Abstract: Storage capacitor array for a solid state radiation imager. The imager includes several pixels disposed on a substrate in an imaging array pattern. Each pixel includes a photosensor coupled to a thin film switching transistor. Several scan lines are disposed at a first level with respect to the substrate along a first axis and several data lines are disposed at a second level along a second axis of the imaging array. Capacitors are disposed on the substrate, wherein each capacitor has a first electrode coupled to a corresponding photosensor and a corresponding thin film transistor and a second electrode coupled to a capacitor linear electrode.

Abstract: A method for fabricating a radiation detector including at least one Thin Film Transistor (TFT) includes forming a low resistance data line strap unitary with a light block element on the TFT.

Abstract: A technique is provided for reducing or eliminating spectrally-sensitive artifacts in an X-ray image. In particular, a technique is provided in which a gain correction map derived for a detector at one X-ray spectrum may be adapted to accommodate images acquired by the detector at a different X-ray spectrum. The technique accounts for the physical variations in the detector which may produce spectrally-sensitive artifacts as well as for the particular image acquisition conditions. A technique is also provided for correcting edge artifacts in an acquired image by measuring median signal intensity within columns or rows of the image and deriving correction factors for the respective edge columns or rows based upon the trends of the median signal intensities. A technique is also provided for storing detector attributes during a manufacturing calibration process and accessing them during system operation such that a suitable gain correction factor is employed based upon the spectrum and operating conditions.

Abstract: A method for fabricating an imaging array includes forming a first dielectric barrier, forming a light block element on the first dielectric barrier, wherein the light block element is at least coextensive with a gate, and forming a second dielectric barrier on the first dielectric barrier and the light block element such that the light block element is encapsulated between the first dielectric barrier and the second dielectric barrier.

Abstract: A radiation detector includes a top gate thin film transistor (TFT) including a source electrode, a drain electrode, a gate electrode, a first dielectric layer, and a second dielectric layer, wherein the second dielectric layer is extending over a surface of the first dielectric layer. The radiation detector also includes a capacitor that includes at least two electrodes and a dielectric layer. The capacitor dielectric layer is formed unitarily with the TFT second dielectric layer.

Abstract: A technique for compensating for a retained image includes employing bimodal readout of alternating light and dark images. The bimodal readout technique results from reading either light or dark frames more rapidly, allowing additional time to be allocated to the X-ray exposures occurring prior to the light frames or to the other reading operation. The bimodal readout may be accomplished by a binning procedure by which scan lines are binned and read, typically during dark frame readout. The images acquired from reading the dark frames may then be used to compensate for a retained image artifacts present in the image derived from light frames.

Abstract: A method for fabricating a radiation detector including at least one Thin Film Transistor (TFT) includes forming a low resistance data line strap unitary with a light block element on the TFT.

Abstract: A radiation detector includes a top gate thin film transistor (TFT) including a source electrode, a drain electrode, a gate electrode, a first dielectric layer, and a second dielectric layer, wherein the second dielectric layer is extending over a surface of the first dielectric layer. The radiation detector also includes a capacitor that includes at least two electrodes and a dielectric layer. The capacitor dielectric layer is formed unitarily with the TFT second dielectric layer.

Abstract: A method is provided for identifying detector elements in a solid state X-ray detector susceptible to causing line artifacts due to faulty detector elements that leak charge. A portion of the X-ray detector is covered by a radiation occluding material and the detector is exposed to a level of radiation sufficient to reach a predetermined threshold in the exposed portion of the detector. An image representative of the radiation is acquired and further analyzed to determine whether line artifacts exist. Data lines found to exhibit line artifacts are stored in the image processor.

Abstract: In one aspect of the invention a method for processing a fluoroscopic image is provided. The method includes scanning an object with an imaging system including at least one radiation source and at least one detector array, acquiring a plurality of dark images to generate a baseline image, acquiring a plurality of lag images subsequent to the baseline image, determining a plurality of parameters of a power law using at least one lag image and at least one baseline image, and performing a log—log extrapolation of the power law including the determined parameters.

Abstract: In one aspect of the invention a method for processing a fluoroscopic image is provided. The method includes scanning an object with an imaging system including at least one radiation source and at least one detector array, acquiring a plurality of dark images to generate a baseline image, acquiring a plurality of lag images subsequent to the baseline image, determining a plurality of parameters of a power law using at least one lag image and at least one baseline image, and performing a log-log extrapolation of the power law including the determined parameters.

Abstract: A method is provided for identifying detector elements in a solid state X-ray detector susceptible to causing line artifacts due to faulty detector elements that leak charge. A portion of the X-ray detector is covered by a radiation occluding material and the detector is exposed to a level of radiation sufficient to reach a predetermined threshold in the exposed portion of the detector. An image representative of the radiation is acquired and further analyzed to determine whether line artifacts exist. Data lines found to exhibit line artifacts are stored in the image processor.

