MAMMOGRAPHY SYSTEM AND METHOD EMPLOYING OFFSET COMPRESSION PADDLES, AUTOMATIC COLLIMATION, AND RETRACTABLE ANTI-SCATTER GRID
A mammographic imaging system is optimized for use with a single fixed size flat panel digital image receptor. It accommodates compression devices (paddles) of varying sizes, and positions them properly in a field of view of the image receptor. When a compression paddle with size smaller than the field of view of the image receptor is used the compression paddle can be shifted laterally in the direction parallel to the chest wall, so as to facilitate different views of different size breasts, and permit the image receptor to image as much of the desired tissue as possible. An automatic X-ray collimator restricts the X-ray illumination of the breast in accordance with the compression paddle size and location in the field of view. An anti-scatter grid, mounted inside the image receptor enclosure, just below the top cover of the enclosure, can be retracted out of the field of view of the image receptor for use in magnification imaging.
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This application is a continuation application and claims priority under 35 U.S.C. §120 to U.S. patent application Ser. No. 13/190,989, filed Jul. 26, 2011, which is a continuation of U.S. Pat. No. 7,986,765, filed on Feb. 22, 2010, which is a continuation of U.S. Pat. No. 7,688,940, filed on May 8, 2009, which is a continuation of U.S. Pat. No. 7,609,806, filed Jan. 15, 2008, which is a continuation of U.S. Pat. No. 7,319,735, filed Nov. 30, 2006, which is a continuation of U.S. Pat. No. 7,443,949, filed Oct. 18, 2004, which is a Section 371 national stage of International Application No. PCT/US02/33058, filed, Oct. 17, 2002, claiming the benefit of U.S. Provisional application No. 60/350,213, filed Oct. 19, 2001. Each of the above applications is hereby incorporated by reference.
BACKGROUNDX-Ray mammography machines typically use an x-ray source mounted at one end of a rotatable c-arm assembly and an image receptor at the other. Between the x-ray source and the image receptor is a device for compressing and immobilizing a breast. Until recently, the image receptor was typically a screen-film (s/f) cassette, which generated an image related to the detected transmission of x-rays through the breast. These s/f cassettes typically conic in standard sizes, e.g., 18 cm×24 cm (small) and 24 cm×30 cm (large), with the large cassette used when the breast is too large to be uniformly compressed by the small cassette. The cassettes are easily attachable and removable from a breast support tray of a conventional mammography system. The device for compressing the breast is often called a paddle, and comes in a variety of sizes to match both the cassette size and the breast size. Such matching is desirable because the use of a small size paddle on a large breast can result in uneven and inadequate breast compression and may not allow full-breast imaging, which using a large paddle on a small breast can impede access to the breast, which is important during the compression cycle in order to optimize the amount of breast tissue brought into the field of view of the image receptor.
New mammography systems are now being developed to use digital image receptors as replacements for the screen-film cassettes. These digital image receptors, sometimes called flat panel receptors, or that panel digital x-ray receptors, are different in many ways from s/f cassettes. They have many advantages, but also tend to be heavier and somewhat thicker. Typically, they are not designed to be removable in normal use, so a system normally will employ only one size image receptor. These characteristics can present challenges for some imaging procedures and breast sizes, particularly for the mediolateral oblique view (MLO) taken as a part of typical breast x-ray imaging. As with screen-film systems, it is still advantageous to use a compression paddle that matches the breast size. This typically means that the compression paddles will be removable, and there will be a selection of paddle sizes available with the system.
