Three-dimensional rectilinear scanner

• US 3,988,585 A
• Filed: 06/05/1975
• Issued: 10/26/1976
• Est. Priority Date: 06/11/1974
• Status: Expired due to Term

• Current Assignee: Optical Data Systems Incorporated
• Original Assignee: Optical Data Systems Incorporated
• Inventors: O'Neill, William J., Strange, Donald R., Miller, Philip A.
• Primary Examiner(s): Dixon, Harold A.
• Application Number:
  US05/583,917
• Time in Patent Office: 509 Days
• Field of Search: 250/367, 250/505, 250/363 S
• US Class Current: 250/363.02
• CPC Class Codes: A61B 6/4258 for detecting non x-ray radiation, e.g. gamma radiation A61B6/037 takes precedence
• CPC Class Codes: G01T 1/166 involving relative movement between detector and subject scanners in general without using scintigraphy G01T1/2964
• CPC Class Codes: G01T 1/2985 In depth localisation, e.g. using positron emitters; Tomographic imaging (longitudinal and transverse section imaging; apparatus for radiation diagnosis sequentially in different planes, steroscopic radiation diagnosis); using external radiation sources A61B6/02

Abstract

A rectilinear scanner for detecting radiation in a plurality of channels utilizing a collimator. Each of the channels receives information from a different portion of the collimator. Information separately received is separately massaged and later collated to present a common image. The information is processed by apparatus in a data processing system. This system has means for massaging analog signals corresponding to gamma radiation counts. This system has means for converting such analog signals to digital signals. This system has means interfacing the digital signals into an address register that communicates directly via data busses to core memory of a central processing unit by cycle stealing. This system has means deriving clinically significant information by computation on the resultant digital data. This system has means storing, retrieving, and displaying the resultant digital data and the resultant derivations therefrom collectively. This is done in such a manner as to allow time sequencing of the aforementioned operations such that the aforementioned operations can be interleaved on a real time basis.

Claims

1. In a tomographic gamma ray imaging device for detecting radiation dispersed within or transmitted through a patient and displaying an illustration of such distribution, the improvements comprising:

a head traversing the patient;

said head having a collimator;

a plurality of crystal members mounted on top of said collimator within said head;

said collimator comprising a lead shield relatively impervious to the passage of gamma radiation;

arrays of apertures within said collimator allowing the conduction of gamma radiation through said apertures;

each of said apertures having a focal axis directed towards a point below said collimator;

said point lying on the focal axes of all of said apertures;

said point lying within a focal plane from which radiation is detected by said head through said apertures in said collimator;

each of said crystal members responding electromagnetically to radiation from a different one of the arrays of apertures in said collimator;

each of said crystal members responding to radiation simultaneously to each of the other crystal members responding to radiation;

each of said focal axes of said apertures intercepting with one another and being at acute angles with respect to each other;

said head passing over a source of radiation in such a manner that electromagnetic response from one of said crystal members is discrete from and chronologically displaced from an electromagnetic response of another one of said crystal members.

2. In the apparatus of claim 1, photomultiplier tube members each responding to electromagnetic signals generated by one of said crystal members;

means communicating the response of said photomultiplier tube members to an oscillograhic display member;

said oscillographic display member operable to receive response from said photomultiplier tube members in separate and distinct channels which, in turn, each separately and distinctly respond to electromagnetic signals from one of said crystal members;

4. In the apparatus of claim 2, an optical viewer having two lenses with parallel optical axes focused on parallel but separate and distinct images displayed on said oscillographic display member where each such image is responsive to a different one of said separate channels.

5. In the apparatus of claim 2, the further improvements comprising:

an array of photomultiplier tube members each responding to electromagnetic signals generated by one of said crystal members;

an array of linear preamplifiers each generating an electrical signal responsive to said response from different one of said photomultiplier tube members;

an array of linear amplifiers each generating a signal responsive to said electrical signal from a different one of said linear preamplifiers;

an array of energy discriminators each emitting signals within predetermined amplitude limits responsive to said signals being generated from a different one of said linear amplifiers;

a computer interface apparatus emitting signals within a form cognizable by a central processing unit of a digital computer, each such signal being responsive to said signals being emitted by a different one of said energy discriminators;

and means operable to calculate and display mathematical and graphical representations of said distribution responsive to said computer interface emitting signals.

