CN1842297A - System and method for polyp visualization - Google Patents

Abstract

A system and method for determining a location and a direction for viewing a protrusion, comprising: casting a plurality of rays in an outward direction from a point, wherein the point is inside a protrusion (215); selecting at least one of the plurality of rays for determining a location and a direction for viewing the protrusion (220); and determining the location and the direction for viewing the protrusion using the selected at least one of the plurality of rays (225).

Description

Systems and methods for visualization of polyps

Cross References to Related Applications

This application claims the benefit of US Provisional Application No. 60/482,581, filed June 25, 2003, a copy of which is incorporated herein by reference.

Background of the invention

1. Technical field

The present invention relates to three-dimensional (3D) visualization of medical images, and more particularly to systems and methods for determining the position and orientation of observed protrusions, such as colon polyps, in medical images.

2. Discussion of related technologies

In the field of medical imaging, various systems have been developed for producing medical images of various anatomical structures of individuals for the purpose of screening and evaluating physical conditions. These imaging systems include, for example, computed tomography (CT) imaging, magnetic resonance imaging (MRI), positron emission tomography (PET), and the like. Each imaging modality may have unique advantages over the others for screening and evaluating certain types of diseases, medical conditions, or anatomical abnormalities including, for example, colonic polyps, aneurysms, pulmonary nodules, cardiac or Calcification of arterial tissue, cancerous microcalcifications or masses of breast tissue, and various other lesions or abnormalities.

For example, a CT imaging system may be used to obtain a set of cross-sectional images or two-dimensional (2D) "slices" of a region of interest (ROI) of a patient for the purpose of imaging organs and other anatomical tissues. This CT modality is commonly used for the purpose of diagnosing diseases because it provides precise images illustrating the size, shape and position of various anatomical structures such as organs, soft tissues, and bones, Evaluation of abnormal anatomy is more precise.

One method used by physicians, clinicians, radiologists, etc. to diagnose and evaluate physical conditions is to manually examine hard copies (X-ray films, prints, photographs, etc.) of medical images reconstructed from acquired datasets, to identify features of interest. For example, CT image data obtained during a CT examination can be used to generate a set of 2D medical images (X-ray film) that can be viewed by trained physicians, clinicians, radiologists, etc. To identify potential abnormal anatomy or injury. However, three-dimensional (3D) mapping of 2D data typically enables, for example, a trained radiologist to determine whether a suspected structure is indeed an abnormality.

Various image processing systems and tools have been developed to help physicians, clinicians, radiologists, etc. evaluate medical images to diagnose physical conditions. For example, computer-aided detection and/or diagnosis (CAD) tools have been developed for various clinical applications to provide automatic detection of physical conditions on medical images. In general, CAD systems use digital signal processing methods and/or techniques of image data (e.g., CT data) to automatically detect colonic polyps and other abnormal anatomical structures, such as pulmonary nodules, lesions, aneurysms, heart or artery Calcification of tissue, microcalcification or cell mass of breast tissue, etc. Additionally, inspection tools have been developed that allow users to select and annotate portions of image data. The CAD and inspection tools are used to generate locations within the image data that can be inspected using 2D and 3D drawing techniques.

One technology used in conjunction with conventional CAD tools is virtual colonoscopy. When performing a virtual colonoscopy, a functional model is used to explore a virtual space drawn from a three-dimensional (3D) image obtained by a scanner. One such model is a virtual camera, which can be used as a reference point for an observer and/or operator, eg a radiologist at a workstation, to explore the virtual space. Generally, the operator has two types of camera controls according to which the operator can move through the virtual space.

The first is full operator control of the camera, which allows the operator to manipulate the camera in different positions and orientations to achieve the desired viewing. In other words, the operator can direct the camera. This enables the operator to probe specific parts of interest while ignoring others. However, full control of the camera over a large virtual field is tedious and tiring, and the operator may not observe all important features, such as colon polyps, during his detection.

The second technique of camera control is the scheduled navigation method, which assigns the camera a predetermined route to follow, and which does not require operator intervention. In other words, the operator is engaged in "autopilot". This allows the operator to focus on the virtual space being viewed without worrying about bumping into the walls of the environment being inspected. However, this second technique does not give the operator enough time to fully investigate the region of interest observed along the route of travel.

Therefore, there is a need for a technique that can combine data output using CAD methods or data from manual inspection so that medical experts can walk through a virtual space and inspect detected or marked locations in a small amount of time.

