X-ray intensifier detector system for x-ray electronic radiography

An x-ray intensifier detector system for detecting an x-ray fan beam, the detector system comprising:

• an x-ray image intensifier tube having an input window and a display screen for producing a light strip image representative of the x-ray pattern striking the input screen, the produced image having a longitudinal axis of symmetry, and wherein the image intensifier tube is of the proximity type and includes an elongated input window strip, an elongated, planar scintillator strip, an elongated, planar photocathode strip located immediately adjacent to the scintillator strip and between the scintillator strip and the output display screen, an output window immediately adjacent to the display screen, the display screen also being a planar strip, means for providing an electrostatic potential between the phosphor display screen and the photocathode, an evacuated housing surrounding the scintillator, the photocathode and the display screen which is closed at one end by the input window and which is closed at the other end by the output window, a metallic covering for the vacuum side of the display screen, the metallic covering being thick enough to dissipate at least one third of the kinetic energy of photoelectrons passing through it to strike the display screen;
• a first, scannable, linear array of discrete light detectors for sequentially detecting light generated along the longitudinal axis of the display image;
• and
• a scanning display for displaying the outputs of the detectors of the first array.

An x-ray intensifier detector system for detecting an x-ray fan beam, the detector system comprising:

• an x-ray image intensifier tube having a continuous strip of x-ray input screen and a continuous strip of output phosphor display screen for producing a light strip image representative of the x-ray pattern striking the input screen, the produced image having a longitudinal axis of symmetry,
• a first, scannable, linear array of discrete light detectors in view of the output phosphor display screen for sequentially detecting light generated along the longitudinal axis of the display image on the output phosphor display screen.
• a second, scannable, linear array of discrete light detectors in view of the output phosphor display screen for sequentially detecting light generated on the output phosphor display screen along a hypothetical line which is parallel to the longitudinal axis of the display image and spaced from it by a predetermined distance, the individual detectors of the first and second arrays having a physical correspondence to each other which is determined in part by the sequence in which they are scanned, and wherein the detectors of the second array are larger and more light sensitive than the corresponding detectors of the first array, and
• a scanning display for displaying the individual differences between the outputs of corresponding detectors of the first and second arrays.

In combination, a plurality of x-ray intensifier detector systems for detecting an x-ray fan beam, each detector system comprising:

• an x-ray image intensifier tube having a continuous strip of x-ray input screen and a continuous strip of output phosphor display screen for producing a light strip image representative of the x-ray pattern striking the input screen, the produced image having a longitudinal axis of symmetry,
• a first, scannable, linear array of discrete light detectors arranged in view of the output phosphor display screen for sequentially detecting light generated along the longitudinal axis of the display image on the output phosphor display screen,
• a second, scannable, linear array of discrete light detectors in view of the output phosphor display screen for sequentially detecting light generated on the output phosphor display screen along a hypothetical line which is parallel to the longitudinal axis of the display image and spaced from it by a predetermined distance, the individual detectors of the first and second arrays having a physical correspondence to each other which is determined in part by the sequence in which they are scanned,
• a scanning display for displaying the individual differences between the outputs of corresponding detectors of the first and second arrays,
• x-ray fan beam generator means for x-raying a patient by generating a plurality of x-ray fan beams, each fan beam being directed to a separate one of the detector systems,
• scanning means for holding the detector systems and the x-ray generator means in a predetermined alignment with each other while effecting relative movement between the patient on the one hand and the x-ray generator means and the detector system on the other hand, whereby the patient's body is scanned.

An x-ray intensifier detector system for detecting an x-ray fan beam, the detector system comprising:

• an x-ray image intensifier tube having a continuous strip of x-ray input screen and a continuous strip of output phosphor display screen for producing a light strip image representative of the x-ray pattern striking the input screen, the produced image having a longitudinal axis of symmetry,
• a first, scannable, linear array of discrete light detectors for sequentially detecting light generated along the longitudinal axis of the display image,
• a second, scannable, linear array of discrete light detectors for sequentially detecting light generated on the display screen along a hypothetical line which is parallel to the longitudinal axis of the display image and spaced from it by a predetermined distance, the individual detectors of the first and second arrays having a physical correspondence to each other which is determined in part by the sequence in which they are scanned,
• a scanning display for displaying the individual differences between the outputs of corresponding detectors of the first and second arrays, and
• an asymmetric post-scatter collimator, having a slit therein, located in front of the intensifier tube relative to the incoming x-ray beam, the collimator slit having a width which is twice the width of the x-ray fan beam and being placed so that the beam passes asymmetrically through one longitudinal side of the slit.