6. In the apparatus of claim 1, the further improvements comprising:

a plurality of photomultiplier tube members;

each of said photomultiplier tube members being responsive to electromagnetic radiation from one of said crystal members;

each of said photomultiplier tube members being unresponsive to another one of said crystal members;

each one of said photomultiplier tube members responsive to electromagnetic signals from a different one of said crystal members simultaneously to another one of said photomultiplier tube members being responsive to another one of said crystal members;

an analog to digital converter having a plurality of channels;

each of said channels being responsive to one of said photomultiplier tube members but being unresponsive to any of the other of said photomultiplier tube members;

a general purpose computer apparatus having a plurality of arrays of data channels;

one array of said data channels being responsive to one of said channels in said analog to digital converter;

said one array of data channels being unresponsive to other channels in said analog to digital converter;

data manipulation means in said computer being operable to massage data entered into the general computer apparatus through said data channels;

means for separately and discretely storing information after said data massage from a different one of each of said arrays of data channels;

and means for displaying the results of said data massage.

7. In the apparatus of claim 5, the improvements comprising:

said display means comprising oscillographic means for simultaneous two-dimensional representation of data massage results eminating from a different one of said arrays of data channels;

said oscillographic means also having electrical means for displaying mathematical, graphical representations of massaging data from a different one of each of said arrays of data channels;

and means for collating responses from different arrays of data channels into a single representation illustrative of depth calculations.

8. In the apparatus of claim 1, the further improvments comprising:

an array of photomultiplier tube members each responding to electromagnetic signals generated by one of said crystal members;

an array of linear preamplifiers each generating an electrical signal responsive to said response from different one of said photomultiplier tube members;

an array of linear amplifiers each generating a signal responsive to said electrical signal from a different one of said linear preamplifiers;

an array of energy discriminators each emitting signals within predetermined amplitude limits responsive to said signals being generated from a different one of said linear amplifiers;

a computer interface apparatus emitting signals within a form cognizable by a central processing unit of a digital computer each such signal being responsive to said signals being emitted by a different one of said energy discriminators.

9. In the apparatus of claim 7, the further improvements comprising:

said computer interface apparatus comprising an interface leveling buffer, a buffer output, an address selector, an interrupt function apparatus, a counter and a byte mode circuit;

said central processing computer comprising a data bus member, an accumulator and a memory storing device;

said interface leveling buffer operable to send a request signal to said data bus member responsive to said signals and emitting from said energy discriminator;

said data bus member operable to transmit an execute signal to said buffer output responsive to said request signal received from said address selector;

said interrupt function apparatus operable to enable said address selector for operation responsive to a signal received from said counter;

said central processing unit data bus member operable to transmit data to a data field within said memory device without passing such data through said accumulator;

said accumulator operable to derive information from said data field responsive to instructions from a stored program within said memory device;

whereby data reflective of radiation passing through said collimator can be stored in the data field of said memory device while being interleaved with other simultaneous operations of said central processing unit being processed through the accumulator of said central processing unit.

10. In the apparatus of claim 8, the further improvements comprising:

a derived calculation field within said memory storage device;

said central processing unit deriving calculations from data stored in said data field responsive to a stored program stored within said memory device;

said other simultaneous operations comprising the derivation of calculations by said central processing unit and storage of the results in said derived calculation field.

11. In the apparatus of claim 8, the further improvements comprising:

a display field within said memory storage device;

said central processing unit operable to calculate display information from data stored in said data field and store the resultant display information in said display field responsive to a stored program within said memory device;

an oscillographic display member operatively connected to said central processing unit and operable to display said display information from said display field responsive to a stored program within said memory storage device;

said other simultaneous operations comprising the calculation and storage of said display information by said central processing unit and display of said display information by said display member.

