Patent Description:
Three-dimensional imaging of biological objects is widely used in medicine, including CT, magnetic resonance imaging and the like. Recently, the use of ultrasound imaging to achieve three-dimensional imaging has also been used more and more. For example, three-dimensional imaging of the fetus and heart has come into the practical use. Ultrasound imaging of bone structures is also evolving. Compared to the heart and fetus, the human bone surface strongly reflects the ultrasound, making it difficult to image the structure below the bone surface, while the bones of the fetus are not calcified, so the ultrasound can penetrate. Therefore, ultrasound, optical tomography, photoacoustic imaging, and other similar methods of imaging an object with a skeletal structure all face this problem. For example, when scanning a human spine bone, a three-dimensional ultrasound scan from the back can only obtain images of the surface of the spinous process bone and the transverse bone but not images of the entire spine bone, because the vertebral body is on the other side, thereby greatly limiting the effect of three-dimensional imaging. On the other hand, we know the approximate shape of each section of spine. In addition, other methods such as CT and MRI can also obtain the basic three-dimensional structure of the spine.

<CIT> discloses a method for three-dimensional presentation of an examination region of a patient as a 3D reconstruction image. All the 2D ultrasound images are obtained and then mixed with the preoperative 3D image dataset. Accordingly, the scanning steps are performed before the mixing step to obtain all the 2D ultrasound images which are needed in the mixing step. Then after all the 2D ultrasound images are obtained, the mixing step is performed for obtaining the updated 3D image dataset. Accordingly, the adjustment step in <CIT> is a one-off thing, which cannot adjust the 3D reconstruction image continuously and in real-time.

<CIT> has disclosed an imaging method for enhancing a visualization of blood vessels in an examination region of a patient, comprising: generating a 3D reconstruction image of the examination region using a preoperatively recorded 3D image dataset of the examination region; recording at least one current 2D image of the examination region by an image recording device; identifying the blood vessels from the 2D image; registering the 3D image dataset with image dataset of the 2D image based on the identification; overlaying the 3D reconstruction image and the 2D image; and playing back the overlaid image. Accordingly, in <CIT> the recording of the at least one current 2D image of the examination region is kept at the same location, and no 3D scanning in different angles is implemented. The information of the current 2D image is limited.

Aiming at the problems of ultrasonic three-dimensional imaging existing in the prior art, a three-dimensional imaging of a biological object is proposed, which can utilize the basic three-dimensional structure of the biological object on the one hand and utilize such as the ultrasound technology to perform two-dimensional scanning imaging on biological objects on the other hand.

It is the object of this invention to provide a three-dimensional imaging method for biological objects, which can reduce the scanning operation required for imaging and the use of radiation imaging methods on organisms thus reducing damage to living organisms.

This object is achieved by the subject matter of independent claim <NUM>.

Preferred embodiments of the invention are the subject matter of the dependent claims.

By implementing the target-oriented three-dimensional imaging method and system provided by the present application, the three-dimensional imaging can be assisted by using known approximate three-dimensional structures of the scanning target and the adjustment of the two-dimensional images. The method of the present application can also be applied to other similar imaging methods, such as optical tomography, photoacoustic imaging, terahertz imaging, and the like. Since the three-dimensional imaging of the present application adopts target orientation, only some initial information of the imaging target should be needed. For example, when the imaging target is a certain bone of the human body, its approximate original shape can be known, but its specific size, position and detail cannot be got. Using the method of the present application, by means of continuously scanning the position of the target though the two-dimensional imaging, and adjusting the original shape of the target; the specific size, position and detail of the target are obtained, and an overall three-dimensional image of the target is formed. During the scanning process, the operator can continuously see the progress of the scanning through the display device, including the portions that have been scanned, the portions that have not been scanned and the quality of the images, so that useful feedback information can be obtained to guide further scanning.

In the first embodiment of the method of the present application, as shown in <FIG>, the target-oriented three-dimensional imaging method provided by the present application includes the following steps.

