Abstract:
Apparatus for providing image registration of a target, comprising a gamma camera that acquires a nuclear image of said target, an optical imager in a fixed or known relationship with respect to said gamma camera that acquires an optical image of said target and an image registrator operative to receive and register said nuclear image and said optical image.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates to nuclear image registration.  
         BACKGROUND OF THE INVENTION  
         [0002]    Image registration of two images, such as X-ray and nuclear images of internal human anatomy, provide visualization of cancerous nodes and surrounding organ structure. However, to make an initial incision that properly encompasses the cancerous nodes, the surgeon often relies upon estimating the node location in relation to the skin. The resultant incision, for example, is often imprecise and/or of improper length or configuration, requiring modification after the surgical area is exposed so the cancerous nodes can be properly removed.  
           [0003]    Incision location and configuration are extremely important. For example, an incision that improperly traverses a joint may result in long recuperation, poor joint function and/or loss of extremity use. Recognizing this problem, the surgeon may place radiopaque markers on the skin, for example fixed wires or paint that appear in the registered radiographic image.  
           [0004]    Balan, et al. in WO 00/75691 A1, the disclosure of which is incorporated herein by reference, present an apparatus for providing scans from a gamma camera and tomographic imager of a target.  
           [0005]    Lemchen in U.S. Pat. No. 6,081,739 demonstrates a method for using video surface scanning, 3D surface reconstruction and X-ray for visualizing the position of teeth versus the lips, cheeks and facial features.  
         SUMMARY OF THE INVENTION  
         [0006]    An aspect of some embodiments of the present invention relates to registering a nuclear image of a target on or within a tissue, for example a tumor and/or its sentinel nodes, with an optical image of the skin of the target, to provide a registered image that guides a surgeon in planning and executing an incision. An incision based upon a registered image from nuclear and optical images encompasses the tumor and nodes without undue extension and/or damage to adjacent tissue.  
           [0007]    The registered image includes, for example, specific anatomical landmarks such as breast position, bone protrusion or position, hair, birthmarks, scars and/or tattoos to aid the surgeon in planning the incision. Additionally or alternatively, the skin is marked with markers that show in the optical image and are registered with the nuclear image to provide a registered image with markings that aid in planning the incision.  
           [0008]    Optionally, the skin is marked with radiopaque markings that show up as fiduciary markings in the optical image and as radioactive markings in the nuclear image. In an embodiment of the invention, the fiduciary markings on the optical image are aligned with the radioactive markers on the nuclear image by an operator who superimposes the two images to provide a registered image. Additionally or alternatively, registration of the two images is provided by an image registrator that aligns the radioactive markings in the nuclear image with the fiduciary markings in the optical image.  
           [0009]    In an exemplary embodiment of the present invention, an optical imager, for example a photographic digital camera that provides at least still views, and a gamma camera, are mounted on a gantry. The optical imager is focused on the external surface of a patient and precisely aligned with the gamma camera to automatically provide a registered image. In some embodiments, the camera is not mounted upon the gantry but upon an arm that moves in measurable relationship to the gantry.  
           [0010]    Optionally, the gantry includes an X-ray imager that registers an X-ray image along with the nuclear and optical registered images, to provide, for example, a registered image that provides further information on the target. In some embodiments, an X-ray image comprises a planer radiographic image. In some embodiments, an X-ray image comprises a digital planer radiographic image. Additionally or alternatively, an X-ray image comprises an X-ray tomographic image.  
           [0011]    In an embodiment of the present invention, the registered image including an optical image, and optionally a nuclear and/or X-ray image, is provided as a picture, for example as a hard copy. Additionally or alternatively, the registered image is projected by a projector onto a projection site, for example, located in the operating theater.  
           [0012]    In an embodiment of the invention, the registered image is shown on a viewing station, for example, located in the operating theater. In an embodiment of the invention, controls are provided on the viewing station to allow an operator to outline an incision directly on the viewing station registered image. Optionally, controls are provided to vary the relative intensity of image components, for example anatomic features, so the tumor and/or incision, for example, are seen clearly and distracting aspects of the registered image removed.  