12. In the apparatus of claim 10, the further improvements comprising:

said display field being subdivided into sub-fields where each said sub-field corresponds to display information for one corresponding sub-field of said data field where the data in that sub-field is derived from the signals of one of said energy discriminators;

said oscillographic display member being operable to separately, distinctyl, and simultaneously display the display information from each of said sub-fields in said display field;

a derived calculation field within said memory storage device;

said central processing unit deriving calculations from data stored in said data field responsive to a stored program stored within said memory device;

said derived calculation field being subdivided into sub-fields where each said sub-field corresponds to derived calculations for one corresponding sub-field of said data field where the data in that sub-field is derived from the signals of one of said energy discriminators;

said other simultaneous operations further comprising the derivation of calculations by said central processing unit and storage of the results in said derived calculation field.

3. said oscillographic display member operable to simultaneously separately and distinctly display the responses received along said separate channels.

13. In a method of tomographic gamma ray imaging, the improvements comprising:

scanning gamma radiation along a predetermined planar path;

shielding a preselected portion of radiation from detection;

shielding another portion of radiation from detection simultaneously;

simultaneously funneling radiation through a preselected portion of said shielding;

simultaneously funneling another portion of radiation through another portion of shielding;

said funneling having a common point of intersection on a central focal plane;

discretely, separately, and simultaneously obtaining crystalographic electromagnetic response from said separate preselected funneling of radiation;

counting by photomultiplication in separate channels in a discrete and simultaneous manner the separately detected electromagnetic radiation;

converting resultant electromagnetic signals in continuous form to discrete pulsating digital signals in separate channels simultaneously from said counting by photomultiplication;

channeling the digitized data into computer data banks and maintaining the separate and distinct separation thereof provided by previous steps;

massaging the data by data processing in said computer;

and simultaneously illustrating resultant tomographic radioactive counts on a predetermined matrix separately and distinctly for the previously channeled and separated flow of signals.

14. In a tomographic gamma ray imaging device for detecting radiation dispersed within a patient and displaying an illustration of such distribution in a mathematical and graphical representation of such distribution, the improvements comprising:

a head;

said head having a colllimator;

a crystal member mounted on top of said collimator within said head;

said collimator comprising a lead shield relatively impervious to the passage of gamma ray radiation;

an array of apertures in said collimator allowing the conduction of gamma ray radiation through said apertures;

each of said apertures having a focal axis directed towards a point below said collimator;

said point lying on the focal axis of each of said apertures;

said point lying within focal plane from which radiation is detected by said head through said apertures in said collimator;

each said focal axis of said apertures intercepting with one another and being at an acute angle with respect to each other;

said crystal emitting a light signal responsive to nuclear radiation passing through said array of apertures;

a photomultiplier tube emitting a signal responsive to light emitted from said crystal;

a linear preamplifier generating an electrical signal responsive to said signal from said photomultiplier tube;

a linear amplifier generating a signal responsive to said signal being generated from said linear preamplifier;

an energy discriminator emitting signals within predetermined amplitude limits responsive to said signal being generated from said linear amplifier;

a machine wired computer interface apparatus emitting a signal within a form cognizable by a central processing unit of a digital computer responsive to said signals being emitted by said energy discriminator;

said computer interface apparatus comprising an interface leveling buffer, a buffer output, an address selector, an interrupt function apparatus, a counter, and a byte mode circuit;

said central processing computer comprising a data bus, an accumulator and a memory storing device;

said interface leveling buffer operable to send a request signal to said data bus responsive to said signals emitting from said energy discriminator;

said data bus operable to transmit an execute signal to said buffer output responsive to said request signal received from said address selector;

said interrupt function apparatus operable to enable said address selector for operation responsive to a signal received from said counter;

said central processing unit data bus operable to transmit data to a data field within said memory device without passing such data through said accumulator;

said accumulator operable to derive information from said data field responsive to instructions from a stored program within said memory device;

whereby data reflective of radiation passing through said collimator can be stored in the data field of said memory device while being interleaved with other simultaneous operations of said central processing unit being processed through the accumulator of said central processing unit.