Abstract: A multiple mode digital X-ray imaging system providing for preprocessing “binning” of analog pixel signals from a detector array by selectively summing, within the detector array, adjacent pixel charges on a row-by-row basis and selectively summing, within detector array readout circuits, the previously summed pixel charges (by rows) on a column-by-column basis. An array, or mapping, of “defective pixel” flags is used to identify defective pixels within the detector array, with such flags being added to, or inserted into, the incoming data stream for dynamic processing along with the incoming pixel data. A buffer and filter is used to perform still image capture during the radiographic mode of operation and to recursively filter incoming data frames during the fluoroscopic mode of operation by summing a scaled amount of pixel data from prior data frames with a scaled amount of incoming pixel data from the present data frame.

Abstract: A multiple mode digital X-ray imaging system providing for preprocessing “binning” of analog pixel signals from a detector array by selectively summing, within the detector array, adjacent pixel charges on a row-by-row basis and selectively summing, within detector array readout circuits, the previously summed pixel charges (by rows) on a column-by-column basis. An array, or mapping, of “defective pixel” flags is used to identify defective pixels within the detector array, with such flags being added to, or inserted into, the incoming data stream for dynamic processing along with the incoming pixel data. A buffer and filter is used to perform still image capture during the radiographic mode of operation and to recursively filter incoming data frames during the fluoroscopic mode of operation by summing a scaled amount of pixel data from prior data frames with a scaled amount of incoming pixel data from the present data frame.

Abstract: A multiple mode digital X-ray imaging system providing for preprocessing "binning" of analog pixel signals from a detector array by selectively summing, within the detector array, adjacent pixel charges on a row-by-row basis and selectively summing, within detector array readout circuits, the previously summed pixel charges (by rows) on a column-by-column basis. An array, or mapping, of "defective pixel" flags is used to identify defective pixels within the detector array, with such flags being added to, or inserted into, the incoming data stream for dynamic processing along with the incoming pixel data. A buffer and filter is used to perform still image capture during the radiographic mode of operation and to recursively filter incoming data frames during the fluoroscopic mode of operation by summing a scaled amount of pixel data from prior data frames with a scaled amount of incoming pixel data from the present data frame.

Abstract: Disclosed is a low cost computer tomographic (CT) scanner system specifically designed for radiation therapy treatment planning. A 512-channel photo-diode array with digitizing electronics converts image intensifier optical projection data directly into digital signals and has a dynamic range on the order of 100,000:1. The new simulator includes a rotating gantry, an X-ray generator with radiographic and fluoroscopic modes and a therapy style patient support assembly. Results on head and body size phantoms indicate that the simulator X-ray generator and image intensifier tube (IIT) with multi-channel photo-detector can produce photon statistic limited CT images. Software and hardware compensation methods are described which minimize geometrical distortions. Low noise, high input impedance electronics are employed which are phase-locked to the line frequency.

Abstract: A slow scanning CT Scanner providing slice data simultaneously for a plurality of slices so as to avoid blurring between adjacent slices due to patient movement.

Abstract: Disclosed is a method for improving the dynamic resolution of an imaging system. The method employs a dual sampling or exposure technique which samples light from an image intensifier over a long and a short sample interval. When the resulting measurement for the long sample interval exceeds a threshold level, the short sample interval measurement is used, multiplied by a scaling factor. Below the threshold the long sample interval is used.

Abstract: The detector of the present invention is suitable for use in a radiation therapy simulator machine. The detector comprises an X-ray image intensifier tube to convert X-rays into photons, a linear array of photodiodes to convert the photons to electrical signals, optical means for coupling the photons to the linear array of photodiodes, and electronic signal processing means for conditioning the signals from the photodiodes. The conditioning includes the use of low noise, phaselocked sampling electronics, implementation of a dual sampling technique for increasing dynamic range, implementation of a linearizing technique for increasing the accuracy of the measurements, and implementation of techniques for adjusting the measurements for point spread and background noise effects.