Step <NUM>) determining, on a scanning object, a portion comprising a scanning target using three-dimensional scanning
When performing the three-dimensional imaging of a specific patient scanning target, a scanning range <NUM> may be given according to the estimated scanning target position <NUM>. As shown in <FIG>, <NUM> is the estimated scanning target position, <NUM> is the given scanning range, and <NUM> is an area including the scanning target. In other words, for objects requiring three-dimensional imaging, the position to be scanned can be first estimated based on experience. For this, a scanning range <NUM> can be given on the human body or other living organisms, which can cover the position <NUM> of the estimated scanning target, and the area <NUM> is an area including the scanning target, as shown in <FIG>.

Step <NUM>) on the basis of the determined portion of the scanning object, forming an existing initial three-dimensional structure of the scanning target from a database
On the basis of the scanning range given in the step <NUM>, a three-dimensional structure is extracted from the database pre-storing the three-dimensional structure of the scanning target as the initial three-dimensional structure <NUM> of the scanning target. As shown in <FIG>, in the given scanning range <NUM>, the initial three-dimensional structure image <NUM> of the scanning target is put. Wherein, the initial three-dimensional structure of the scanning target corresponding to the three-dimensional structure image <NUM> can be a known representative three-dimensional anatomical structure of a certain portion of human body which is pre-acquired and stored in a database. It also can be representative three-dimensional anatomical structures corresponding to human bodies of different ages and genders which are pre-acquired and stored in a database, or further can a be three-dimensional anatomical structure pre-obtained by other means and stored in a database. The other means include performing a CT or MRI scan on the scanning target of human body. Among them, the three-dimensional structure of different sources should have a data structure with uniform standards.

<FIG> is a cross-sectional view showing the three-dimensional structure image of the initial form of the scanning target read from the database in the present embodiment.

Step <NUM>) through ultrasound imaging technology, scanning the portion comprising the scanning target to form a series of two-dimensional images with different spatial location and/or orientation information
Since the two-dimensional imaging can be performed within a given scan range from various angles, the most characteristic information about the scanning target can be obtained, as although some characteristic information may not be clearly imaged from one direction, however it may be clearer when imaging from another direction. Step <NUM> indicates that the two-dimensional imaging obtains as much information as possible by giving different directions and positions.

<FIG> is an image obtained by two-dimensional ultrasound imaging at the same position of <FIG>. As the high-frequency ultrasound cannot penetrate the bone, the lower portion of the bone structure cannot be imaged. When comparing the two images, the structure of the scanning target can be globally or locally adjusted according to the curve ratios obtained from the corresponding positions.

Step <NUM>) referring to image information related to the scanning target or a local portion of the scanning target within an image, adjusting the initial three-dimensional structure of the scanning target or the local portion of the scanning target
In step <NUM>), the image information for controlling the adjustment comprises a characteristic point, a characteristic line, a characteristic face, a characteristic body of the scanning target or the local portion of the scanning target, or a combination thereof.

The point on the scanning target as shown in <FIG> may be some characteristic points on the scanning target, such as characteristic points formed on the image by human bones. <FIG> shows the spinous process apex <NUM> of the spine bone (scanning target) as a characteristic point of the spine bone.

The line on the scanning target as shown in <FIG> may be some characteristic lines on the scanning target, for example, a straight line <NUM> formed on the image by the human bone. As shown in <FIG>, the characteristic line may be a straight line or a curved line.

The surface on the scanning target shown in <FIG> may be some characteristic surfaces <NUM> on the scanning target. The characteristic surface may be a plane or a curved surface. The characteristic surface <NUM> shown in <FIG> is a curved characteristic surface.

The body on the scanning target as shown in <FIG> may have some characteristic body <NUM>.

Based on the characteristic points, lines, faces, and bodies of the scanning target, the adjustments including global or local translation, rotation, scaling, and or a combination thereof can be performed on the scanning target, for example, simultaneously panning and zooming.

Step <NUM>) repeating steps S3) and S4) until the initial three-dimensional structure of the scanning target has been adjusted based on the obtained images
The adjustment of the image here can be done off-line and completed after all the images are collected, reducing the time spent on the scanning target during scanning.

