# Patent

## Title
Prostate imaging

## Abstract

A device for registering prostate images, the device comprises an elongate element suitable for insertion into a body passageway, the elongate element comprising at least one marker readable by an ultrasound probe and at least one marker readable by a gamma camera.

## Background
FIELD AND BACKGROUND OF THE INVENTION
The present invention relates to a device and method for registering prostate images, using a registration element suitable for insertion into a body passageway.
The prostate gland may contain multiple tumors that require taking biopsies of multiple tissue samples to determine, for example, the presence of malignant cells.
During prostate biopsy, an ultrasound probe is inserted into the patient rectum to produce ultrasound images of the prostate. A thin biopsy needle is inserted, for example trans-rectally, and visualized on the ultrasound monitor. The multiple random tissue samples taken with the biopsy needle are sent to a laboratory and analyzed for malignant cells.
To take multiple samples on a non-random basis, nuclear images of the prostate taken from a nuclear imager mounted on a large gantry in close proximity to the surgical field are registered with the ultrasound images.
SUMMARY OF THE INVENTION
According to one aspect of the invention, there is provided a device for registering prostate images, the device comprising: an elongate element suitable for insertion into a body passageway, the elongate element comprising at least one marker readable by an ultrasound probe, and at least one marker readable by a gamma camera.
In embodiments, the elongate element is configured for insertion into a portion of a urethra. In embodiments, the elongate element is flexible.
In embodiments, the at least one marker readable by the ultrasound probe comprises at least one of: air bubbles and solid-state markers.
In embodiments, the at least one marker readable by the ultrasound probe has a different density than the average density of prostate tissue.
In embodiments, the elongate element is provided in a kit containing a tumor imaging fluid and the at least one marker readable by the gamma camera has a photo peak energy that is different from a photo peak energy of the tumor imaging fluid.
In embodiments, the at least one marker readable by an ultrasound probe comprises at least two markers readable by the ultrasound probe and the at least one marker readable by the gamma camera is configured as an interleaf between the at least two of the markers readable by the ultrasound probe.
In embodiments, the device includes at least three interleafs along at least a portion of the elongate element, comprising: at least one first interleaf pattern, at least one second interleaf pattern, and at least one third interleaf pattern.
In embodiments, the at least one first interleaf is spaced a first distance from the at least one second interleaf, and the at least one second interleaf is spaced a second distance from the at least one third interleaf, wherein the first distance is different from the second distance.
In embodiments, the device includes at least two markers readable by the gamma camera, comprising at least one first marker readable by the gamma camera having a different photo peak energy than the at least one second marker readable by the gamma camera.
In embodiments, the device includes at least two markers readable by the ultrasound probe, comprising a first marker having a first density readable by the ultrasound probe and a second marker having a second density readable by the ultrasound probe.
In embodiments, the device includes at least one marker that is readable by the ultrasound probe and the gamma camera.
In embodiments, the device includes at least two markers that are readable by the ultrasound probe and the gamma camera, comprising at least one first marker having a first photo peak energy and at least one second marker having a second photo peak energy.
In embodiments, the device includes at least two markers that are readable by the ultrasound probe and the gamma camera, comprising at least one first marker having a first density readable by the ultrasound probe and at least one second marker having a second density readable by the ultrasound probe.
According to a further aspect of the invention, there is provided a method for registering an ultrasound image with a gamma camera image, the method comprising: imaging a tissue portion and an ultrasound-readable marker using a rectally introduced ultrasound probe, imaging the tissue, and a gamma camera-readable marker using a rectally introduced gamma camera, and registering the image using the ultrasound probe and the image using the gamma camera.