Abstract: Disclosed is a method for increasing the accuracy of images obtained in radiation therapy apparatus, such as a computed tomography simulator which employs an image intensifier and a photodiode detector for converting light from the image intensifier to electrical signals for further processing. The method recognizes that a significant amount of crosstalk can exist in the image intensifier and photodiode detector chain and provides a series of steps for adjusting the electrical signals obtained from the photodiode detector to compensate for the crosstalk.

Abstract: Scanning apparatus is disclosed for use in computerized axial tomography systems. The apparatus includes an assembly rotatable about an axis extending along a central opening defined therein, and means for positioning the body portion to be examined within the central opening so that the axis of assembly rotation is perpendicular to a plane passing through the bodily structures to be examined. A source of penetrating radiation is mounted on the assembly toward one side thereof and provides radiation in the form of a fan beam. Detector means for the radiation are positioned on the assembly opposite the source, enabling detection of radiation which traverses laterally and is not absorbed in the thin body section in which the aforementioned plane resides. Means are provided for rotating the assembly so that the fan beam impinges upon said body portion at a plurality of incident directions.

Abstract: A wide bandwidth compressional wave transducer array obtains information concerning tissue of a subject being treated and supplies hyperthermia compressional wave treating energy to a treated region of the subject. The array transducers are pulsed on and off with an on duty cycle portion of less than one. An array of compressional wave imaging transducers is in the center of the array of compressional wave hyperthermia focused far field transducers used to analyze and treat. The power and duty cycle of the compressional wave hyperthermia focused far field are varied to control the energy incident on certain regions in a treated subject. The ultrasonic frequencies of hyperthermia beams derived from individual transducers are randomly angle modulated so the energy of adjacent far field focused beams overlaps to a greater extent than focused coherent beams.

Abstract: Temperature inside a tissue volume is noninvasively determined on the basis of its known relationship with the velocity of ultrasound inside the volume. The velocity of ultrasound between two field points inside the volume of interest is calculated from measurements of differences in transit times of sound beams scattered in substantially opposite directions at these field points.

Abstract: Scanning apparatus is disclosed for use in computerized axial tomography systems. The apparatus includes an assembly rotatable about an axis extending along a central opening defined therein, and means for positioning the body portion to be examined within the central opening so that the axis of assembly rotation is perpendicular to a plane passing through the bodily structures to be examined. A source of penetrating radiation is mounted on the assembly toward one side thereof and provides radiation in the form of a fan beam. Detector means for the radiation are positioned on the assembly opposite the source, enabling detection of radiation which traverses laterally and is not absorbed in the thin body section in which the aforementioned plane resides. Means are provided for rotating the assembly so that the fan beam impinges upon said body portion at a plurality of incident directions.

Abstract: An axial tomography system is disclosed which includes an assembly rotatable about an axis extending along a central opening defined therein, and means for positioning the body portion to be examined within the central opening so that the axis of assembly rotation is perpendicular to a plane passing through the bodily structures to be examined. A source of penetrating radiation is mounted on the assembly toward one side thereof and provides radiation in the form of a fan beam. Means are provided for rotating the assembly so that the fan beam impinges upon said body portion at a plurality of incident directions. Detector means for the radiation are positioned on the assembly opposite the source, enabling detection of radiation which traverses laterally and is not absorbed in the thin body section in which the aforementioned plane resides.

Abstract: An axial tomography system is disclosed which includes an assembly rotatable about an axis extending along a central opening defined therein, and means for positioning the body portion to be examined within the central opening so that the axis of assembly rotation is perpendicular to a plane passing through the bodily structures to be examined. A source of penetrating radiation is mounted on the assembly toward one side thereof and provides radiation in the form of a fan beam. Means are provided for rotating the assembly so that the fan beam impinges upon said body portion at a plurality of incident directions. Detector means for the radiation are positioned on the assembly opposite the source, enabling detection of radiation which traverses laterally and is not absorbed in the thin body section in which the aforementioned plane resides.

