1. Field of the Invention
The present teaching relates to method and system for medical image processing and methods and systems incorporating the present teaching. More specifically, the present teaching relates to method and system for interactive medical image processing and methods and systems incorporating the present teaching.
2. Description of Related Art
With the advancements made in the field of medical imaging, minimally invasive techniques for the ablation of liver tumors have been made possible. Among such minimal invasive techniques, percutaneous thermal ablation has been studied in different forms. Currently, percutaneous radiofrequency ablation is one of the most promising alternatives to open surgery for the treatment of liver cancer. This operation is a minimally invasive procedure in which a needle is inserted into targeted tissues that are destroyed by heat. This modality has been introduced for treating patients who have non-resectable hepatic metastases. The success of such an operation depends largely on the accuracy of the needle insertion because when it is accurate, it is possible to destroy the whole tumor without damaging nearby organs so as to minimize the risks of a local recurrence. To ensure accuracy, a preoperative treatment planning is usually performed, which is one of the crucial factors in avoiding complications or even deaths.
Conventionally, a radiologist who performs a preoperative treatment planning relies on images of 2D scanned slices to determine the positioning of the needles. Unfortunately, this makes the planning of such a treatment rather difficult when relying only on 2D scanner slices. Therefore, there is a need for a solution which can be used to assist a medical personnel to perform a preoperative treatment planning in a more reliable and accurate manner.
The inventions claimed and/or described herein are further described in terms of exemplary embodiments. These exemplary embodiments are described in detail with reference to the drawings. These embodiments are non-limiting exemplary embodiments, in which like reference numerals represent similar structures throughout the several views of the drawings, and wherein:
a) depicts a three dimensional (3D) volume having 3D objects contained therein;
b) shows a 3D volume containing 3D objects displayed in a 3D coordinate system;
c) shows a 3D volume displayed in a 3D coordinate system in an opaque mode;
a) depicts a 3D scene having 3D objects displayed therein and 3D point specified in the 3D scene for placing a virtual probe, according to an embodiment of the present teaching;
b) depicts a 3D scene with a plurality of 3D objects displayed therein and a movable and adjustable probe being placed at a specified 3D point near an object, according to an embodiment of the present teaching;
a)-4(c) show different variations associated with movable and adjustable features of a virtual probe, according to an embodiments of the present teaching;
a) illustrates the concept of detecting an obstacle encountered by a probe, according to an embodiment of the present teaching;
b) depicts an exemplary means to generate a warning of a detected obstacle, according to an embodiment of the present teaching;
The present teaching pertains to method and system for facilitating interactive placement of a needle or a probe at a target location inside a three-dimensional (3D) volume (object), possibly together with nearby supporting anatomies, rendered in a 3D space on a computer screen. The disclosed method and system may be applied in pre-surgical planning for percutaneous procedures such as radiofrequency ablation to assist medical personnel to better prepare for an accurate needle entry point or a proceeding path to enable the medical personnel to observe any potential possible complication or difficulties associated with the entry point or along the path. Three-dimensional image reconstruction allows a more intuitive 3D visualization of a patient's anatomy and makes the preoperative treatment planning more realistic and more accurate. Different facilitating means is also described for enhanced visualization of spatial relationships between organs, probes, and surrounding anatomies.
In some embodiment, the 3D volume 100 may be sliced into a plurality of 2D slices along some 3D orientation so that each of the slice provides 2D imagery of the 3D volume 100 along a certain direction. To facilitate effective 3D visualization, these 2D slices can be placed inside this 3D scene to enable a viewer to observe the composition of different objects, if any, on a planar surface. Through this means, one may be able to observe the spatial relationship among different segmented 3D objects. The concept is described in U.S. Pat. No. 7,315,304, entitled “Multiple Volume Exploration System and Method”.