In embodiments, the method includes providing the ultrasound-readable marker and the gamma camera-readable marker on a single elongate element.
In embodiments, the tissue portion comprises a prostate.
In embodiments, the method includes superimposing a 2D slice of the imaging using the gamma camera on a correspondingly registered 2D slice of the imaging using the ultrasound.
In embodiments, the method includes guiding a biopsy needle seen on an ultrasound image with the superimposed 2D slice.
According to another embodiment of the invention, there is provided an image registration device, comprising: a correlating circuit configured to correlate a 2D ultrasound image of a tissue portion to a 3D ultrasound image of the tissue portion and a nuclear extraction circuit configured to extract a 2D nuclear image from a 3D nuclear image of the tissue portion, based on the correlation.
In embodiments, the circuitry is programmed using software. In embodiments, the circuitry is preprogrammed with software.
In embodiments, the circuitry is configured to extract the 2D nuclear image using at least two markers, comprising at least one ultrasound-readable marker, and at least one gamma camera-readable marker.
In embodiments, the circuitry is configured to assemble the 3D ultrasound image from multiple 2D ultrasound images of the tissue portion.
In embodiments, the circuitry includes an image generating software module configured to generate a real time image of the correlated 2D ultrasound image and the 2D extracted nuclear image.
The present invention successfully addresses the shortcomings of the presently known configurations by providing a device and method for registering prostate images using a registration element suitable for insertion into a body passageway.
Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, suitable methods and materials are described below.
In case of conflict, the patent specification, including definitions, will control. In addition, the materials, methods, and examples are illustrative only and not intended to be limiting.
As used herein, the terms “comprising” and “including” or grammatical variants thereof are to be taken as specifying the stated features, integers, steps or components but do not preclude the addition of one or more additional features, integers, steps, components or groups thereof. This term encompasses the terms “consisting of” and “consisting essentially of”.
The phrase “consisting essentially of” or grammatical variants thereof when used herein are to be taken as specifying the stated features, integers, steps or components but do not preclude the addition of one or more additional features, integers, steps, components or groups thereof but only if the additional features, integers, steps, components or groups thereof do not materially alter the basic and novel characteristics of the claimed composition, device or method.
The term “method” refers to manners, means, techniques and procedures for accomplishing a given task including, but not limited to, those manners, means, techniques and procedures either known to, or readily developed from known manners, means, techniques and procedures by practitioners of the imaging arts.
Implementation of the method and/or system of embodiments of the invention can involve performing or completing selected tasks manually, automatically, or a combination thereof. Moreover, according to actual instrumentation and equipment of embodiments of the method and/or system of the invention, several selected tasks could be implemented by hardware, by software or by firmware or by a combination thereof using an operating system.
For example, hardware for performing selected tasks according to embodiments of the invention could be implemented as a chip or a circuit.
Additionally, software for performing selected tasks according to embodiments of the invention could be implemented as a plurality of software instructions being executed by a computer using any suitable operating system.
In an exemplary embodiment of the invention, one or more tasks according to exemplary embodiments of method and/or system as described herein are performed by a data processor, such as a computing platform for executing a plurality of instructions. Optionally, the data processor includes a volatile memory for storing instructions and/or data and/or a non-volatile storage, for example, a magnetic hard disk and/or removable media, for storing instructions and/or data.
Optionally, a network connection is provided as well. A display and/or a user input device such as a keyboard or mouse are optionally provided as well.