           [0013]    Optionally, controls are provided to vary the relative intensity of radioactive image components, so the tumor, tumor nodes and/or radioactive markers are seen clearly in relation to other aspects of the registered image. Additionally or alternatively, relative intensity of registered image components are varied using a software-based program that is operational by the operator and/or automatic. Optionally, a picture of the registered image shown on the viewing station is produced and placed, for example, on an image viewing apparatus in the operating theater. Additionally or alternatively, the image on the viewing station is projected by a projector onto a projection site, for example, located in the operating theater.  
           [0014]    In an embodiment of the present invention, a projector projects the registered image, including an optical image, and optionally a nuclear and/or X-ray image, onto the subject&#39;s corresponding anatomy. An operator manipulates the projection so that the optical image of the registered image lines up with the subject&#39;s skin anatomy. In an embodiment of the invention, the image is manipulated so that only the planned incision is visible and the surgeon makes an incision using the projected incision as a guide.  
           [0015]    In an embodiment of the invention, the registered image, whether a picture, a viewing station image and/or a projector image, is sectored into multiple component including landmarks that appear at different stages of the surgery. Landmarks include, for example, skin markings, a drawn incision and/or anatomic structures such as nerves, cartilage or vascular tissue. As the surgery progresses to different anatomical sectors or depths within the target, the surgeon uses the component images as a visual map of anatomic structures, landmarks and/or other features to be encountered.  
           [0016]    There is thus provided an apparatus for providing image registration of a target, comprising a gamma camera that acquires a nuclear image of said target, an optical imager in a fixed or known relationship with respect to said gamma camera that acquires an optical image of said target and an image registrator operative to receive and register said nuclear image and said optical image.  
           [0017]    In an exemplary embodiment, said gamma camera and said optical imager are mounted on a gantry. Optionally, the optical imager comprises a digital camera or a video camera.  
           [0018]    In an exemplary embodiment, said registrator receives images of said target from an X-ray imager and registers an X-ray image with said optical image. Optionally, said X-ray imager is fixed or moveable in a measurable relationship with respect to said gamma camera. Alternatively or additionally, said X-ray imager is mounted on a gantry together with said nuclear camera and gamma camera and said optical imager.  
           [0019]    In an exemplary embodiment, the X-ray imager provides a planer X-ray image. Alternatively or additionally the X-ray imager provides a planer digital X-ray image and/or a tomographic image.  
           [0020]    In an exemplary embodiment, the optical imager images optically visible markers on said target, wherein said image register an image generated by said nuclear imager with an optical image including said optical markers. Optionally the optical imager includes an X-ray imager that registers an image received by said X-ray imager with an optical image including said optical markers.  
           [0021]    In an exemplary embodiment, said apparatus comprises a display that displays a registered image. Optionally, said display comprises an image highlighter control operative to change the relative emphasis of said nuclear image and said optical image in said registered image, responsive to an operator input.  
           [0022]    In an exemplary embodiment, the image highlighter is provided on said data display that changes the relative emphasis of one or more of said X-ray image, nuclear image and optical image in said registered image. In a further exemplary embodiment, said apparatus includes an X-ray imager, wherein a tissue emphasizor is provided on said display that changes the relative emphasis of one or more tissues in said registered image.  
           [0023]    Optionally, said emphasizor includes an image demarcator control operative to provide demarcation of an incision on said registered image. Optionally, said demarcator includes a demarcator emphasizor that changes the relative emphasis of said incision demarcation on said registered image.  
           [0024]    In an exemplary embodiment, a radioactive component expressor is included in said data display that changes the relative emphasis of one or more of said tumor and tumor nodes in said registered image. Optionally, said radioactive component expressor changes the relative emphasis of one or more of said radioactive markers, tumor and tumor nodes in said registered image.  
           [0025]    In an exemplary embodiment, the image registrator provides one or more printed registered images. Alternatively or additionally, the image registrator includes a plurality of registered image viewing stations. Optionally, the apparatus includes a data storage device, wherein the registered image is saved on retrievable storage media.  
           [0026]    There is thus provides a method for registering nuclear and optical images of a target, comprising obtaining a nuclear image of a target, obtaining an optical image of a target and registering said nuclear image and said optical image. Optionally, said method includes obtaining an X-ray image of said target and registering it with said nuclear image and said optical image.  
           [0027]    In an exemplary embodiment, optical markers are placed on said target and recording said target with said optical imager. Optionally, said optical markers that are radioactive on said target and recording said target with said nuclear imager.  
