Tomographic imaging device using a rotating slanted multichannel collimator

Claim 2

In a device for imaging the volume distribution of radionuclides throughout an object under investigation, in combination: a radiation detector, including a substantially planar radiation sensitive transducer, of the type producing an output representing plane position coordinates of each quantum of radiation interacting with said transducer, said detector adapted to be held stationary; support means for supporting said object in view of said detector; radiation shielding means interposed between said transducer and said object defining a substantially uniform radiation acceptance direction from said object to said transducer; and driving means operatively associated with said support means and said radiation shielding means for changing the position of said object with respect to said radiation detector and simultaneously changing said radiation acceptance direction defined by said radiation shielding means in a synchronous manner to produce predetermined patterned movement of images generated on said transducer by quanta of radiation emanating from radionuclides in elemental volumes of said object, said predetermined patterned movement differing in accordance with the volume position coordinates of each said elemental volume such that the output from said detector may be translated into useful information concerning the distribution of radionuclides across a plane through said object at any selected distance from said transducer.

Claim 3

The combination as claimed in claim 1, further comprising means receiving said output from said radiation detector operative to translate said output in accordance with said predetermined patterned movement into a useful image presentation of the distribution of radionuclides across a plane through said object at a preselected distance from said transducer.

Claim 4

In a device for imaging the volume distribution of radionuclides throughout an object under investigation, in combination: a radiation detector, including a substantially planar radiation sensitive transducer, of the type producing an output representing plane position coordinates of each quantum of radiation interacting with said transducer, said detector adapted to be held stationary; support means for supporting said object in view of said detector; a collimator of substantially radiation opaque material rotatably mounted on said detector between said transducer and said object, said material defining an array of mutually spaced apertures each having a common non-normal axial orientation with respect to said transducer; and driving means for simultaneously rotating said collimator and precessing said support means in a circle of selected radius in a synchronous manner such that elemental volumes of radionuclides on a reference plane through said object parallel to said transducer generate stationary images on said transducer and elemental volumes of radionuclides on other parallel planes generate images which are circular with a radius dependent upon the distance of each from said reference plane, the distance between said transducer and said reference plane being a predetermined function of said radius of circular precession and the degree of said non-normal axial orientation.

Claim 5

In a device for imaging the volume distribution of radionuclides throughout an object under investigation, in combination: a radiation detector, including a substantially planar radiation sensitive transducer, of the type producing an output representing plane position coordinates of each quantum of radiation interacting with said transducer, said detector adapted to be held stationary; support means for supporting said object in view of said detector; a collimator of substantially radiation opaque material rotatably mounted on said detector between said transducer and said object, said material defining an array of mutually spaced apertures each having a common non-normal axial orientation with respect to said transducer; and driving means for simultaneously rotating said collimator and precessing said support means in a circle of selected radius in a synchronous manner such that elemental volumes of radionuclides on a reference plane through said object parallel to said transducer generate stationary images on said transducer and elemental volumes of radionuclides on other parallel planes generate images which are circular with a radius dependent upon the distance of each from said reference plane, the distance between said transducer and said reference plane being a predetermined function of said radius of circular precession and the degree of said non-normal axial orientation.

Claim 6

The combination as claimed in claim 3, wherein said output of said detector comprises a first pair of signals representing said plane position coordinates; and further comprising: sensing means for producing a second pair of signals representing plane position coordinates of said precessing support means; and translating means receiving said first and second pairs of signals operative to produce a third pair of signals representing corrected position coordinates of each quantum of radiation iNteracting with said transducer, said corrected position coordinates being associated with an in-focus image of the distribution of radionuclides across a preselected plane through said object.

Claim 7

Apparatus for imaging the volume distribution of radionuclides throughout an object under investigation comprising, in combination: a radiation detector, including a substantially planar radiation sensitive transducer, of the type producing a first pair of output signals, x and y, representing plane position coordinates of each quantum of radiation interacting with said transducer, said detector adapted to be held stationary; support means for supporting said object in view of said detector; a multichannel radiation collimator rotatably mounted on said detector between said transducer and said object, the axis of each of the channels of said collimator making an angle theta with respect to a line normal to said transducer; driving means for simultaneously rotating said collimator and precessing said support means in a circle of selected radius R in a synchronous manner; sensing means for producing a second pair of signals, x'' and y'', representing plane position coordinates of said precessing support means as a function of time; translating means receiving said first and second pairs of signals operative to produce a third pair of signals, X and Y, in accordance with the following equations X x + kx'', Y y + ky'' where k is a predetermined proportion of the distance d of a plane through said object from a reference plane at a distance D from said transducer defined by the equation D R ctn theta , and k has a negative value for planes between said reference plane and said transducer and a positive value for planes on the other side of said reference plane; and image display means operative to produce an elemental indicia located in accordance with said third pair of signals.

Claim 8

Apparatus for imaging the volume distribution of radionuclides throughout an object under investigation comprising, in combination: a radiation detector, including a substantially planar radiation sensitive transducer, of the type producing a first pair of output signals, x and y, representing plane position coordinates of each quantum of radiation interacting with said transducer, said detector adapted to be held stationary; support means for supporting said object in view of said detector; a multichannel radiation collimator rotatably mounted on said detector between said transducer and said object, the axis of each of the channels of said collimator making an angle theta with respect to a line normal to said transducer; driving means for simultaneously rotating said collimator and precessing said support means in a circle of selected radius R in a synchronous manner; sensing means for producing a second pair of signals, x'' and y'', representing plane position coordinates of said precessing support means as a function of time; translating means receiving said first and second pairs of signals operative to produce a third pair of signals, X and Y, in accordance with the following equations X x + kx'', Y y + ky'' where k is a predetermined proportion of the distance d of a plane through said object from a reference plane at a distance D from said transducer defined by the equation D R ctn theta , and k has a negative value for planes between said reference plane and said transducer and a positive value for planes on the other side of said reference plane; and image display means operative to produce an elemental indicia located in accordance with said third pair of signals.