BRIEF DESCRIPTION OF THE DRAWINGS
The file of this patent contains at least one drawing executed in color photograph. Copies of this patent with color photograph(s) will be provided by the Patent and Trademark Office upon request and payment of necessary fee.
The invention of a device and method for registering prostate images, using a registration element suitable for insertion into a body passageway, is herein described, by way of example only, with reference to the accompanying drawings.
With specific reference now to the drawings in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of the preferred embodiments of the present invention only, and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the invention.
In this regard, no attempt is made to show structural details of the invention in more detail than is necessary for a fundamental understanding of the invention; the description taken with the drawings making apparent to those skilled in the art how the several forms of the invention may be embodied in practice.
In the drawings:
FIG. 1 shows a registration guide, according to an embodiment of the present invention;
FIGS. 2 and 3 show a gamma camera probe being used to examine a prostate in a cross section of a human body, according to an embodiment of the present invention;
FIG. 4A shows the prostate of FIG. 2 being examined with an ultrasound probe, according to an embodiment of the present invention;
FIG. 4B shows registration of the ultrasound image of FIG. 4A and gamma camera image of FIG. 2, according to an embodiment of the present invention;
FIG. 5 shows biopsies being taken in real time using the registered image of FIG. 4B, according to an embodiment of the present invention; and
FIG. 6 shows a Prostate Image Registration Flowchart according to an embodiment of the present invention.



DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention is a device and method for providing registration of nuclear and ultrasound images of the prostate in real time.
The principles and operation of the device and method according to the present invention may be better understood with reference to the drawings and accompanying descriptions.
Before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of the components set forth in the following description or illustrated in the drawings.
Further, it is to be understood that the invention is not limited in its application to the details set forth in the following description. The invention is capable of other embodiments or of being practiced or carried out in various ways.
In addition, it is to be understood that the phraseology and terminology employed herein is for the purpose of description and should not be regarded as limiting.
Referring now to the drawings:
FIG. 1 shows a registration guide 104 for the registration of ultrasound and nuclear isotope images of prostate tissue 122.
Registration guide 104 comprises a flexible polymer that can easily follow the configuration of a urethra 110 and a diameter that allows easy insertion through urethra 110, for example between about 2.0 and 4.0 millimeters in diameter.
Registration guide 104 includes a nuclear isotope that emits gamma rays that is formed into nuclear imager-readable markers 106. Nuclear imager-readable markers 106 can be formed, for example, by introducing particles of the nuclear isotope into a base comprising a polymer, which is then adhered to registration guide 104.
Nuclear imager-readable markers 106 emit gamma rays having a photo-peak energy that is different from an average photo-peak energy that of an isotope 101 that is introduced by injection. In embodiments, isotope 101 may be introduced as a sub-dermal and/or intra-muscular injection.
In alternative embodiments, isotope 101 may be introduced through vena-puncture. In still other embodiments, isotope 101 may be directly injected into prostate tissue 122 surrounding registration guide 104.
Registration guide 104 additionally includes ultrasound-readable markers 105 comprising air bubbles or solid-state markers that are configured to reflect ultrasound waves.
In embodiments, one or more ultrasound-readable markers have a density that is different from the density of urethra 110 and prostate tissue 122 surrounding registration guide 104. As explained below, there are varieties of arrangements of ultrasound-readable markers 105 and/or nuclear markers 106 on registration guide 104 for the purpose of providing, for example, greater registration precision.
Ultrasound-readable markers 105 and nuclear markers 106 are optionally placed on registration guide 104 to be read by the respective imaging devices from any degree of rotation with respect to registration guide 104.
Referring to FIGS. 2 and 3, prostate isotope 101 has been introduced via the blood stream and absorbed by prostate 122 shown in a cross section of a portion of a human 120.
Registration guide 104, of sufficient length to pass through urethra 110 and prostate 122, is positioned so that ultrasound-readable markers 105 and nuclear imager-readable markers 106 are near prostate 122. A nuclear imager camera probe 102 is placed in a rectum 103 and an image 124 of prostate 122 is acquired and displayed on a monitor 125.
In some cases, it may be advantageous to prevent longitudinal movement of registration guide 104 within urethra 110. In such cases, registration guide 104 optionally includes a balloon at a first end that is inflatable within the bladder and/or a biologically compatible tape that secures a second end of registration guide 104 to the external opening of urethra 110.
Referring to FIG. 4A, nuclear imager camera probe 102 has been replaced by an ultrasound probe 109 in rectum 103.
An ultrasound scan of prostate 122 is made, thereby capturing a long section of registration guide 104, forming an image slice 126 that is displayed on monitor 125. Multiple image slices 126 are formed into a 3D ultrasound image as will be explained below.
In general, the position of nuclear imager camera probe 102 and ultrasound probe 109 are determined by the position of registration guide 104 within the respective images. For example, a portion of registration guide 104 appears in the bottom left corner of an image provided by nuclear imager camera probe 102. The same portion of registration guide 104 appears in the upper right corner of an image provided by ultrasound probe 109. Registration guides in the ultrasound and nuclear images are aligned during processing so that appropriate portions of each image undergo registration.
Optionally, registration guide 104 is a relatively non-stretchable material so that the spacing between ultrasound-readable markers 105 and nuclear imager-readable markers 106 does not significantly change between acquiring images from nuclear imager camera probe 102 and ultrasound probe 109.
Alignment between images from nuclear imager camera probe 102 and ultrasound probe 109 may be optionally enhanced by varying the spacing and/or pattern of ultrasound-readable markers 105 and nuclear imager-readable markers 106.
Registration guide 104 is shown with single ultrasound-readable markers 105 equally spaced between and single nuclear markers 106 that can require capturing a long section of registration guide 104 to provide a basis for image registration.
A greater number of markers 105 and 106 along a given length of registration guide 104 provides for more precise location of images provided by nuclear imager camera probe 102 and/or ultrasound probe 109.
Alternatively, applying groups of markers 105 and 106 and varying parameters of markers 105 and 106 in each group, may allow the operator to more precisely identify the location of each image based upon the positioning of each group of markers.
Variations in parameters may include multiple ultrasound-readable markers 105 that vary in density throughout the length of registration guide 104. Additionally or alternatively, by using different isotopes, multiple nuclear markers 106 may vary in photo-peak throughout registration guide 104, similarly achieving greater imaging precision such that a relatively small field of the imaged portion of prostate 122 can be precisely determined.
Alternatively, to achieve registration precision along a relatively short portion of registration guide 104, ultrasound-readable markers 105 that vary in density and nuclear markers 106 having unvaried photo-peaks may be merged into single markers 105 and 106, thereby providing more precise positioning information.