           [0028]    In a further exemplary embodiment, a planned tissue incision is marked on said registered image and said registered image is output on a viewing station image. Optionally a hard copy of said registered image is put out. Further, an incision on said target is marked using said registered image as an incision guide.  
           [0029]    There is thus provided a method for image registration, comprising providing a composite image of the internal and external structure of a portion of a subject, adjusting the relative intensities of the internal and external components of the image and displaying the composite image. In an exemplary embodiment, the external image comprises an optical image. In an exemplary embodiment, the internal image comprises a gamma camera image. Optionally, said displaying includes displaying on a monitor. Optionally said displaying includes providing a hard copy. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0030]    Exemplary non-limiting embodiments of the invention will be described with reference to the following description of embodiments in conjunction with the figures. Identical structures, elements or parts which appear in more than one figure are preferably labeled with a same or similar number in all the figures in which they appear.  
         [0031]    [0031]FIG. 1 is a representation of a radiographic and nuclear image registration system, according to an embodiment of the present invention;  
         [0032]    [0032]FIG. 2 is a representation of a projected registered image, according to an embodiment of the present invention;  
         [0033]    [0033]FIG. 3 is a representation of a gantry for obtaining radiographic and nuclear images registered with an X-ray image, according to an embodiment of the present invention;  
         [0034]    [0034]FIG. 4 is a representation of optical and nuclear images registered with an X-ray image, according to an embodiment of the present invention; and  
         [0035]    [0035]FIG. 5 is a representation of a registered image that has been sectored into component images, according to an embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION OF EMBODIMENTS  
       [0036]    [0036]FIG. 1 is a representation of a nuclear image  120 , including a tumor  112  and nodes  240  that have absorbed a nuclear medicine agent, and an optical skin image  110  of a target  430  on a subject  438 . Nuclear image  120  and optical skin image  110  are registered to provide a registered image  230  that includes an image of tumor  112  and nodes  240  and surface features of skin image  110 . By utilizing guideposts from optical skin image  110  in respect to image of tumor  112  and nodes  240 , the surgeon draws an incision tracing image on registered image  230  corresponding to the planned physical incision.  
         [0037]    In an exemplary embodiment, guideposts that aid in locating incision tracing image  310  consist of skin anatomy, for example a bone protrusion  258 . Additionally or alternatively, landmarks comprise, for example, hair, birthmarks, scars, surface contours and/or tattoos.  
         [0038]    In an embodiment of the present invention, skin markers  464  are placed on target  430  to provide skin marker images  264  in optical skin image  110  that appear in registered image  230 . The surgeon makes an incision  190  in relation to skin markings  464  by viewing skin marking images  264  on registered image  230 . To accommodate a possible long delay between placement of skin markers  464  and the onset of surgery, skin markers  464  may be indelible, for example, for about 12 hours.  
         [0039]    Optionally, skin markers  464  comprise a radiopaque paint that, for example, appears in nuclear image  120  as markers  264  and in optical skin image  110  as skin markers  264 ′. In an embodiment of the invention, an operator superimposes a picture of optical image  120  with skin markers  264 ′ on a picture of nuclear image  120  with markers  264  to provide registered image  230  with skin marking images  264 ′.  
         [0040]    In an embodiment of the present invention, an image registrator  450  (FIG. 3) registers images  110  and  120  to provide a single picture  488  that is, for example a hard copy, of registered image  230 . To provide registered image  230 , for example, image registrator  450  aligns markers  264  in received nuclear image  120  with skin markers  264 ′ in received optical skin image  110 . Additionally or alternatively, the fields of view of a gamma camera  422  and an optical imager  420  are precisely aligned, for example on a gantry  400 , and received nuclear image  120  and optical skin image  110  are automatically registered by image registrator  450 .  
         [0041]    Picture  488  includes landmarks and/or skin markers  264 ′, corresponding to skin markings  464  that appear on target  430  and is, for example, placed on an image viewer  392  (FIG. 3) in the surgical theater. Prior to, or as surgery begins, the surgeon makes incision tracing image  310  on picture  488  that most efficiently encompasses tumor  112  and nodes  240  and uses it as a map for making incision  190 .  
         [0042]    Additionally or alternatively, registered image  230  is provided on a viewing station  452 , or projected as an image from a projector  478  (FIG. 2) within the surgical theater that is viewed by the surgeon and used as a map by which the surgeon cuts skin incision  190  on target  430 .  
