Computed tomography breast imaging and biopsy system

Abstract

A prone CT breast x-ray imaging system is described that can image a full breast to create a conventional 2D digital image in very high resolution (e.g. <=25 micron pixels). The system is capable of imaging the entire breast in 3D based on multiple projection views from a 1D or 2D detector. Data can be acquired and reconstructed with a limited number of views from limited angles or with conventional cone beam CT algorithms. The resulting 3D image enables the detection and diagnosis of fine micro calcifications and small masses as may be distributed throughout the breast, thus allowing radiologists to make an improved determination of malignancy as opposed to conventional 2D digital mammography. In addition, the injection of intravenous contrast in conjunction with or without pre and post contrast subtraction imaging provides a radiologist with morphologic information on the existing tumor burden in the breast. This capability may obviate the need for an independent contrast MRI exam of the breast which is increasingly performed for local staging and determination of tumor extent in a patient with a known cancer. Integrated biopsy capability permits convenient and rapid biopsy of any area suspicious for malignancy.

1 . A breast imaging apparatus, comprising:
 a locator for positioning a patient's breast within a predetermined frame of reference having a predetermined axis extending away from a boundary plane of the predetermined frame of reference, wherein an axis of a patient's breast that extends from a patient chest wall through a patient's breast nipple is alignable with said predetermined axis for imaging;   an imaging beam source for transmitting an imaging beam though said predetermined frame of reference;   an imaging signal detector for receiving said imaging beam and providing an output signal in response thereto, wherein at least one of said imaging beam source and said imaging signal detector is movable relative to said predetermined frame of reference, and wherein said apparatus is operable so that said output signal comprises projection image data corresponding with a predetermined angular range of projection views of a patient's breast; and,   a processor for computed tomography processing said projection image data to provide a reconstructed image.   
     
     
         2 . An apparatus as recited in  claim 1 , wherein said locator comprises:
 a table for supporting a patient in a prone position, wherein said table includes at least one aperture for receiving a pendulant patient breast therethrough.   
     
     
         3 . An apparatus as recited in  claim 2 , wherein said table is selectively, vertically positionable. 
     
     
         4 . An apparatus as recited in  claim 1 , wherein said locator comprises:
 a holder for holding a patient's breast in a fixed position within said predetermined frame of reference.   
     
     
         5 . An apparatus as recited in  claim 4 , wherein said holder consists of one of a cup-shaped member for receiving a patient's breast therewithin or a pair of opposing plate members for compressively engaging a patient's breast therebetween. 
     
     
         6 . An apparatus as recited in  claim 5 , further comprising:
 a display for utilizing said image signal to display one or more images of a patient's breast located within said predetermined frame of reference.   
     
     
         7 . An apparatus as recited in  claim 6 , further comprising:
 one of a biopsy device, a surgical device and a treatment device supportable in known relation to said predetermined frame of reference, wherein said display is located to be viewable by a user when operating said one device.   
     
     
         8 . An apparatus as recited in  claim 1 , further comprising:
 a movable, first member for supporting said imaging beam source, wherein said imaging beam source is selectively positionable across a first predetermined angular range relative to said predetermined axis of said predetermined frame of reference.   
     
     
         9 . An apparatus as recited in  claim 8 , wherein said first support member is pivotable about said predetermined axis of said predetermined frame of reference, wherein said imaging beam source is selectively, radially positionable across a first predetermined angular range relative to said predetermined axis of said predetermined frame of reference. 
     
     
         10 . An apparatus as recited in  claim 1 , wherein said imaging beam source and said imaging signal detector are each movable relative to said predetermined frame of reference. 
     
     
         11 . An apparatus as recited in  claim 10 , wherein said imaging beam source and said imaging signal detector are each independently movable relative to said predetermined frame of reference. 
     