A user may manipulate the visualization of the 3D volume 100 in different ways. For example, the entire 3D volume may be rotated and translated with respect to the 3D coordinate system 120. This may facilitate the user to observe the spatial relationships among different objects from different angles. In addition, the visualization of each segmented object can be independently manipulated, e.g., a 3D object may be made visible or invisible so that a user can see the areas of the 3D volume 100 where it is occluded by the selected 3D object. This may be done by adjusting the transparency of such selected 3D object. When the selected 3D object is made completely transparent or highly translucent, an object occluded by the selected 3D object can be made more visible. In some embodiments, a 3D object of interest can be made opaque and when additional 2D slices for that object are also rendered, one can be more clearly observe the internal structure of the 3D object. For example, when a 3D object corresponds to skin of a human body, when a user elects to visualize the skin in a transparent mode, all the objects inside of the skin structure can be made visible. On the other hand, if the user elects to visualizes the skin in an opaque mode, none of the 3D objects wrapped inside of the skin will not be visible. This is shown in
a) depicts a three dimensional scene 300 having three dimensional objects displayed therein and a 3D location specified, according to an embodiment of the present teaching. To perform a percutaneous pre-operational surgical planning, a user may interactively interface with a system developed in accordance with the present teaching to specify a 3D location at which a virtual probe is to be placed. This is shown in
b) shows that once the 3D coordinate corresponding to a 2D point selected on a display screen is determined, a virtual probe or needle 204 may be virtually placed at the 3D coordinate position in the 3D space 300. The virtual probe or needle 204 may have a straight shape or any other shape as needed, as shown in
The virtual probe, once inserted, may be adjusted. This may be done by allowing a user to use a tool (e.g., in a GUI, use a drag and pull motion) to move different parts of the virtual probe based on needs. For example, a user may be allowed to drag the tip 301 of the probe and pull to a desired 3D location. A user may also be allowed to grab the body 302 of the probe and drag it so that the tip of the probe remains the same. Similarly, a user may be allowed to drag the handle 303 of the tip and move around. In other embodiments, a user may be allowed to move the tip by dragging the body 302 or the handle 303.
When a virtual probe is created, it may have a certain length and such a length may be displayed along with the probe (see
A configuration using a probe of a fixed length may be helpful in terms of having a more realistic simulation in pre-surgical planning. When a probe is configured with a fixed length, the movement of the probe may be accordingly determined. For instance, e.g., the movement of the probe may be confined to skin 102, or to a half sphere with respect to the tip of the probe when the length of the probe is fixed. This is shown in
In some embodiments, the length of a probe may be made dynamic. A user can use a probe with a dynamic length as shown in
In some embodiments, more than one probes may be placed.
The system according to the present teaching may also provide the means to allow a user to view the anatomical structure of a 3D object along a probe that has been placed. In
When obstacles are defined, the system may provide automatic collision detection capabilities while a probe is placed into a 3D scene. In
In some embodiments, obstacles may be individually turned on or off so that a user can experiment and explore different scenarios when moving and inserting the probe.
Once obstacles or areas where a probe is prohibited to enter, it may also be possible to mark up such regions in the 3D scene as areas that the probe may not enter. For example, in some procedures, bones may be considered as obstacles. In addition, major arteries may likely be considered as areas that are constrained or prohibited regions. According to the present teaching, means may be provided to automatically identify these constrained regions and mark as such on the skin surface corresponding to such prohibited areas. This is illustrated in
Such a user input may be dispatched to relative action modules according to the nature of the input or some preset system configurations. When the system receives an input, the input is interpreted at 1020. There may be different types of input. One exemplary type of input relates to definitions such as definitions of a target object, an obstacle, or a prohibited region in a 3D volume. Another exemplary type of input is an instruction related to insertion, manipulation, and visualization of different 3D objects in the process of a percutaneous pre-surgical planning.