         [0043]    Optionally, prior to donning sterile surgical garb, the surgeon manipulates controls  482  to produce incision tracing image  310  on viewing station  452 . Optionally, viewing station  452  provides picture  488  and/or image from projector  478  that includes incision tracing  310 .  
         [0044]    The surgeon duplicates incision tracing image  310  on subject  438  as incision  190 , using the location of skin marker images  264  and/or anatomic landmarks as guideposts. Optionally, viewing station  452  is programmable so an operator can program it to show multiple images, each image including, for example, incision tracing  310 , along with one or more anatomic landmarks, for example, nerves, cartilage, tumor or vascular tissue, as will be explained below. These images provide the surgeon with maps of the target  430  as he cuts incision  190  deeper to different levels of tissue.  
         [0045]    [0045]FIG. 2 is a representation of projector  478  that projects registered image  230 , comprising registered images  110  and  120  onto a viewing area, for example target  430 . Orientation controls  476  are used to change the position, orientation and/or size of projected registered image  230  so that skin marker images  264  properly align with skin markings  464  and registered image  230  is properly aligned with target  430 .  
         [0046]    Registered image  230 , for example, is shown on screen  452  and controls  482 , for example, are used to draw incision tracing image  310  on screen  452  so that it appears on projected registered image  230 . Registered image  230 , including incision tracing image  310 , is projected onto target  430  and manipulated, for example with orientation and size controls  476  to line up with target  430 . At the onset of surgery, the surgeon cuts physical incision  190  directly into the patient skin, following projected incision tracing image  310 . Additionally or alternatively, the surgeon draws a guide on the patient skin following projected incision tracing image  310 , turns off projected image  230  and makes incision  190  along the guide.  
         [0047]    In an embodiment of the present invention, a non-sterile assistant operates orientation controls  476  to change position, orientation and/or size of projected registered image  230 . Additionally or alternatively, sterile covers on controls  476  allow the surgeon to manipulate controls  476  while in the sterile operating theater. Optionally, controls  476  are operated by surgeon voice activation in the operating theater. Additionally or alternatively, controls  476  are non-sterile foot pedals accessible by the surgeon in the operating theater.  
         [0048]    In an embodiment of the invention, registered image  230  is aligned on target  430  and then skin image  110  is de-emphasized in projected registered image  230 , leaving nuclear image  120  projection and/or skin markers image  264 ′ projected on target  430 . The surgeon physically makes incision  190  directly on target  430  to encompass tumor  112  and nodes  240 .  
         [0049]    Additionally or alternatively, skin image  110  is emphasized in registered image  230  and projected with skin markers  264 ′ and the surgeon makes incision  190  on target  430  according to skin markers  264 ′. Additionally or alternatively, components of registered image  230 , for example anatomic structures, are emphasized or de-emphasized as will be explained below.  
         [0050]    In an embodiment of the present invention, a laparoscopic probe  352  with a control panel  354  is used to take, for example, a biopsy from target  430 . Using skin marker images  264  on viewing station image  356  and skin markings  464  on patient target  430 , the surgeon can accurately position probe  352  to take a biopsy.  
         [0051]    [0051]FIG. 4 is a representation of optical image  110  and nuclear image  120  registered with an X-ray image  444  to provide a registered image  410  on viewing screen  452 . Optionally, image  410  can be manipulated with controls  482  to demonstrate individual images  110 ,  120  and/or  444  and/or multiple images that are overlaid in any combination as required by the surgeon.  
         [0052]    Emphasizing different images,  110 ,  120  and/or  444  of registered image  410  allows the surgeon, for example, to accurately estimate the tissue planes in which tumor  112  and/or individual nodes  240  are located. For example, one or more sentinel nodes  240  may be on a plane below a specific organ, such as a spine  462  on X-ray image  444 . By emphasizing bony spine image  462  in registered image  410 , while de-emphasizing optical image  110  and/or nuclear image  120 , the surgeon clarifies the location of sentinel nodes  240 . Considering this knowledge, he revises his initial incision tracing image  310 , for example, to be two small incisions on either side of spine  462 , rather than a single incision encompassing spine  462 .  