In still further optional configurations, multiple nuclear markers 106 varying in photo-peak can be merged with ultrasound-readable markers 105.
In still further embodiments, single markers 105 and 106 having variable ultrasound density can be spaced relatively close together.
In still further embodiments to achieve greater positioning precision, ultrasound-readable markers 105 and nuclear markers 106 may be sequenced to form patterns.
For example, an upper portion of registration guide 104 includes two ultrasound-readable markers 105 followed by one nuclear marker 106. Along a mid portion of registration guide 104, two nuclear markers 106 follow one ultrasound-readable marker 105. Along a lower portion of registration guide 104, one nuclear marker 106 is followed by one ultrasound-readable marker 105.
In still further embodiments, variable distances between the markers may be used as a code to support absolute positioning based on relatively short segment of the registration guide.
For example, along an upper portion of registration guide 104, ultrasound-readable markers 105 and nuclear markers 106 are spaced 1 millimeter apart. Along a mid portion of registration guide 104, markers 105 and 106 are spaced 1.5 millimeters apart, while along a lower portion of registration guide 104, markers 105 and 106 are spaced 2.0 millimeters apart.
Referring to FIG. 4B, as seen in image 128, a slice of ultrasound image slice 126 is registered with nuclear image 124, using registration guide 104 to align the images as noted above. Registered image 128 is displayed on monitor 125 in which nuclear markers 106 and acoustical markers 105 have been aligned, merged and then deleted from image 128. Tumors 129, 130, 132 and 134 are shown on ultrasound image 126.
In FIG. 5, registered image 128 is used to visualize the position of biopsy needle 144 in real time and tissue samples are precisely taken from tumors 129, 130, 132 and 134.
FIG. 6 shows a Prostate Image Registration Flowchart 100, which summarizes the steps used in registering the above-noted ultrasound and nuclear images.
Isotope 101 has already been introduced into the patient and has bound to prostate tissue 122 and, with higher density, to prostate tumors 129 and 130.
Beginning at an insert stage 102, registration guide 104 is inserted into the urethra of the patient proximate to prostate 122.
At stage 111, a nuclear camera probe is inserted into rectum 103, and a nuclear image of prostate 122 is acquired. Included in the 3D nuclear image are the images of the above-noted nuclear markers on registration guide 104. The nuclear 3D image is saved for later use and the nuclear camera probe is removed.
At an ultrasound 3D image stage 112, ultrasound probe is inserted into rectum 103 and moved with respect to prostate 122. As the clinician moves the ultrasound probe, position and orientation are recorded with respect to registration guide 104 while a series of 2D ultrasound images are recorded.
These 2D slices, together with the information about their positions and orientations, are formed into an ultrasound 3D image of prostate 122 at ultrasound 3D image stage 112. The captured 3D ultrasound prostate image is saved for later use.
In an image registration stage 113, the 3D nuclear image is registered with the ultrasound 3D image of prostate 122. The registration process registers ultrasound and nuclear images by aligning the appropriate markers on registration guide 104 and a common coordinate system 148 is created for both the ultrasound and nuclear 3D images.
At an optional stage 114, using common image processing methods, the tumors 129 and 130, having higher signal than the background, are distinguished from the background. The background is then deleted from the image. An image of the tumors only, with the registration coordinate system, is saved for a later use.
At an ultrasound 2D stage 115, a real time ultrasound 2D image 126 is taken of the prostate. At a stage 116 the ultrasound 2D image 126 is compared and correlated with the 3D ultrasound image 122 acquired in step 112.
In embodiments, identification of the 2D ultrasound image 126 within the 3D ultrasound image 122 uses a cross correlation method, a feature correlation method, or other methods that may be available in the future.
The location of 2D image 126 is then identified in the common coordinate system 148.
At a stage 117, using the planar information found for 2D image 126 in stage 116 and common coordinate system 148, a correlated 2D slice 150 is extracted from the 3D image saved in stage 114.
In a stage 118, the ultrasound 2D image 126 and the nuclear 2D image 150 are registered using the common coordinate system 148 and displayed on a monitor that includes the real time ultrasound 2D view 126 showing biopsy needle 144 in position with the correlated nuclear 2D view 150 of tumor 129.
Biopsy needle 144, as shown, is entered trans-rectally, however trans-peritoneum or other entry positions are contemplated as well.
It is expected that during the life of this patent, many relevant ultrasound and gamma camera registration systems will be developed and the scope of the term “ultrasound and gamma camera registration systems” is intended to include all such new technologies a priori.
As used herein the term “about” refers to ±10%.
Additional objects, advantages, and novel features of the present invention will become apparent to one ordinarily skilled in the art upon examination of the following examples, which are not intended to be limiting. Additionally, each of the various embodiments and aspects of the present invention as delineated hereinabove and as claimed in the claims section below finds experimental support in the following examples.
It is appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable subcombination.
Although the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art.
Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims. All publications, patents and patent applications mentioned in this specification are herein incorporated in their entirety by reference into the specification, to the same extent as if each individual publication, patent or patent application was specifically and individually indicated to be incorporated herein by reference. In addition, citation or identification of any reference in this application shall not be construed as an admission that such reference is available as prior art to the present invention.