Summary of the invention

The present invention overcomes the foregoing and other problems encountered with known teachings by providing a system and method for determining the location and direction of viewing bumps.

In one embodiment of the present invention, the method for determining the position and direction of the observation bump comprises: projecting a plurality of rays in an outward direction from a point, wherein the point is within the bump; selecting one of the plurality of rays at least one ray to determine the position and direction for observing the bump; and using the at least one ray selected from the plurality of rays to determine the position and direction for observing the bump. The plurality of rays are projected into one of a spherical and ellipsoidal shape. The bump is one of a nodule, lesion, polyp, precancerous growth, and cancerous growth.

The method further comprises: obtaining a medical image comprising the protrusion, wherein the medical image is imaged by computed tomography (CT), helical CT, x-ray, positron emission tomography, fluoroscopy, ultrasound, and magnetic resonance (MR) One of the techniques is obtained. The method also includes: detecting the bump using computer-aided bump detection techniques; storing the determined location and direction for viewing the bump; and observing the bump from the determined location and direction for viewing the bump The bump. The point is manually selected by the user. This point is the center point of the bump.

A ray that takes the shortest distance from the point to the surface of the bump is selected to determine the position and direction for observing the bump. A plurality of rays that stop at the voting surface of the bump is used to determine a ray of the plurality that traverses the shortest distance from the point to the bump surface. A stopping point of the plurality of rays is determined by the gradient of the image, wherein the stopping point is used to determine a ray of the plurality of rays that traverses the shortest distance from the point to the surface of the bump. A stopping point of the plurality of rays is also determined using an air threshold, wherein the stopping point is used to determine a ray of the plurality of rays that traverses the shortest distance from the point to the surface of the bump.

A set of rays from the plurality of rays that experience the shortest average distance from the point to the surface of the bump is selected to determine a location and direction for viewing the bump. An opposite direction of the selected at least one ray of the plurality of rays determines a direction for viewing the protuberance. A position for observing the detected bump is determined by selecting a point along an extension direction of at least one selected ray among the plurality of rays. The selected point is a point at a fixed distance from the bump surface, and the longest selected ray is extended in air to the fixed distance. The fixed distance is based on the estimated size of the bump.

When a surface point on the bump is determined by the selected ray and one of the set of rays, a second plurality of rays is projected from the surface point into the air region of the cavity. The second plurality of rays is projected into one of a spherical and ellipsoidal shape. The longest ray of the second plurality of rays is selected to determine a location and direction for viewing the bump, wherein the direction for viewing the bump is opposite to the direction of the selected longest ray. The position is determined using a point along the selected ray and one of the estimated dimensions of the bump.

In another embodiment of the present invention, a system for developing bumps in a medical image includes: a memory device for storing a program; a processor in communication with the memory device, the processor and the program operative to: Cast a plurality of rays in an outward direction from a point, wherein the point is within the bump; select at least one ray from the plurality of rays to determine a location for viewing the bump; and use the selected one of the plurality of rays at least one ray to determine the location for viewing the bump.

A ray of the plurality of rays that takes the shortest distance from the point to the surface of the bump is selected to determine a position for observing the bump. The set of rays that experience the shortest average distance from that point to the surface of the bump is chosen to determine the location for viewing the bump. The position for observing the bump is determined by selecting a point along the extension direction of at least one selected ray among the plurality of rays. The selected point is a point at a fixed distance from the bump surface, and the longest ray is extended in air to the fixed distance, wherein the fixed distance is based on the estimated size of the bump.

At least one of the plurality of rays is selected to determine a direction for viewing the bump. A ray of the plurality of rays that traverses the shortest distance from the point to the surface of the bump is selected to determine a direction for viewing the bump. The opposite direction of the selected at least one ray of the plurality of rays determines the direction for viewing the bump. The set of rays that experience the shortest average distance from that point to the surface of the bump is chosen to determine the direction for viewing the bump.

When a surface point on a bump is determined by a selected ray and one of a set of rays, a second plurality of rays is projected from the surface point into the air region of the cavity, wherein the most of the second plurality of rays is selected. The longest ray is used to determine the position and direction for viewing the bump, where the direction for viewing the bump is opposite to the direction of the longest ray selected. The position is determined using a point along the selected ray and one of the estimated dimensions of the bump.