Claim 9

Apparatus for imaging an object having a three dimensional distribution of radioactivity therethroughout, comprising: a radiation detector including a radiation sensitive transducer having a two dimensional radiation detecting capability and output means associated with said transducer operative to produce visible elemental output signals corresponding in time and relative spatial displacement to the position of interaction of a quantum of radiation with said transducer, said detector adapted to be held stationary; a multichannel radiation collimator rotatably mounted on said detector in a position adjacent said transducer, the axis of each channel of said collimator having substantially the same non-normal angular orientation with respect to said transducer; support means for supporting said object in view of said detector through said collimator; and driving means for simultaneously rotating said collimator and precessing said support means in a circle of selected radius in a synchronous manner such that said object remains in view of said detector, whereby said output signals from said detector provide an in-focus image of the distribution of radionuclides across a particular plane through said object at a depth depending upon said angular orientation and said selected radius.

Claim 10

Apparatus for imaging an object having a three dimensional distribution of radioactivity therethroughout, comprising: a radiation detector including a radiation sensitive transducer having a two dimensional radiation detecting capability and output means associated with said transducer operative to produce visible elemental output signals corresponding in time and relative spatial displacement to the position of interaction of a quantum of radiation with said transducer, said detector adapted to be held stationary; a multichannel radiation collimator rotatably mounted on said detector in a position adjacent said transducer, the axis of each channel of said collimator having substantially the same non-normal angular orientation with respect to said transducer; support means for supporting said object in view of said detector through said collimator; and driving means for simultaneously rotating said collimator and precessing said support means in a circle of selected radius in a synchronous manner such that said object remains in view of said detector, whereby said output signals from said detector provide an in-focus image of the distribution of radionuclides across a particular plane through said object at a depth depending upon said angular orientation and said selected radius.

Claim 11

Apparatus for producing a tomographic image of an object containing a three dimensional distribution of radionuclides comprising, in combination: an Anger-type radiation detector fixed in a stationary position; a multichannel radiation collimator rotatably mounted on said detector, the axis of each channel of said collimator having substantially the same non-normal angular orientation with respect to said detector; support means including a floatable table for supporting said object in a movable fashion adjacent said collimator; and driving means for simultaneously rotating said collimator and precessing said table in a cIrcle of preselected radius in a synchronous manner to produce automatically a displayed in-focus image of the distribution of radionuclides across a plane through said object at a depth determined by said selected radius and the angle of said collimator channels.

Claim 12

Apparatus for producing a tomographic image of an object containing a three dimensional distribution of radionuclides comprising, in combination: an Anger-type radiation detector fixed in a stationary position; a multichannel radiation collimator rotatably mounted on said detector, the axis of each channel of said collimator having substantially the same non-normal angular orientation with respect to said detector; support means including a floatable table for supporting said object in a movable fashion adjacent said collimator; and driving means for simultaneously rotating said collimator and precessing said table in a cIrcle of preselected radius in a synchronous manner to produce automatically a displayed in-focus image of the distribution of radionuclides across a plane through said object at a depth determined by said selected radius and the angle of said collimator channels.

Claim 13

Apparatus as claimed in claim 7, further comprising circuit means for transforming the position coordinate signals in said detector in accordance with said circular precession such that said detector selectively produces a displayed in-focus image of the distribution of radionuclides across other planes through said object.

Claim 14

Apparatus for producing a tomographic image of an object containing a three-dimensional distribution of radio-nuclides comprising, in combination: a radiation detector of the type producing relatively spaced light flashes corresponding to position coordinates of gamma rays interacting with said detector, said detector being fixed in a stationary position; a multichannel radiation collimator rotatably mounted on said detector, the axis of each channel of said collimator having substantially the same non-normal angular orientation with respect to said detector; support means including a floating table for supporting said object in a movable fashion adjacent said collimator; and driving means for simultaneously rotating said collimator and precessing said table in a circle of selected radius in a synchronous manner, whereby said detector automatically produces a displayed in-focus image of the distribution of radionuclides across a plane through said object at a depth determined by said selected radius and other planes may be imaged in-focus by altering said radius of precession or the distance between said object and said detector.

Claim 15

Apparatus for producing a tomographic image of an object containing a three-dimensional distribution of radio-nuclides comprising, in combination: a radiation detector of the type producing relatively spaced light flashes corresponding to position coordinates of gamma rays interacting with said detector, said detector being fixed in a stationary position; a multichannel radiation collimator rotatably mounted on said detector, the axis of each channel of said collimator having substantially the same non-normal angular orientation with respect to said detector; support means including a floating table for supporting said object in a movable fashion adjacent said collimator; and driving means for simultaneously rotating said collimator and precessing said table in a circle of selected radius in a synchronous manner, whereby said detector automatically produces a displayed in-focus image of the distribution of radionuclides across a plane through said object at a depth determined by said selected radius and other planes may be imaged in-focus by altering said radius of precession or the distance between said object and said detector.