## Claims

1. A device for assisting in registering prostate images, the device comprising:
an elongate element suitable to follow configuration of a urethra and having a diameter and length allowing insertion into and passing through said urethra to a position near the prostate, said elongate element comprising: i) at least one marker readable by an ultrasound probe, and
ii) at least one marker readable by a gamma camera;
wherein said markers and same portions of said elongate element imaged in ultrasound and gamma camera images of the prostate are configured to be aligned in an image registration process.

2. The device according to claim 1, wherein said elongate element is flexible.

3. The device according to claim 1, wherein said at least one marker readable by said ultrasound probe comprises at least one of:
an air bubble; and
a solid state marker.

4. The device according to claim 1, wherein said at least one marker readable by said ultrasound probe has a different density than an average density of prostate tissue.

5. The device according to claim 1, wherein said elongate element is provided in a kit containing a tumor imaging fluid and said at least one marker readable by said gamma camera has a photo peak energy that is different from a photo peak energy of said tumor imaging fluid.

6. The device according to claim 1, wherein;
i) said at least one marker readable by an ultrasound probe comprises at least two markers readable by said ultrasound probe; and
ii) said at least one marker readable by said gamma camera is configured as an interleaf between said at least two of said markers readable by said ultrasound probe.

7. The device according to claim 6, including at least three interleafs along at least a portion of said elongate element, comprising:
at least one first interleaf pattern;
at least one second interleaf pattern; and
at least one third interleaf pattern.

8. The device according to claim 7, wherein:
i) said at least one first interleaf is spaced a first distance from said at least one second interleaf; and
ii) said at least one second interleaf is spaced a second distance from said at least one third interleaf.

9. The device according to claim 1, including at least two markers readable by said gamma camera, comprising:
i) at least one first marker having a first photo peak energy; and
ii) at least one second marker having a second photo peak energy.

10. The device according to claim 1, including at least two markers readable by said ultrasound probe, comprising:
i) a first marker having a first density readable by said ultrasound probe; and
ii) a second marker having a second density readable by said ultrasound probe.

11. The device according to claim 1, including at least one marker that is readable by said ultrasound probe and said gamma camera.

12. The device according to claim 1, including at least two markers that are readable by said ultrasound probe and said gamma camera, comprising:
i) at least one first marker having a first photo peak energy; and
ii) at least one second marker having a second photo peak energy.

13. The device according to claim 1, including at least two markers that are readable by said ultrasound probe and said gamma camera, comprising:
i) at least one first marker having a first density readable by said ultrasound probe; and
ii) at least one second marker having a second density readable by said ultrasound probe.

14. The device of claim 1, wherein said elongate element includes an inflatable balloon at a first end thereof.

15. The device of claim 1, wherein said at least one marker readable by said ultrasound probe and said at least one marker readable by said gamma camera along said elongate element are variably spaced apart or patterned.

16. The device of claim 1,
wherein along a length of said elongate element at least one said ultrasound probe marker is spaced a distance apart from at least one said gamma camera marker.

17. The device of claim 1, wherein said aligned imaged markers and imaged same portions of said elongate element are used for creating a common coordinate system for said ultrasound and gamma camera images of the prostate.

18. The device of claim 1, wherein the device is used for assisting in acquiring the prostate images.

19. The device of claim 18, wherein a position of said same portions of said elongate element imaged in said ultrasound and gamma camera images of the prostate determines a position of said ultrasound probe and of said gamma camera relative to the prostate.

20. A method for assisting in registering prostate images, the method comprising:
providing an elongate element suitable to follow configuration of a urethra and having a diameter and length allowing insertion into and passing through said urethra to a position near the prostate, said elongate element comprising: i) at least one marker readable by an ultrasound probe, and ii) at least one marker readable by a gamma camera;
inserting said elongate element into and through said urethra to a said position near the prostate;
acquiring ultrasound images and gamma camera images of the prostate and of said markers, by said ultrasound probe and said gamma camera; and
aligning said markers and same portions of said elongate element imaged in said ultrasound and gamma camera images of the prostate, in an image registration process.

21. The method of claim 20, further comprising using said aligned imaged markers and imaged same portions of said elongate element for creating a common coordinate system for said ultrasound and gamma camera images of the prostate.

22. The method of claim 20, further comprising using a position of said same portions of said elongate element imaged in said ultrasound and gamma camera images of the prostate for determining a position of said ultrasound probe and of said gamma camera relative to the prostate.