In yet another embodiment of the present invention, a computer program product includes a computer usable medium having computer program logic recorded thereon to visualize bumps in a medical image, the computer program logic comprising: Program code for casting a plurality of rays into one of a spherical and ellipsoidal pattern, where the point is within a bump; for selecting at least one ray from the plurality of rays to determine a direction for viewing the bump program code; and program code for determining a direction for viewing the bump using at least one selected ray of the plurality of rays.

A ray of the plurality of rays that traverses the shortest distance from the point to the surface of the bump is selected to determine a direction for viewing the bump. The set of rays that experience the shortest average distance from that point to the surface of the bump is chosen to determine the direction for viewing the bump.

An opposite direction of at least one selected ray of the plurality of rays determines a direction for viewing the bump. At least one ray of the plurality of rays is selected to determine a location for viewing the bump. A ray of the plurality of rays that takes the shortest distance from the point to the surface of the bump is selected to determine a position for observing the bump.

The set of rays that experience the shortest average distance from that point to the surface of the bump is chosen to determine the location for viewing the bump. The position for observing the bump is determined by selecting a point along the extension direction of at least one selected ray among the plurality of rays. The selected point is a point at a fixed distance from the bump surface, and the longest ray is extended in air to the fixed distance, wherein the fixed distance is based on the estimated size of the bump.

When a surface point on a bump is determined by a selected ray and one of a set of rays, a second plurality of rays is projected from the surface point into the air region of the cavity, wherein the most of the second plurality of rays is selected. The longest ray is used to determine the position and direction for viewing the bump, where the direction for viewing the bump is opposite to the direction of the longest ray selected. The position is determined using a point along the selected ray and one of the estimated dimensions of the bump.

In another embodiment of the invention, a system for determining the position and direction of viewing a bump comprises: means for projecting a plurality of rays in an outward direction from a point, wherein the point is within the bump; means for selecting at least one ray from the plurality of rays to determine the position and direction for viewing the bump; and for determining the position and direction for viewing the bump using at least one of the rays selected from the plurality of rays installation.

In yet another embodiment of the present invention, the method for determining the position and orientation of a polyp observed in an image of the colon comprises: obtaining an image of the colon, wherein the image is computed tomography (CT), spiral CT, x-ray , positron emission tomography, fluoroscopy, ultrasound, and magnetic resonance (MR) imaging techniques; use computer-aided polyp detection techniques to detect polyps; project multiple rays from a point within the polyp, where the multiple The rays are projected into one of spherical and ellipsoidal patterns; the ray that experiences the shortest distance from the point to the surface of the polyp is selected, wherein one of the multiple rays that experiences the shortest distance from the point to the surface of the polyp is selected to determine the The position and direction for observing the polyp; use the selected ray to determine the position and direction for observing the polyp, wherein the opposite direction of the selected ray determines the direction for observing the polyp, and the position for observing the polyp Determined by selecting a point along the direction of extension of the selected ray, wherein the selected point is a point at a fixed distance from the surface of the polyp; and when performing virtual navigation of the colon, according to the determined position and orientation to observe the polyp.

The foregoing features are representative embodiments and are presented to facilitate understanding of the invention. It should be understood that these characteristics are not intended to be considered as limitations on the invention as defined by the claims, or as limitations on the equivalents of the claims. Accordingly, this summary of features should not be considered a determining factor in determining equivalents. Additional features of the invention will become apparent in the following description, from the drawings and from the claims.

Brief description of the drawings

1 is a block diagram of a system for determining the location and direction of a viewing bump according to an exemplary embodiment of the present invention;

FIG. 2 is a flow chart illustrating a method for determining the position and direction of an observation bump according to an exemplary embodiment of the present invention;

FIG. 3 shows the position and direction determined for viewing a bump, according to an exemplary embodiment of the present invention;

4A is another illustration of determining the position and direction for viewing a bump, according to an exemplary embodiment of the present invention;

4B is yet another illustration of determining the position and direction for viewing a bump, according to an exemplary embodiment of the present invention;

Figure 5 shows marked polyps in the colon "flying-around"; and

Figure 6 "flying-through" shows a colon according to an exemplary embodiment of the present invention.