Regarding defining different types of objects, depending on the nature of a particular procedure, a different target object may be defined. For instance, for a procedure to treat liver tumor, a lesion in a liver may identified as a target object. For each procedure, different types of obstacle may also be defined. An obstacle may be defined to be an object that a probe can not penetrate. One example of such an obstacle may be bones. However, if a different procedure requires a probe to enter into a bone structure, bones may be defined as target rather than obstacle. Another exemplary type of object is a prohibited region, which may be defined as a region that if a probe's entry may cause harm. For instance, a user may select one or more major arteries around a liver as prohibited regions to enter a probe. In this example, to allow a probe to enter into a lesion inside a liver, the probe has to take a route that avoids the bones and major arteries.
Selections of target object, obstacles, or prohibited regions may be made based on a plurality of choices, which may correspond to all the segmented 3D objects. For instance, the segmented objects in a 3D volume representing a human body may include skin, liver, pancreas, kidney, lesions inside or nearby certain organs, surrounding tissue, bones, blood vessels, etc. Depending on the procedure to be performed, a lesion associated with, e.g., the liver may be selected as a target object. Depending on the specific treatment to be performed, different obstacles or prohibited regions may be selected. For instance, for percutaneous treatment, bones may be selected as obstacles and major blood vessels may be selected as prohibited regions. Once such selections are interpreted, the system sends such definitions to a collision detection operation at 1055, which utilizes such information in automatically detecting when a probe encounters or enters into such objects.
As discussed, another type of input correspond to instructions related to insertion, manipulation, and visualization of different 3D objects. Different types of instructions may be further recognized. If the input instruction relates to insertion of a virtual probe, determined at 1025, the system further receives, at 1030, a 2D coordinate corresponding to a screen location specified by a user as where a probe is to reach. To translate the 2D screen location to a 3D coordinate at which a probe is to reach, a transformation between the 2D coordinate and a 3D coordinate is performed at 1035. Since a received 2D coordinate may correspond to either a user's desire to insert a new probe or to make an adjustment to an already inserted probe, it is further determined, at 1040, whether the operation requested corresponds to creation of new probe or adjusting an existing probe.
If the user's request is to insert a new probe, the system renders, at 1045, a new probe at the transformed 3D coordinate. The process then proceeds to detecting, at 1055, a potential collision between the probe and any other object that has been defined as either an obstacle or a prohibited region. If the user's request is to make an adjustment to an existing probe, the system adjusts, at 1050, the existing probe to the transformed 3D coordinate and then proceed to collision detection at 1055. When a collision is detected, the system may generate a warning message, at 1060, to caution the user that the probe may have encountered some obstacle or entered into a prohibited region. The manner the warning message is generated and presented may depend on the system setting. For example, the system may be defaulted to flash on the location where the collision is detected (see
When there are multiple existing probes, an additional step (not shown) may be performed, in which the user and the system may interactively determine which probe is to be adjusted. In addition, the 2D coordinate received from the user may correspond to a manipulation with respect to the tip, the body, or the handle of a probe, depending on, e.g., what is the closest part and which mode of operation the system is placed under (not shown). For example, if the system is set in a mode in which a probe is to be manipulated using the handle of the probe, then the 3D coordinate transformed from the 2D coordinate received from the user is where the handle of the probe is to be re-located. If the probe is selected to have a fixed length, then the 3D coordinate needs also to be determined based on the fact that the handle of the probe has to be on a sphere centered around the tip of the probe. A user can also switch between different modes of operation. For instance, a user may elect first to adjust the probe's tip to a best location by manipulating with respect to the tip of the probe. Once the tip location satisfies the needs of a procedure, the user may then switch to a mode in which the manipulation of the probe is through the handle of the probe. Through such manipulation via the handle of the probe, the user may adjust the entry point of the probe on the skin, without affecting the tip position, to avoid any obstacle or prohibited regions.
