Scanning beam x-ray imaging system

• US 5,835,561 A
• Filed: 04/10/1995
• Issued: 11/10/1998
• Est. Priority Date: 01/25/1993
• Status: Expired due to Term

• Current Assignee: Airdrie Partners I LP
• Original Assignee: Cardiac Mariners, Inc. (NovaRay Medical, Inc.)
• Inventors: Fiekowsky, Peter J., Solomon, Edward G., Moorman, Jack W., Melen, Robert E., Skillicorn, Brian, Moorhouse, Abigail A., Wilent, deceased, John W.
• Primary Examiner(s): WONG, DON KITSUN
• Application Number:
  US08/421,212
• Time in Patent Office: 1,310 Days
• Field of Search: 378/98.6, 378/98, 378/98.2, 378/98.3, 378/98.8, 378/145, 378/146, 250/368
• US Class Current: 378/98
• CPC Class Codes: A61B 6/06 Diaphragms
• CPC Class Codes: A61B 6/12 Arrangements for detecting or locating foreign bodies
• CPC Class Codes: A61B 6/4028 resulting in acquisition of views from substantially different positions, e.g. EBCT
• CPC Class Codes: A61B 6/4042 K-edge filters
• CPC Class Codes: A61B 6/4241 using energy resolving detectors, e.g. photon counting
• CPC Class Codes: A61B 6/4488 Means for cooling A61B6/045 takes precedence
• CPC Class Codes: A61B 6/482 involving multiple energy imaging
• CPC Class Codes: A61B 90/39 Markers, e.g. radio-opaque or breast lesions markers
• CPC Class Codes: A61M 25/0108 using radio-opaque or ultrasound markers
• CPC Class Codes: G01T 1/20182 Modular detectors, e.g. tiled scintillators or tiled photodiodes stacked detectors G01T1/20181
• CPC Class Codes: G01T 1/20183 Arrangements for preventing or correcting crosstalk, e.g. optical or electrical arrangements for correcting crosstalk
• CPC Class Codes: G01T 1/20185 Coupling means between the photodiode and the scintillator, e.g. optical couplings using adhesives with wavelength-shifting fibres
• CPC Class Codes: G01T 1/202 the detector being a crystal
• CPC Class Codes: G01T 1/2971 using solid state detectors
• CPC Class Codes: G21K 1/025 using multiple collimators, e.g. Bucky screens; other devices for eliminating undesired or dispersed radiation
• CPC Class Codes: H01J 35/147 Spot size control
• CPC Class Codes: H01J 35/153 Spot position control
• CPC Class Codes: H05G 1/10 Power supply arrangements for feeding the X-ray tube supply circuits with converters in general H02M; supply circuits for emitters and amplifiers H04B1/16 - H04B1/1623
• CPC Class Codes: H05G 1/64 Circuit arrangements for X-ray apparatus incorporating image intensifiers
• CPC Class Codes: Y10S 378/901 Computer tomography program or processor

Abstract

An x-ray imaging system according to the present invention comprising a stepped scanning-beam x-ray source and a multi-detector array. The output of the multi-detector array is input to an image reconstruction engine which combines the outputs of the multiple detectors over selected steps of the x-ray beam to generate an x-ray image of the object. A collimating element, preferably in the form of a perforated grid containing an array of apertures, interposed between the x-ray source and an object to be x-rayed. A maneuverable positioner incorporating an x-ray sensitive marker allowing the determination of the precise position coordinates of the maneuverable positioner.

Claims

1. An imaging system comprising an x-ray source, an x-ray detector array, a monitor and a scan generator;

said x-ray source comprising an electron beam generator and an anode;

said anode comprising a target layer which emits x-ray photons when stimulated by a beam of electrons;

said scan generator comprising circuitry for positioning said electron beam in a pattern of steps AP_x by AP_y ;

said x-ray detector array comprising a plurality of detector elements, said detector elements arranged in a DET_x by DET_y array;

said anode and said x-ray detector array positioned such that said target layer emits x-ray photons which strike a plurality of said detector elements of said x-ray detector array;

each of said detector elements comprising means for measuring the intensity of each of said x-ray photons which strike said detector elements and generating an electrical signal indicative of said intensity, said electrical signals from each of said detector elements are discretely output from said x-ray detector array;

a group of discrete electrical outputs is output for each positioning of said electron beam at selected spots on said target layer; and

said monitor comprising processing circuitry which generates an image array based upon said groups of discrete electrical outputs;

said processing circuitry comprising memory which stores the equivalent of a four dimensional array (PIXEL) of size DET_x by DET_y by AP_x by AP_y containing data for each step of said electron beam;

said image array comprising the equivalent of a two dimensional array which has the value;

##EQU14## where focus is a number between 0.1 and 10.0.

2. The imaging system of claim 1 wherein said processing circuitry further comprises a plurality of strings of counters, each of said strings connected to a FIFO register.