Detailed Description of Exemplary Embodiments

FIG. 1 is a block diagram of a system 100 for determining the location and direction of a viewing bump, according to an exemplary embodiment of the present invention. As shown in FIG. 1 , the system 100 includes, among other things, a scanning device 105 , a personal computer (PC) 110 , and an operator console and/or virtual navigation terminal 115 connected via an Ethernet network 120 , for example. The scanning device 105 may be a magnetic resonance imaging (MRI) device, a computed tomography (CT) imaging device, a helical CT device, a positron emission tomography (PET) device, a two-dimensional (2D) or three-dimensional (3D) fluoroscopy imaging device, 2D, 3D or four-dimensional (4D) ultrasound imaging equipment, or x-ray equipment, etc.

PC 110 , which may be a portable or laptop computer, a personal digital assistant (PDA), etc., includes a central processing unit (CPU) 125 connected to an input 150 and an output 155 and a memory 130 . The CPU 125 includes a visualization module 145 that includes one or more methods for determining the location and orientation of the observed bumps in the medical image. The CPU 125 may also include a detection module, which is a computer-aided detection (CAD) module for detecting protrusions such as polyps in medical images, and a diagnosis module, which is used to perform automatic diagnosis or evaluation of medical image data Function.

Memory 130 includes random access memory (RAM) 135 and read only memory (ROM) 140 . Storage 130 may also include databases, disk drives, tape drives, etc., or combinations thereof. The RAM 135 functions as a data memory which stores data used during execution of programs in the CPU 125 and is used as a work area. ROM 140 functions as a program memory for storing programs executed in CPU 125 . Input 150 consists of a keyboard, mouse, etc., while output 155 consists of a liquid crystal display (LCD), a cathode ray tube (CRT) display, a printer, and the like.

The operation of the system 100 is controlled by a virtual navigation terminal 115 comprising a controller 165, such as a keyboard, and a display 160, such as a CRT display. The virtual navigation terminal 115 communicates with the PC 110 and the scanning device 105 so that the 2D image data collected by the scanning device 105 can be rendered as 3D data by the PC 110 and observed on the display 160 . It should be understood that the PC 110 may be configured to manipulate and display information provided by the scanning device 105 without the virtual navigation terminal 115, for example using the input 150 and output 155 devices used to run the 165 and certain tasks performed by display 160.

Virtual navigation terminal 115 further includes any suitable image rendering system/tool/application capable of processing the digital image data of the obtained image dataset (or portions thereof) to generate and display 2D and/or 3D images on display 160 . More precisely, the image rendering system may be an application program that provides 2D/3D rendering and visualization of medical image data and that runs on a general-purpose or special-purpose computer workstation. Additionally, the image rendering system enables the user to slice through a 3D image or multiple 2D images. PC 110 may also include an image rendering system/tool/application for processing the digital image data of the acquired image dataset to generate and display 2D and/or 3D images.

As shown in FIG. 1 , the development module 145 is also used by the PC 110 to receive and process digital medical image data, such as volumetric image data or multi-planar reformatted or such, as described above. raw image data, 2D reconstruction data (eg, axial slices), or 3D reconstruction data in any combination of formats. The data processing results can be output from the PC 110 to the image rendering system in the virtual navigation terminal 115 via the network 120 for generating 2D and/or 3D drawings of the image data according to the data processing results, such as organs or anatomical structures segmentation, color or brightness changes, etc.

It should be understood that the CAD system and method for determining the location and orientation of observed bumps in medical images according to the present invention may be implemented as an extension or alternative to traditional CAD methods, such as manual selection or for processing image data Other automatic development and detection methods. In addition, it should be understood that the exemplary systems and methods described herein can be readily implemented using 3D medical imaging and CAD systems or applications that are suitable for a wide variety of imaging modalities (e.g., CT, MRI etc.) and suitable for diagnosis and evaluation of various abnormal anatomical structures or injuries, such as colonic polyps, aneurysms, pulmonary nodules, etc. In this regard, although exemplary embodiments are described herein with reference to particular imaging modalities or particular anatomical features, this should not be considered limiting of the scope of the invention.

It should also be understood that the invention can be implemented in various forms of hardware, software, firmware, special purpose processors, or combinations thereof. In one embodiment, the invention is implemented in software, such as an application program tangibly embodied on a program storage device (e.g., floppy disk, RAM, CD ROM, DVD, ROM, and flash memory). The application program can be loaded onto and run by a machine comprising any suitable structure.