Abstract: An imaging system including a radiation spectral filter is provided for improving the quality of images obtained without increasing the dosage of radiation to the patient, and a method for improving image quality using such filtering are provided. The radiation filter is made of a material of a high atomic number, in order to filter out low energy and high energy x-rays from the beam of radiation prior to the beam being passed through the object to be imaged.

Abstract: A light block material disposed over the photosensitive region of a switching device (e.g., TFT) of a radiation imager is disclosed. The light block material prevents optical photons emitted from a scintillator from passing into the switching device and being absorbed. Cross-talk and noise in the imager are thereby reduced. Also, non-linear pixel response and spurious signals passing to readout electronics are avoided. Optionally, opaque caps comprising the same light block material may be included in the imager structure. The caps cover contact vias filled with a common electrode and located in the contact finger region of the imager. The integrity of the filled vias is thereby maintained during subsequent processing. Also disclosed is a radiation imager containing these structures.

Abstract: A system for correcting exposure signals generated by a matrix-addressed x-ray imaging panel by compensating for amplifier offset and gain artifacts in integrating read-out amplifiers connected to a matrix-addressed array of photosensors in an imaging panel. An average amplifier offset is calculated in a sequence of operations tinder control of a scan line controller and is applied to the exposure signals during normal operation of the imaging panel. A base gain calibration image is obtained periodically and is updated on a real-time basis by a real-time gain determined optionally whenever exposure signals are generated during normal operation of the imaging panel. The resulting real-time adjusted gain calibration image is divided into the amplifier offset adjusted exposure signals on a pixel-by-pixel basis to yield an exposure signal compensated for offset and gain on a real-time basis.

Abstract: A fiber optic scintillator includes, for example, a first plurality of radiation absorbing elements comprising a scintillating material for converting radiation into light and a second plurality of radiation absorbing elements interspersed among the first plurality of radiation absorbing elements. The first plurality of radiation absorbing elements has a first radiation absorption efficiency. The second plurality of radiation absorbing elements has a second radiation absorption efficiency and an effective atomic number greater than about 50. The second radiation absorption efficiency is greater than said first radiation absorption efficiency. A scintillator forming method provides a bundle of the second plurality of radiation absorbing elements interspersed among the first plurality of radiation absorbing elements by drawing the bundle, The drawn bundle is cut into a plurality of sections.

Abstract: A system for compensating for capacitively coupled artifacts in signals generated by a matrix-addressed x-ray imaging panel including a matrix-addressed array of sensing cells connected to respective integrating read-out amplifiers. While all scan lines are de-energized, a plurality of induced signals output by each amplifier are read, accumulated and averaged by a processor to form respective average values. During normal image panel operation, while scan lines are energized, processor subtracts respective average values from image signals output by respective amplifiers. The result is rounded to obtain an integer value for an image signal corresponding to each amplifier that is compensated for capacitively coupled artifacts.

Abstract: A detector (20) for high voltage x-rays includes a plurality of sensor elements (22) with each sensor element being aligned along a respective focal axis (25) with respect to a high voltage x-ray source (24). A fiber optic scintillator (34) is optically coupled to each of said sensor elements and is disposed to receive incident x-ray radiation passing from the object to be imaged. Optical fibers of the scintillator are positioned such that their optical axes are perpendicular to incident x-rays. Each sensor element has a length along the focal axis sufficiently long for the fibers to absorb substantially all incident x-rays. Each sensor element comprises an array of amorphous silicon photosensors disposed to detect light generated by the scintillator.

Abstract: A radiation imager includes a photosensor array that is coupled to a scintillator so as to detect optical photons generated when incident radiation is absorbed in the scintillator. The imager includes an optical crosstalk attenuator that is optically coupled to a first surface of the scintillator (that is, the surface opposite the photosensor). The optical crosstalk attenuator includes an optical absorption material that is disposed so as to inhibit reflection of optical photons incident on the scintillator first surface back into the scintillator along selected crosstalk reflection paths. The crosstalk reflection paths are those paths oriented such that optical photons passing along such paths would be incident upon photosensor array pixels that are outside of a selected focal area corresponding to the absorption point in the scintillator.

Abstract: An imager array includes a substrate with a plurality of superimposed layers of electrically conductive and active components. Sets of scan and data lines are electrically insulated from one another and also from a common electrode and active array components by dielectric material. Protection of the active components against static charge potential includes resistive means between the common electrode and a ground ring conductor around the array elements and in particular a thin film transistor circuit with a parallel pair of opposite polarity diode connected field effect transistors to safely drain the static charge during subsequent fabrication, test and standby period of the imager, while remaining in circuit during imager operation.