If the input instruction relates to 3D scene manipulation, determined at 1025, the system proceeds to 1065 to handle 3D scene manipulation. 3D scene manipulation may include object oriented scene rotation, zooming, visualization mode, etc. In some embodiments, when a 3D scene is moved around, a probe that has been inserted into the 3D scene may be moved around accordingly. In this way, a user may be able to observe the spatial relationship between the probe and surrounding objects from different angles. In some embodiments, through 3D manipulation, a user may manipulate the visibility of individual object by, e.g., making them transparent, opaque, or translucent. In some situation, a user may also control to view a 2D cross sectional view of an object along the probe and may arbitrarily change the location at which a 2D cross sectional view is generated and displayed. In other embodiment, a user may also be able to manipulate the 3D scene via the probe by, e.g., dragging the handle of the probe to rotate the entire 3D scene.
In some embodiments, it can also set that manipulation to a 3D scene does not affect the 3D pose of the probe. This may be useful at times because the user can adjust the 3D volume, e.g., so that or until a collision is avoided. In this case, whenever the 3D scene is changed (e.g., rotated or translated), the system automatically proceeds to 1055 to detect collisions and subsequently report a collision at 1060 if it is detected.
If the input instruction relates to operational control, determined at 1025, the system proceeds to 1070 to perform instructed control. There may be different types of operational controls.
A user 1205 may interact with the system 1200 via a user interface displayed on the display device 1210. The GUI controller 1215 may control interaction between the system 1200 and user 1205. If the user 1205 desires to use a tool associated with a virtual probe once a 3D scene is set up, the user may request the system to retrieve 3D object information from the 3D object management 1260 and render such objects via the 3D scene rendering mechanism 1255. When such user request is entered via the user interface, the GUI controller 1215 may then interpret the request and accordingly activates appropriate functional modules to perform the requested operations.
For example, if request is to change the orientation of the 3D scene, the system may activate the 3D scene manipulator module 1275 to modify the orientation of the 3D scene based on the specification from the user. During this process, the user and the GUI controller may continuously interact, e.g., user may click a point in the 3D scene and drag along a certain direction so that the entire 3D scene may move along in the same direction. Similarly, the user may exercise the same control with respect to a particular 3D object such as a virtual probe.
A user may also interact with the system to exercise various controls over a probe. When the user manually controls a probe via a 2D display screen, the 2D/3D transformation mechanism 1220 dynamically transforms a 2D screen point to a 3D point in the 3D scene, and then pass the 3D point to the probe handling module 1230 which determines whether it is a new probe creation operation or an adjustment operation to be made to an existing probe. The desired probe is then rendered in the 3D scene by the probe rendering mechanism 1250. In the process of moving an existing probe, the collision detection module 1235 is operative to detect intersection between the applicable probe and any 3D objects that have been defined as either an obstacle or prohibited regions. The collision detection module 1235 may also generate warning information when a collision is detected.
As discussed herein, the system also provides the means for a user to exercise various control regarding the operation of the system. For example, via the control panel facilitator 1225, a user may activate or deactivate a probe view controlled by the probe view manipulation module 1265. A user may also control other visualization parameters such as transparency through the probe view rendering mechanism 1240. A user may also set desired mode of display which may also be personalized and such a setting may be applied automatically when the user signs up with the system. For example, a user may desire to always have the skin (a 3D object) displayed in a transparent mode. Another user may desire to have a particular sound as a warning whenever a collision is detected. A user may also control the activation or deactivation of computation of a constraint zone by interacting with the constraint zone calculation module 1270 or control the display of a detected constraint zone by interacting with the constraint zone rendering mechanism 1245.
While the inventions have been described with reference to the certain illustrated embodiments, the words that have been used herein are words of description, rather than words of limitation. Changes may be made, within the purview of the appended claims, without departing from the scope and spirit of the invention in its aspects. Although the inventions have been described herein with reference to particular structures, acts, and materials, the invention is not to be limited to the particulars disclosed, but rather can be embodied in a wide variety of forms, some of which may be quite different from those of the disclosed embodiments, and extends to all equivalent structures, acts, and, materials, such as are within the scope of the appended claims.
The present invention claims priority of provisional patent application No. 60/989,580 filed Nov. 21, 2007, the contents of which are incorporated herein in their entirety.
Number | Date | Country | |
---|---|---|---|
60989580 | Nov 2007 | US |