FIG. 2 is a flowchart illustrating the operation of a method for determining a position and direction of an observed bump in a medical image according to an exemplary embodiment of the present invention. As shown in Figure 2, 3D data is obtained from a medical image of a protuberance, which in this example is the colon (step 205). This is achieved by scanning the colon using a scanning device 105 , such as a CT scanner, operating at the virtual navigation terminal 115 to generate a series of 2D images related to the colon. These 2D images of the colon can then be transformed or converted into 3D rendered images. It should be understood that the medical image may be a cavity, and may be any one of pancreas, bronchus, larynx, trachea, sinus, ear canal, blood vessel, urethra, bladder, etc. in addition to the colon. The medical image may also be of non-tubular structures such as lung parenchyma or liver.

After obtaining 3D data from the colon, the 3D data of the colon is processed to detect polyps (step 210). More precisely, polyps were detected using conventional (CAD) techniques. It should be understood that various conventional CAD techniques may be used in accordance with the present invention. Furthermore, during step 210 the medical professional may manually select polyps from the medical image, for example by using a mouse or a computer input device such as input 150 to select a portion of the medical image.

As further shown in FIG. 2, after the polyp-related data has been received, rays are cast from a point (eg, a center point) in each polyp (step 215). These points may be provided to the operator of the virtual navigation terminal 115 upon request of such data by the operator. The operator can also manually select the point within the polyp by marking, eg, the center of the 2D image of the polyp, to view a 3D endoscopic map of the polyp, as discussed above in step 210 . These rays are then projected into spherical patterns and/or shapes using ray casting techniques. These rays can be projected into an ellipsoidal pattern, for example when the data is anisotropic. An example of multiple rays projected from a central point in a polyp is shown in Figure 3 and will be discussed in more detail below.

Each ray projected from the center point of one or more polyps is defined as a point and a direction. These rays pass through solid matter, such as tissue, but stop in air. As shown in Figure 3, the rays start at the center point and continue in a given direction until the rays encounter air. An exemplary ray can be defined mathematically as P+t*V, where P=(a,b,c) is a point and V=(x,y,z) is a vector defining a direction. Try different directions by systematically increasing the elevation and azimuth angles to cover all possible directions. The length is defined as the maximum value of t so that the vector remains inside the polyp and does not come into contact with the air.

After a ray has been cast from a point in each polyp, the ray that traverses the shortest distance from that point to the surface of the polyp is selected (step 220). Each ray is projected and/or extended eg from this point until it intersects the surface of the colon. The distance from this point to the surface of the colon is the stop distance. Therefore, the ray with the shortest length is the one with the shortest stopping distance. Alternatively, the group of rays with the shortest average length may be selected in step 220, for example, by averaging the stop distances of groups of N rays, where N is a predetermined number. After averaging, the group with the shortest average or average stopping distance is selected.

Determining the distance from a point in the polyp to the surface of the polyp can be defined using various methods. In one approach, the gradient difference may be used to determine a stopping point and thus be used to determine which ray or group of rays to select in step 220 . This is done using standard methods of computing image gradients. Sharp edges, which tend to have high gradients, such as boundaries between air and colon wall and/or tissue, are easier to identify. Thus, a shave above a predetermined threshold set, for example at a higher gradient magnitude, becomes the stopping distance of the ray.

In another approach, an air threshold can be used to determine the ray's stopping distance. For example, the scanning device 105 may be calibrated so that air will have a certain value or range of values in the acquired images while soft tissue, such as blood, will have a different value or range of values. After calibrating the scanning device 105, a threshold can be set which falls at the midpoint between the air value and the soft tissue value which is optimal for segmenting the colon and from which the stopping distance of the rays can be determined. In another alternative, when using CAD techniques, only those rays that intersect the "voting surface" of the detected polyp will be used to determine the stopping distance, and thus the shortest ray is selected. The "voting surface" was defined as the intersection of voxels of the colon surface with those voxels leading to polyp detection, which varied with the CAD technique used. This technique is described in a U.S. Patent Application (Attorney Files) entitled "Method and System for Response Image Feature Collection and CandidateSummit, Surface and Core Estimation" No. 2003P08958US), a copy of which is incorporated herein by reference.

As further shown in FIG. 2, once the ray or set of rays is selected, the selected ray or set of rays is used to determine the position and direction for viewing the detected polyp (step 225). In other words, the distance to place the virtual camera away from the polyp and the direction of the camera rotation angle to view the polyp are determined. It will be appreciated that the distance away from the polyp is generally equal to the shortest distance from a central point in the polyp to the surface of the polyp, limited so that the distance remains within the portion of air located in the interior space of the colon. This distance can also be set to a fixed value for all detected and/or marked colons.