An x-ray intensifier detector system for detecting an x-ray fan beam, the detector system comprising:

• an x-ray image intensifier tube having an input window and a display screen for producing a light strip image representative of the x-ray pattern striking the input screen, the produced image having a longitudinal axis of symmetry, and wherein the image intensifier tube is of the proximity type and includes an elongated input window strip, an elongated, planar scintillator strip, an elongated, planar photocathode strip located immediately adjacent to the scintillator strip and between the scintillator strip and the output display screen, an output window immediately adjacent to the display screen, the display screen also being a planar strip, means for providing an electrostatic potential between the phosphor display screen and the photocathode, an evacuated housing surrounding the scintillator, the photocathode and the display screen which is closed at one end by the input window and which is closed at the other end by the output window, a metallic covering consisting substantially of aluminum, for the vacuum side of the display screen, wherein the thickness of the metallic covering is defined by:
• t=(k.sub.1 /.rho.)(E/3)k.sub.2
• where
• t=covering thickness in centimeters (cm)
• .rho.=density of covering in grams per cubic centimeter (gm/cm.sup.3)
• E=energy of the electron in electron volts (ev)
• k.sub.1 =5.times.10.sup.-3 milligrams/cm.sup.2 /Kev
• k.sub.2 =1.67
• a first, scannable, linear array of discrete light detectors for sequentially detecting light generated along the longitudinal axis of the display image;
• and
• a scanning display for displaying the outputs of the detectors of the first array.

An x-ray intensifier detector system for an x-ray fan beam, the detector system comprising:

• an x-ray image intensifier tube having a continuous strip of x-ray input screen and a continuous strip of output phosphor display screen for producing a light strip image representative of the x-ray pattern striking the input screen, the produced image having a longitudinal axis of symmetry.
• a post-scatter collimator, having a slit therein, located in front of the intensifier tube relative to the incoming x-ray beam,
• a first, scannable, linear array of discrete light detectors arranged in view of the output phosphor display screen for sequentially detecting light generated along the longitudinal axis of the display image on the output phosphor display screen,
• a second, scannable, linear array of discrete light detectors in view of the output phosphor display screen for sequentially detecting light generated on the output phosphor display screen along with a hypothetical line which is parallel to the longitudinal axis of the display image and spaced from it by a predetermined distance, the individual detectors of the first and second arrays having a physical correspondence to each other which is determined in part by the sequence in which they are scanned, and
• a scanning display for displaying the individual differences between the outputs of corresponding detectors of the first and second arrays.

In combination, x-ray fan beam generator means for x-raying a patient,

• an x-ray image intensifier tube having a continuous strip of x-ray input screen and a continuous strip of output phosphor display screen for producing a light strip image representative of the x-ray pattern striking the input screen, the produced image having a longitudinal axis of symmetry,
• a first, scannable, linear array of discrete light detectors arranged in view of the output phosphor display screen for sequentially detecting light generated along the longitudinal axis of the display image on the output phosphor display screen,
• a second, scannable, linear array of discrete light detectors in view of the output phosphor display screen for sequentially detecting light generated on the output phosphor display screen along a hypothetical line which is parallel to the longitudinal axis of the display image and spaced from it by a predetermined distance, the individual detectors of the first and second arrays having a physical correspondence to each other which is determined in part by the sequence in which they are scanned,
• a plurality of primary arrays of discrete light detectors, including the first array, which are scannable in a direction parallel to the plane of the fan beam for detecting the display image, means for effecting movement of the patient relative to the fan beam whereby each one of a predetermined number of hypothetical lines running through the patient and transverse to the direction of movement is sequentially aligned over each one of the primary arrays of light detectors, multiplexing means for combining the outputs for each primary array for each hypothetical line to produce line by line sum signals, and
• a scanning display for displaying the individual differences between the outputs of corresponding detectors of the first and second arrays, and wherein the scanning display displays the sum signals line by line to form an image.