A number of x-ray protocols have been used for breast imaging. One common view is the cranio-caudal (CC) view, illustrated in
To applicants' knowledge, these and other issues regarding compression paddle use with flat panel digital receptors in mammography have not been solved and perhaps have not been even addressed. In a different setting, it has been proposed to move a compression paddle laterally, relative to the proximal edge of the screen-film cassette, but for the different purposes of aligning a cutout in the paddle with a particular portion of the breast. See U.S. Pat. No. 5,199,056. This is believed to require a paddle larger that would normally be used for the breast size so as to maintain even compression when the cutout is off-center relative to the breast. Other earlier proposals are known for features such as collimation that adjusts to film cassette size, source-to-image distance and/or cross-sectional area to be imaged (U.S. Pat. Nos. 3,502,878, 3,863,073, 5,627,869, and 6,149,301), moving a paddle (U.S. Pat. No. 3,971,950), moving a cassette (U.S. Pat. No. 4,989,227), and retracting a cassette holder (U.S. Pat. No. 4,559,641). The cited patents are hereby incorporated by reference in this patent specification.
SUMMARYAn object of the disclosed system and method is to provide mammography that overcomes known disadvantages of proposals involving the otherwise desirable use of flat panel, digital x-ray receptors.
Another object is to employ compression paddles that match both the size and position of the patient's breast relative to the proximal edge of a digital x-ray image receptor so as to improve image quality, patient comfort and the ability of the health professional to position the breast optimally for imaging.
Another is to provide automated collimation control that changes x-ray beam collimation in accordance with one or more of the size and position of the compression paddle and of the breast, and the position of a breast platform relative to the receptor, preferably in response to information that is automatically sensed.
Another is to provide x-ray exposure control that is responsive to at least one of the size and position of the compression paddle, the position of the breast, and a pre-exposure x-ray measurement, preferably in response to information that is automatically sensed.
Another is to provide a scatter-suppression grid that is retracted for image magnification protocols, preferably automatically in response to sensing a breast position for magnification imaging.
These and other objects are met in a non-limiting example comprising a mammography system having a flat panel digital x-ray receptor, an x-ray source selectively emitting a collimated x-ray beam toward the receptor, and a compression paddle of a selectable size mounted for selective movement at least along a proximal edge of the x-ray receptor as well as along the x-ray beam. At least for selected breast x-ray protocols, a patient's breast is positioned off-center relative to the proximal edge of the x-ray receptor, and paddle of an appropriate size also is positioned off-center relative the same proximal edge to compress the breast for x-ray imaging.
In addition, the system includes one or more of a number of other features. An exposure control can be responsive to information regarding breast thickness along the beam direction to control x-ray exposure for imaging. This information can come from a conventional auto-exposure sensor (AES) resulting from a pre-exposure, low-dose firing of the x-ray source from an output of the digital x-ray receptor during such pre-exposure firing, and/or from sensors for the relative positions of the x-ray source, the x-ray receptor, the compression paddle and/or the breast tray. The system can include a collimation control responsive to information regarding one or more of the size of the paddle, its location along the beam, its location relative to the proximal edge of the receptor, a desired field of view, magnification parameters, and the like. This information can come from appropriate sensors and/or can be input by the health professional carrying out imaging. The system can include a scatter-suppressing grid selectively movable between a position in the path of the imaging beam and a position outside that path (for magnification imaging). Again, information for controlling grid position can come from one or more different sources. And, the system can include a built-in or a separate viewing station receiving x-ray image information from the x-ray receptor and possibly from some or all of the sensors, processing it, and displaying the results as an image and/or in others forms.
Referring to
In use for a CC view, paddle 2 and its supporting arm 6 are moved up, breast 3 is positioned on tray 11 and compressed by bringing paddle 2 down as needed. With suitable collimation by collimators 40 (which typically collimate in two directions, of which only one is illustrated in
Referring to
It should be clear that many other arrangements and variations will be apparent to persons skilled in the technology based on the disclosure in this patent specification and that the above embodiments are only some of examples embodying inventions whose scope is defined by the appended claims.
Claims
1.-19. (canceled)
20. A system comprising:
- an x-ray source configured to move during an imaging procedure;
- an x-ray receptor configured to obtain images during the imaging procedure;
- a paddle for compressing a breast during the imaging procedure;
- a collimator configured to control dispersion of radiation from the x-ray source; and
- an auto-collimation control for automatically controlling the collimator, wherein the auto-collimation control is configured to receive an input signal.