The shortest ray and/or group of rays defines the outward direction from the center point of the colon. As a result, the point selected along this shortest ray determines the viewing position in the air part of the colon, and the opposite direction of this shortest ray determines the viewing direction. More precisely, the direction in which the shortest ray is drawn is its inverse, so that the camera is positioned so that the camera looks back at the polyp, as shown in FIG. 3 . For example, the viewing position is determined by extending the shortest ray within the air space of the colon (as shown in FIG. 4A ), and along this ray determines a position that remains within the air space and makes the entire polyp as shown, for example, in FIG. 4A . within the camera's field of view. The shortest ray may extend from the surface of the polyp until either (1) the ray hits the opposite wall of the colon, or (2) the entire polyp is in view, depending on which event occurs first. It should be understood that determining whether the entire polyp is in view depends on the field of view selected for the camera, which is simulated and is the assumed diameter of the polyp. This diameter can be set to a default value, such as one centimeter, or estimated by conventional means.

Figure 4B illustrates another method for determining the location and direction of viewing a detected polyp. As shown in Figure 4B, a spherical set of rays is projected from the surface point of the intersection (at the polyp surface) of the shortest rays. These rays pass through the air until the rays hit a solid surface. The longest ray of the ray group is then used to determine the position and orientation of the virtual camera for viewing. The location is chosen as a point along the ray, which can be a fixed distance within the air region, or it can vary according to the estimated polyp size.

After step 225, the determined position and orientation for viewing the detected polyp is then used to augment an existing procedure or to create a new "hang-through" procedure to pass through the colon or any other lumen body (step 230). Data relating to the determined position and orientation for viewing a detected polyp may be stored, for example, in memory 130 of CPU 125 for further manipulation and/or analysis prior to generating the "fly-through" procedure. Furthermore, given the data obtained at step 225, some additional actions can be generated: (1) the operator of the virtual navigation terminal 115 can use it to immediately view each polyp that has been marked and/or detected, or ( 2) It can be used to provide photography around the polyp to allow the medical professional to view the polyp from multiple sides and/or angles, as shown in FIG. 5 .

Once the "hang-through" has been programmed, the medical professional can follow the "hang-through" route through the colon (step 235). In other words, the operator of the virtual navigation terminal 115 performs the planned or guided navigation according to the "fly-through" of the virtual organ being inspected, as shown in FIG. 6 . As shown in Figure 6, this "air-pass" immediately advances to the first location (A) in the virtual organ (i.e., the first determined location for viewing), thereby bringing the operator directly to The detected polyps were observed. At this point, the "hang-through" will pause and allow the operator to observe the detected polyp (that is, observe the polyp using the determined viewing direction), and then advance to the second position (B) for observation ,etc. Additionally, "fly-through" can provide a plane that intersects the virtual camera so that the virtual camera can automatically move through the virtual environment without operator interaction, yet still allow the operator to manipulate the camera when desired.

According to the invention, the position and orientation for viewing the bump can be automatically determined and used to generate and/or augment a program related to the virtual navigation of the cavity. For example, "fly-through" programmed with position and orientation information in accordance with the present invention enables the operator of the virtual navigation terminal to directly advance to bumps detected using conventional CAD techniques without manually navigating the virtual camera through the cavity. Thus, by using the present invention, conventional CAD systems can be enhanced to generate and/or augment programs associated with virtual navigation of cavities, thereby improving the speed at which users analyze through detected bumps and inspect previously detected bumps thing.

It should be understood that since some system components and method steps described in the drawings can be realized by software, the actual connection between system components (or process steps) may be different according to the way the present invention is programmed. Given the teachings herein of the present invention, one of ordinary skill in the art can contemplate these and similar implementations or configurations of the present invention.

It should be understood that the foregoing description represents exemplary embodiments only. For the convenience of the reader, the foregoing description has focused on representative examples of possible implementations, the examples being illustrative of the principles of the invention. This specification does not attempt to exhaust all possible variations. Alternative embodiments may not have been presented for a particular part of the invention, or other undescribed alternatives may have been used for a part, and these alternative embodiments are not to be regarded as non-claimed. Other applications and embodiments can be implemented directly without departing from the spirit and scope of the present invention. Accordingly, the invention is not intended to be limited by the particularly described embodiments, since many permutations and combinations of what has been described above are possible, including non-inventive substitutions, but the invention is defined in accordance with the appended claims. It should be understood that many of those non-described embodiments are within the literal scope of the appended claims and that others are equivalent.