Abstract: An axial tomography system is disclosed which includes an assembly rotatable about an axis extending along a central opening defined therein, and means for positioning the body portion to be examined within the central opening so that the axis of assembly rotation is perpendicular to a plane passing through the bodily structures to be examined. A source of penetrating radiation is mounted on the assembly toward one side thereof and provides radiation in the form of a fan beam. Means are provided for rotating the assembly so that the fan beam impinges upon said body portion at a plurality of incident directions. Detector means for the radiation are positioned on the assembly opposite the source, enabling detection of radiation which traverses laterally and is not absorbed in the thin body section in which the aforementioned plane resides.

Abstract: An axial tomography system is disclosed which includes an assembly rotatable about an axis extending along a central opening defined therein, and means for positioning the body portion to be examined within the central opening so that the axis of assembly rotation is perpendicular to a plane passing through the bodily structures to be examined. A source of penetrating radiation is mounted on the assembly toward one side thereof and provides radiation in the form of a fan beam. Means are provided for rotating the assembly so that the fan beam impinges upon said body portion at a plurality of incident directions. Detector means for the radiation are positioned on the assembly opposite the source, enabling detection of radiation which traverses laterally and is not absorbed in the thin body section in which the aforementioned plane resides.

Abstract: Scanning apparatus is disclosed for use in computerized axial tomography systems. The apparatus includes an assembly rotatable about an axis extending along a central opening defined therein, and means for positioning the body portion to be examined within the central opening. A source of penetrating radiation is mounted on the assembly toward one side thereof and provides radiation in the form of a fan beam. Signal processing and conditioning means mounted on the assembly and movable therewith, receive the output signals from the detector means and amplify and convert same to digital form. Slip ring interconnection means, rotatable with the assembly, receive the outputs from the signal processors and conditioners and interfeed these signals to a computerized image reconstruction station. Slip rings rotatable with the assembly also provide interconnection enabling power and control inputs to the radiation source and to other portions of the apparatus.

Abstract: Scanning apparatus is disclosed for use in computerized axial tomography systems. The apparatus includes an assembly rotatable about an axis extending along a central opening defined therein, and means for positioning the body portion to be examined within the central opening so that the axis of assembly rotation is perpendicular to a plane passing through the bodily structures to be examined. A source of penetrating radiation is mounted on the assembly toward one side thereof and provides radiation in the form of a fan beam. Detector means for the radiation are positioned on the assembly opposite the source, enabling detection of radiation which traverses laterally and is not absorbed in the thin body section in which the aforementioned plane resides. Means are provided for rotating the assembly so that the fan beam impinges upon said body portion at a plurality of incident directions.

Abstract: System and method are set forth enabling reconstruction of images of desired "frozen action" cross-sections of the heart or of other bodily organs or similar objects undergoing cyclic displacements. Utilizing a computed tomography scanning apparatus data is acquired during one or more full rotational cycles and suitably stored. The said data corresponding to various angular projections can then be correlated with the desired portion of the object's cyclical motion by means of a reference signal associated with the motion, such as that derived through an electrocardiogram--where a heart is the object of interest. Data taking can also be limited to only the times when the desired portion of the cyclical motion is occurring. A sequential presentation of a plurality of said frozen action cross-sections provides a motion picture of the moving object.

Abstract: In an instrument for reconstructing computerized tomograms utilizing penetrating radiation, typically X or gamma radiation, an apparatus and technique are disclosed for removing spectral artifacts and utilizing spectral effects to create output pictures which represent facsimilies of the distribution of molecules according to atomic number and electron density within the object being pictured. Combinations of these pictorial representations are also obtained. Reconstruction errors caused by panchromaticity in the radiation source are avoided. Attenuation within the object by means of photoelectric absorption, Compton scattering and Rayleigh scattering are isolated and analyzed separately. Techniques are disclosed for treating source beams which are arbitrarily thin or of a finite thickness.