generation of the detector signals. The gain A(t) is measured by pulsing a second pulsed source (86, 100, 138) of a constant intensity (XRef) with a second pulse means (88). The gain A(t) is re-measured and corrected a plurality of times per second during generation of the detector signals.

Abstract: A computerized tomographic imaging system including a stationary gantry portion defining an examination region and a rotating gantry portion for rotation about the examination region. An x-ray source is disposed on the rotating gantry portion for projecting x-rays through the examination region. A plurality of modular radiation detector units are disposed across the examination region from the x-ray source. Each radiation detector unit includes an array of x-ray sensitive cells for receiving radiation from the x-ray source after it has passed through the examination region and for generating an analog signal indicative of the radiation received thereby. Each radiation detector unit also includes a plurality of integrated circuits connected to the x-ray sensitive cells with each integrated circuit including a plurality of channels. Each channel receives the analog signal from an x-ray sensitive cell and generates digital data indicative of the value of the analog signal.

Abstract: A computerized tomographic imaging system including a stationary gantry portion defining an examination region and a rotating gantry portion for rotation about the examination region. An x-ray source is disposed on the rotating gantry portion for projecting x-rays through the examination region. A plurality of modular radiation detector units are disposed across the examination region from the x-ray source. Each radiation detector unit includes an array of x-ray sensitive cells for receiving radiation from the x-ray source after it has passed through the examination region and for generating an analog signal indicative of the radiation received thereby. Each radiation detector unit also includes a plurality of integrated circuits connected to the x-ray sensitive cells with each integrated circuit including a plurality of channels. Each channel receives the analog signal from an x-ray sensitive cell and generates digital data indicative of the value of the analog signal.

Abstract: A CT scanner (10) includes a reconstruction processor (32) for reconstructing an image from digital signals from detector arrays (20). Each detector array includes scintillation crystals (22) arranged in an array for converting x-ray radiation into light. An array of back-illuminated photo diodes (24) is mounted beneath the scintillation crystal array for converting the light emitted from the scintillation crystals into electrical charge. The electrical charge from the back-illuminated photodiodes is transmitted via a path orthogonal to the detector array (20, 40) to signal processing circuitry (66). The back-illuminated photodiode has a backside (26) which is in optical communication with the crystal array (22) and which is optically transmissive to photons of light emanating from the crystal. The converted electrical charge leaves the photodiode via electrical connections (28) or bump bonds (62, 72) on the front side of the photodiode.

Abstract: A CT scanner (10) includes a radiation source (12) mounted for rotation about a scan circle (14). A ring of radiation detectors (30) includes narrow detectors (30.sub.n) and wide detectors (30.sub.w). The narrow and wide detectors are separately sampled (42.sub.n, 42.sub.w) and operated on with different digital filters (50.sub.n, 50.sub.w). The wider detectors have a more limited frequency response (32) which typically includes an out of phase response portion (36); whereas, the output signal from the narrow detetector has a higher frequency response (34), i.e. better resolution. The filters (50.sub.n, 50.sub.w) are selected to yield optimum signal to noise ratio. When the data is merged (60), the resultant data has a modulation transfer function with response (62) which has a higher frequency component or improved resolution relative to response (70) that would be obtained from detectors of uniform width of the average of the narrow and detector widths.

Abstract: An imaging system acquires imaged data from a non-invasive examination of the subject. The data is transferred among various image processing agents on a data bus. A data acquisition agent receives the image data from the non-invasive examination and generates subsequent agent locations and transmits the subsequent agent locations and the packets of image data along the data bus. Various image processing agents each receive packets of data transmitted with that agent's location and performs imaging and processing operations on the data packets generating another agent location and thereafter transmitting the other agent location and process data packets along the data bus. The display agent receives the processed image data packets from one of the image processing agents via the data bus, stores the processed image data packets and communicates the process image data to a man-readable image display.

Abstract: A customized random access memory circuit is provided to allow the processing of extremely high amounts of data in an area of very small physical size. The chip contains a group of interconnected registers with a set of input ports and a set of output ports. The input ports have individual write enable signals to allow them to write to selected address locations. A switching circuit is provided to ensure that the proper data from the proper input port goes to the chosen address location. A first and second set of latches are provided where the first set of latches are connected to a multiplexor first and the second set of latches are connected to a second multiplexor. The chip also contains a cycle skipping chip to allow the data to maintain its position and not be transferred through at least one clock cycle. Selected data sets which are going to be outputted have the data internally swapped to prepare it for use in floating point operations.

Abstract: An array processor has been designed in a highly paralleled fashion thereby allowing extremely fast movement of data. Two 32-bit words come out of an internal data memory device. This data is fed into a register file. On the same clock cycle, three 32-bit results are coming out of an arithmetic unit. Those results feed back into the register file. Therefore, on a single clock cycle, five separate pieces of data are going into the register file. In the same clock cycle, other data coming out of the outputs of the register file feed data into two separate floating arithmetic adders and one floating arithmetic multiplier. The design of the present embodiment allows a constant flow of data to be supplied to the arithmetic unit thereby using the arithmetic unit to its maximum functioning ability.