Claims (47)

1. A method for determining the position and direction of an observation bump, comprising: Casts rays in outward directions from a point that is within the bump; selecting at least one ray from the plurality of rays to determine a location and direction for viewing the bump; and A location and direction for viewing the bump is determined using at least one selected ray of the plurality of rays. 2. The method of claim 1, wherein the plurality of rays are projected into one of a spherical and an ellipsoidal shape. 3. The method of claim 1, wherein the protrusion is one of a nodule, lesion, polyp, precancerous growth, and cancerous growth. 4. The method of claim 1, further comprising: A medical image including the protrusion is obtained. 5. The method of claim 4, wherein the medical images are obtained by computed tomography (CT), helical CT, x-ray, positron emission tomography, fluoroscopy, ultrasound, and magnetic resonance (MR) imaging techniques one of them to obtain. 6. The method of claim 1, further comprising: The bumps were detected using computer-aided bump detection techniques. 7. The method of claim 1, wherein the points are manually selected by a user. 8. The method of claim 1, wherein the point is a center point of the bump. 9. The method of claim 1, wherein a ray of the plurality of rays that experiences the shortest distance from the point to the surface of the bump is selected to determine the location and direction for viewing the bump. 10. The method of claim 9, wherein a plurality of rays that stop at the voting surface of the bump are used to determine the one of the plurality of rays that travels the shortest distance from the point to the surface of the bump. a ray. 11. The method of claim 9, wherein the stopping point of the plurality of rays is determined by the gradient of the image, wherein the stopping point is used to determine the distance from the point to the bump in the plurality of rays. A ray that travels the shortest distance from a surface. 12. The method of claim 9, wherein an air threshold is used to determine a stopping point of the plurality of rays, wherein the stopping point is used to determine a surface of the plurality of rays from the point to the bump A ray that travels the shortest distance. 13. The method of claim 1, wherein a set of rays from the plurality of rays that experience the shortest average distance from the point to the surface of the bump is selected to determine the ray for viewing the bump. position and orientation. 14. The method of claim 1, wherein an opposite direction of the selected at least one ray of the plurality of rays determines a direction for viewing the protuberance. 15. The method of claim 1, further comprising: The determined position and direction for viewing the bump are stored. 16. The method of claim 1, further comprising: The bump is observed from the determined position and direction for viewing the bump. 17. The method of claim 1, wherein the location for viewing the detected bump is determined by selecting a point along an extension direction of at least one selected ray of the plurality of rays. 18. The method of claim 17, wherein the selected point is a point at a fixed distance from the surface of the bump, and the selected longest ray is extended to the fixed distance in air. 19. The method of claim 18, wherein the fixed distance is based on an estimated size of the bump. 20. The method of claim 1, wherein when a surface point on the bump is determined by one of the selected ray and a set of rays, a second plurality of rays are projected from the surface point to the cavity in the air region. 21. The method of claim 20, wherein the second plurality of rays are projected in one of a spherical and ellipsoidal shape. 22. The method of claim 20, wherein the longest ray of the second plurality of rays is selected to determine the location and direction for viewing the bump, wherein the direction for viewing the bump is the same as The direction of the longest ray selected is reversed. 23. The method of claim 22, wherein the location is determined using one of a point along the selected ray and the estimated size of the bump. 24. A system for developing bumps in a medical image comprising: storage devices for storing programs; a processor in communication with the storage device, the processor and the program operative to: Casts rays in outward directions from a point that is within the bump; selecting at least one ray from the plurality of rays to determine a location for viewing the bump; and A location for viewing the bump is determined using at least one selected ray of the plurality of rays. 25. The system of claim 24, wherein a ray of the plurality of rays that traverses the shortest distance from the point to the surface of the bump is selected to determine a location for viewing the bump. 26. The system of claim 24, wherein a set of rays that experience the shortest average distance from the point to the surface of the bump is selected to determine a location for viewing the bump. 27. The system of claim 24, wherein a location for viewing the bump is determined by selecting a point along the direction of extension of at least one selected ray of the plurality of rays. 28. The method of claim 27, wherein the selected point is a point at a fixed distance from the surface of the bump, and the longest ray is extended to the fixed distance in air, wherein the fixed The distance is based on the estimated size of the bump. 29. The system of claim 24, wherein at least one ray is selected from the plurality of rays to determine a direction for viewing the protrusion. 