21. The system of claim 20, further comprising a sensor to send the input signal to the auto-collimation control, wherein the sensor is configured to detect at least one of:
- a position of the paddle relative to a proximal edge of the x-ray receptor;
- a size of the paddle; and
- a position of the paddle along a beam emitted from the x-ray source.
22. The system of claim 20, further comprising a sensor to send the input signal to the auto-collimation control, wherein the sensor is configured to detect at least one of:
- a field of view;
- a magnification parameter; and
- a setting of the collimator.
23. The system of claim 20, further comprising a sensor to send the input signal to the auto-collimation control, wherein the sensor is configured to detect at least one of:
- a position of a breast relative to the receptor; and
- a position of an anti-scatter grid disposed between the x-ray source and the x-ray receptor.
24. The system of claim 20, wherein the input signal is received from at least one of an auto-exposure sensor and the x-ray receptor.
25. The system of claim 24, wherein the input signal is received based on a pre-exposure firing of the x-ray source.
26. The system of claim 20, wherein the auto-collimation control is configured to, at least one of, (a) automatically move the collimator and (b) automatically adjust the collimator so as to control a collimation of a beam emitted from the x-ray source.
27. The system of claim 26, wherein the auto-collimation control is configured to automatically adjust the collimator so as to control a collimation of a beam emitted from the x-ray source, wherein the automatic adjustment confines a beam emitted from the x-ray source to a predetermined footprint.
28. The system of claim 20, further comprising a sensor configured to send the input signal.
29. A method of automatically controlling an imaging system comprising an x-ray source, an x-ray receptor, a paddle, and a collimator, the method comprising:
- receiving, at an auto-collimation control system, an input signal from a sensor; and
- performing at least one of: (a) automatically moving the collimator and (b) automatically adjusting the collimator so as to control a collimation of a beam emitted from the x-ray source.
30. The method of claim 29, further comprising:
- emitting a beam from the x-ray source; and
- sending the input signal, prior to the performing operation.
31. The method of claim 30, wherein the beam comprises a pre-exposure firing.
32. The method of claim 29, further comprising detecting, with the sensor, information regarding a breast disposed in a field of view of the x-ray receptor.
33. The method of claim 29, further comprising detecting, with the sensor, at least one of:
- a position of the paddle relative to a proximal edge of the x-ray receptor;
- a size of the paddle; and
- a position of the paddle along a beam emitted from the x-ray source.
34. The method of claim 29, further comprising detecting, with the sensor, at least one of:
- a field of view;
- a magnification parameter; and
- a setting of the collimator.
35. The method of claim 29, further comprising detecting, with the sensor, at least one of:
- a position of a breast relative to the receptor; and
- a position of an anti-scatter grid disposed between the x-ray source and the x-ray receptor.
36. The method of claim 29, wherein the performing operation comprises automatically adjusting the collimator so as to control a collimation of a beam emitted from the x-ray source, wherein the automatic adjustment operation confines a beam emitted from the x-ray source to a predetermined footprint.
37. A method of automatically controlling an imaging system comprising an x-ray source, an x-ray receptor, a paddle, a collimator, and a collimator control, the method comprising:
- emitting a beam from the x-ray source;
- receiving, at the collimator control, a signal; and
- automatically adjusting the collimator prior to emitting a subsequent beam from the x-ray source.
38. The method of claim 37, wherein the automatically adjusting operation comprises moving the collimator.
39. The method of claim 37, wherein the automatically adjusting operation comprises confining a subsequent beam emitted from the x-ray source to a predetermined footprint.
Type: Application
Filed: Jan 13, 2015
Publication Date: Jul 9, 2015
Applicant: Hologic, Inc. (Bedford, MA)
Inventors: Kenneth DEFREITAS (Patterson, NY), Anthony PELLEGRINO (New Fairfield, CT), Thomas A. FARBIZIO (Newtown, CT), Roman JANER (Commerce Township, MI), Georgia HITZKE (Boston, MA)
Application Number: 14/595,826