         [0053]    In an embodiment of the invention, as shown in FIG. 5, image registrator  450 , produces registered image  410  on viewing screen  452  and the operator uses controls  482  to highlight specific anatomic structures and/or regions, for example, a nerve N, an area of cartilage C vascular tissue V and/or tissue that has absorbed a nuclear medicine agent, for example, tumor  112 . The operator, for example, may produce an image  510  with emphasized incision  310  and nerve N and de-emphasized optical image  110 . Additionally or alternatively, image  510  is produced using a software-based program that is operational by the operator and/or an automatic program. Using image  510  at the outset of surgery, the surgeon for example, avoids over-extending incision  310  and possibly severing nerve N.  
         [0054]    Additionally or alternatively, the operator may produce an image  520  with emphasized incision  310 , cartilage area C and tumor  112 . The surgeon, for example, may call for display of image  520  to provide an accurate map of structures as he deepens incision  310  into cartilage area C.  
         [0055]    Additionally or alternatively, the operator may produce an image  544  with emphasized spine  462  and tumor nodes  240  that have absorbed a nuclear medicine agent. The surgeon, for example, may call for display of image  544  as he begins deep dissection of nodes  240 .  
         [0056]    Images  510 ,  520  and/or  544 , for example, are displayed, for example, according to the surgeon&#39;s wishes throughout the surgical procedure, as pictures  488  on a picture viewing apparatus, as images on viewing station  452  and/or as projections from image projector  420 . Additionally or alternatively, images  510 ,  520 ,  544  or other images composed from registered image  410 , are shown on multiple viewing stations  456 , located for example throughout a hospital, that can be viewed by qualified professionals. This provides an opportunity, for example, for multi-disciplinary participation in planning and/or observation of surgery of target  430 .  
         [0057]    [0057]FIG. 3 is a representation of gantry  400  comprising gamma camera  422  and optical imager  420 . Optionally, gantry  400  includes X-ray imager  412 . Gantry  400 , for example, moves in direction  434  until a field of view  432  of subject  438  can be taken of target  430 . For further details of gantry  400 , please refer to Balan, et al., WO 00/75691 A1.  
         [0058]    In an embodiment of the invention, gantry  400  takes images with gamma camera  422 , optical imager  420  and optionally X-ray imager  412  and sends these images to image registrator  450 . Image registrator  450  registers the images to produce picture  488 , an image for projector  478  and/or an image on viewing station  452 . Optionally, output  452  is connected to a storage device  454  that records registered image  230  on appropriate storage media that can be retrieved to be viewed on multiple viewers  456 , for example, located in different hospital areas and/or departments, allowing intra-disciplinary consultation over registered image  230 .  
         [0059]    In an embodiment of the present invention, X-ray imager  412  comprises a planer X-ray imager. Additionally or alternatively, X-ray imager  412  comprises a planer X-ray imager that provides digital planer X-ray images. Additionally or alternatively, X-ray imager  412  comprises an X-ray tomograph.  
         [0060]    In an exemplary embodiment, gamma camera  422  registers an image of a radioactive nuclear medicine agent, for example Gallium-67 citrate or any other appropriate radioactive nuclear medicine agent, that has concentrated in, for example, tumor  112  and nodes  240 .  
         [0061]    Optical imager  420  is, for example, a digital camera that provides digital images that are, for example, registered in registered image  230 . Additionally or alternatively, camera  420  is a video camera that provides video images that are registered in registered image  230 . Additionally or alternatively, camera  420  is held separately from gantry  400  and is moveable with respect to gantry  400  in a measurable relationship to gantry  400 .  
         [0062]    The present invention has been described using non-limiting detailed descriptions of embodiments thereof that are provided by way of example and are not intended to limit the scope of the invention. It should be understood that features and/or steps described with respect to one embodiment may be used with other embodiments and that not all embodiments of the invention have all of the features and/or steps shown in a particular figure or described with respect to one of the embodiments. Variations of embodiments described will occur to persons of the art.  
         [0063]    Furthermore, the terms “comprise,” “include,” “have” and their conjugates, shall mean, when used in the claims, “including but not necessarily limited to.” 
         [0064]    It is noted that some of the above described embodiments may describe the best mode contemplated by the inventors and therefore may include structure, acts or details of structures and acts that may not be essential to the invention and which are described as examples. Structure and acts described herein are replaceable by equivalents which perform the same function, even if the structure or acts are different, as known in the art. Therefore, the scope of the invention is limited only by the elements and limitations as used in the claims.