Step <NUM>) displaying a final three-dimensional structure image of the scanning target after adjustment on a display device
The final three-dimensional structure image of the scanning target further comprises a characteristic label used by the adjustment.

The second embodiment comprises following steps:.

The adjustment on the image in the steps <NUM>-<NUM>) can be done off-line once after all the images are collected, which can reduce the scanning time.

In another embodiment, which is different from the second embodiment described above in that the adjustment in step <NUM> is a deformable adjustment, that is, the scanning of the target starts from the initial three-dimensional result, and each portion can be individually adjusted according to the information obtained in the image scanning, so that the various portions of the adjusted scanning target are not simply scaled. Deformable scaling is particularly useful for spinal bone distortion.

In another embodiment, which is different from the second embodiment described above in that after the three-dimensional structure is adjusted in step <NUM>, a step may be added in which the three-dimensional structure of the adjusted scanning target is displayed in the display device each time. The operator can continuously see the progress of the scan, including the portion that has been scanned and the portion that has not been scanned, and the quality of the image, so that useful feedback information can be obtained to guide the further scanning.

In another embodiment, which is different from the second embodiment described above in that the final three-dimensional structure image of the scanning target in the step S6) further comprises a characteristic label used by the adjustment to facilitate the adjustment operation.

In the embodiment of a three-dimensional imaging system of the present application illustrated in <FIG>, the following components are comprised: <NUM>) an imaging device <NUM> for acquiring two-dimensional images of a scanning target on a determined portion, in this embodiment, this imaging device can be an ultrasound scan imaging device; <NUM>) a space locating device <NUM> for acquiring spatial location and angle of each two-dimensional image from the imaging device; when the imaging device performs continuous scanning imaging on the determined portion, the space locating device <NUM> records the corresponding two-dimensional images formed by the scanning imaging as a basis for adjusting the initial three-dimensional structure; <NUM>) a database <NUM> for providing an initial three-dimensional structure of the scanning target; here, all kinds of the initial three-dimensional structure database of the scanning target are pre-stored in the database; <NUM>) a feature extraction unit <NUM> for extracting characteristic information in the two-dimensional images or three-dimensional images formed by the two-dimensional images; the characteristic information here can be a point, a line, a face or a body; <NUM>) an adjustment unit <NUM> for adjusting the initial three-dimensional structure of the scanning target using the characteristic information; the adjustment here comprises one or more of the spatial location, orientation, size, and relative proportion; <NUM>) a display device <NUM> for displaying the two-dimensional images and a three-dimensional structure of the scanning target. When obtaining the initial three-dimensional structure from the database, the display device <NUM> displays the three-dimensional structure image; while when obtaining the two-dimensional images from the imaging device <NUM>, the display device <NUM> displays the two-dimensional images. When obtaining the three-dimensional structure adjusted by the adjustment unit <NUM>, the display device <NUM> displays the three-dimensional structure image adjusted with the characteristic information.

Claim 1:
A three-dimensional imaging method, comprising the following steps:
S1) determining, on a scanning object, a scanning range covering a portion comprising a scanning target for a three-dimensional scanning;
S2) on a basis of the scanning range of the scanning object, extracting an existing initial three-dimensional structure (<NUM>) of the scanning target from a database;
S3) scanning the portion comprising the scanning target within the given scanning range from various angles to form a series of two-dimensional images with different spatial location and orientation information;
S4) according to image information related to the scanning target or a local portion of the scanning target within the series of two-dimensional images, adjusting the initial three-dimensional structure (<NUM>) of the scanning target or the local portion of the scanning target;
S5) repeating steps S3) and S4) until the whole initial three-dimensional structure (<NUM>) of the scanning target has been scanned over and is adjusted, based on the obtained two-dimensional images, and an overall three-dimensional structure image of the target is formed
S6) continuously displaying the initial three-dimensional structure (<NUM>) of the scanning target and the adjusted three-dimensional structure image during the two-dimensional scanning imaging process on a display device (<NUM>);
S7) displaying the final three-dimensional structure image of the scanning target after the adjustments.