     
         12 . An apparatus as recited in  claim 10 , further comprising:
 a movable, first support member for supporting said imaging beam source, wherein said imaging beam source is selectively positionable across a first predetermined angular range relative to said predetermined axis of said predetermined frame of reference.   
     
     
         13 . An apparatus as recited in  claim 12 , further comprising:
 a movable, second support member for supporting said imaging signal detector.   
     
     
         14 . An apparatus as recited in  claim 13 , wherein said first support member and second support member are each independently pivotable about said predetermined axis of said predetermined frame of reference. 
     
     
         15 . An apparatus as recited in  claim 14 , wherein said first support member is pivotable about said predetermined axis of said predetermined frame of reference, wherein said imaging beam source is selectively, radially positionable across a first predetermined angular range relative to said predetermined axis of said predetermined frame of reference, and wherein said imaging signal detector is selectively positionable across a second predetermined angular range relative to said predetermined axis of said predetermined frame of reference. 
     
     
         16 . An apparatus as recited in  claim 15 , wherein said first predetermined angular range and said second predetermined angular range are each ≦270°. 
     
     
         17 . An apparatus as recited in  claim 13 , wherein said imaging beam source is moveable relative to said first support member. 
     
     
         18 . An apparatus as recited in  claim 17 , wherein said imaging beam source is rotatably positionable across a predetermined rotation range relative to said first support member. 
     
     
         19 . An apparatus as recited in  claim 18 , wherein said predetermined rotation range is ≦180°. 
     
     
         20 . An apparatus as recited in  claim 18 , wherein said first support member is pivotable about said predetermined axis of said predetermined frame of reference, and wherein said second support member is pivotably interconnected to said first support member at an adjoinment location offset from said predetermined axis of said predetermined frame of reference. 
     
     
         21 . An apparatus as recited in  claim 20 , wherein said second support member is pivotable about and said imaging beam source is rotatable about a first axis that extends through said adjoinment location and that is parallel to said predetermined axis of said predetermined frame of reference. 
     
     
         22 . An apparatus as recited in  claim 17 , wherein said imaging beam source and said imaging signal detector are disposed for co-rotation about said first axis. 
     
     
         23 . An apparatus as recited in  claim 14 , further comprising:
 at least one automated drive, operatively interconnected to said processor, for automated positioning of said first support member and said second support member to provide a predetermined plurality of projection views within said predetermined angular range.   
     
     
         24 . An apparatus as recited in  claim 1 , wherein said imaging signal detector comprises:
 an array of detector elements, wherein during operation an active array of detector elements is scanned across a region of interest within said predetermined frame of reference, said active array having a length defined by at least one column of aligned detector elements extending parallel to said predetermined axis of said predetermined frame of reference and having a width defined by at least one detector element extending in a direction orthogonal to said length, wherein said width of the active array is less than a width of a patient's breast located within said predetermined frame of reference.   
     
     
         25 . An apparatus as recited in  claim 24 , wherein said array of detector elements is disposed for physical movement relative to said predetermined frame of reference. 
     
     
         26 . An apparatus as recited in  claim 24 , wherein said array of detector elements comprises a plurality of columns of aligned detector elements, and wherein different ones of said columns are activated during operation to define said active array of detector elements. 
     
     
         27 . An apparatus as recited in  claim 1 , wherein said processing includes iteratively generating an estimated image using said projection image data and constraining variation of the estimated image. 
     
     
         28 . An apparatus as recited in  claim 1 , wherein said imaging beam source is located so that a center ray of said imaging beam is one of parallel and divergent relative to said boundary plane. 
     
     
         29 . An apparatus as recited  claim 28 , wherein said imaging beam is a divergent beam. 
     
     
         30 . An apparatus as recited in  claim 29 , wherein said divergent beam is one of a fan shape beam and a cone beam. 
     
     
         31 . An apparatus as recited in  claim 30 , wherein said imaging beam is transmittable through said predetermined frame of reference substantially free from passage through said boundary plane. 
     
     
         32 - 44 . (canceled)