30. The system of claim 29, wherein a ray of the plurality of rays that experiences the shortest distance from the point to the surface of the bump is selected to determine the direction for viewing the bump. 31. The system of claim 29, wherein an opposite direction of at least one selected ray of the plurality of rays determines a direction for viewing the protrusion. 32. The system of claim 29, wherein a set of rays that experience the shortest average distance from the point to the surface of the bump is selected to determine the direction for viewing the bump. 33. The system of claim 29, wherein when a surface point on the bump is determined by one of the selected ray and a set of rays, a second plurality of rays are projected from the surface point to the cavity In the air region of the body, wherein the longest ray of the second plurality of rays is selected to determine the position and direction for viewing the bump, wherein the direction for viewing the bump is consistent with the selected longest ray in the opposite direction. 34. The method of claim 33, wherein the location is determined using one of a point along the selected ray and the estimated size of the bump. 35. A computer program product comprising a computer usable medium having computer program logic recorded thereon to visualize bumps in a medical image, the computer program logic comprising: Program code for casting a plurality of rays into one of spherical and ellipsoidal patterns from a point, where the point is within the bump; program code for selecting at least one ray from the plurality of rays to determine a direction for viewing the bump; and Program code for determining a direction for viewing the bump using at least one selected ray of the plurality of rays. 36. The system of claim 35, wherein a ray of the plurality of rays that experiences the shortest distance from the point to the surface of the bump is selected to determine the direction for viewing the bump. 37. The system of claim 35, wherein a set of rays experiencing the shortest average distance from the point to the surface of the bump is selected to determine the direction for viewing the bump. 38. The system of claim 35, wherein an opposite direction of the selected at least one ray of the plurality of rays determines a direction for viewing the protrusion. 39. The system of claim 35, wherein at least one of the plurality of rays is selected to determine a location for viewing the bump. 40. The system of claim 39, wherein a ray of the plurality of rays that experiences the shortest distance from the point to the surface of the bump is selected to determine a location for viewing the bump. 41. The system of claim 39, wherein a set of rays experiencing the shortest average distance from the point to the surface of the bump is selected to determine a location for viewing the bump. 42. The system of claim 39, wherein the location for viewing the bump is determined by selecting a point along the direction of extension of at least one selected ray of the plurality of rays. 43. The system of claim 42, wherein the selected point is a point at a fixed distance from the surface of the bump, and the longest ray is extended to the fixed distance in air, wherein the fixed distance Based on the estimated size of the bump. 44. The system of claim 39, wherein when a surface point on the bump is determined by one of a selected ray and a set of rays, a second plurality of rays are projected from the surface point to the cavity In the air region of the body, wherein the longest ray of the second plurality of rays is selected to determine the position and direction for viewing the bump, wherein the direction for viewing the bump is the same as the selected most The long rays go in the opposite direction. 45. The system of claim 44, wherein the location is determined using one of a point along the selected ray and the estimated size of the bump. 46. A system for determining the location and direction of a viewing bump comprising: means for projecting rays in an outward direction from a point within the protrusion; means for selecting at least one ray from the plurality of rays to determine a position and direction for viewing the protuberance; and Means for determining a position and direction for viewing the protrusion using at least one selected ray of the plurality of rays. 47. A method for determining the location and orientation of a polyp observed in an image of the colon comprising: obtaining an image of the colon, wherein the image is obtained by one of computed tomography (CT), helical CT, x-ray, positron emission tomography, fluoroscopy, ultrasound, and magnetic resonance (MR) imaging techniques; use computer-aided polyp detection techniques to detect the polyp; projecting a plurality of rays from a point within the polyp, wherein the plurality of rays are projected in one of a spherical and an ellipsoidal pattern; selecting the ray that experiences the shortest distance from the point to the surface of the polyp, wherein selecting a ray of the plurality of rays that experiences the shortest distance from the point to the surface of the polyp to determine the location and direction for viewing the polyp; The selected ray is used to determine the position and direction for observing the polyp, wherein the opposite direction of the selected ray determines the direction for observing the polyp, and the position for observing the polyp is determined along the extension direction of the selected ray selecting a point to determine, wherein the selected point is a point at a fixed distance from the surface of the polyp; and When performing virtual navigation of the colon, the polyp is observed from the determined position and direction for viewing the polyp.

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