CN103123721B - Method and device for reducing artifacts in image in real time - Google Patents

Abstract

The invention provides a method for reducing artifacts in images in real time, which comprises the following steps: acquiring a reference image: moving an ultrasonic probe at a treatment position to a position for acquiring a reference image, and acquiring an image of a focus at the reference image position as the reference image, wherein the reference position is a certain position which can enable part of an image acquired by the ultrasonic probe corresponding to a treatment target area to have fewer artifacts or no artifacts; acquiring a treatment image: moving the ultrasonic probe from the reference position back to the treatment position, and acquiring a current treatment image of the lesion; and (3) registration and fusion of images: and registering and fusing the acquired treatment image and the reference image, and outputting a fused image, wherein the image is the actual treatment image. Accordingly, an apparatus for reducing artifacts in images in real time is provided. The method and the device for reducing the artifacts in the images in real time can improve the positioning precision of the ultrasonic probe on the target area to be treated, thereby improving the treatment efficiency and treatment effect of the ultrasonic guided surgery.

Description

A method and device for reducing artifacts in images in real time

technical field

The invention belongs to the technical field of image processing, and in particular relates to a method for reducing artifacts in images in real time and a device for reducing artifacts in images in real time.

Background technique

High Intensity Focused Ultrasound (HIFU) technology is a non-invasive treatment method, which is currently mainly used in the treatment of breast cancer, solid benign and malignant tumors in the abdominal cavity and pelvic cavity. The treatment principle of HIFU technology is to use high-intensity ultrasound focused on biological tissue to make the temperature of the tissue within the focal area reach 60 degrees Celsius or more in an instant, causing coagulation necrosis in the tissue within the focal area instantaneously, and at the same time, the tissue outside the focal area has no effect. significant damage. Ultrasound has become the monitoring method in about 90% of HIFU treatment systems on the market because of its advantages of real-time and low cost.

In the ultrasound-guided HIFU treatment system, it is required to minimize the damage to normal tissues, so the location and shape of the lesion need to be determined before the treatment. During the treatment, the treatment effect can be observed in real time to adjust the treatment dose and timely To interrupt the treatment, in order to realize the above functions, the HIFU treatment system generally adopts a combined probe, which is composed of a treatment head that emits ultrasonic waves for treatment and a B-ultrasound or color Doppler ultrasound imaging probe (hereinafter referred to as the ultrasonic probe).

Usually, due to the large size of the combined probe, in order to reduce the reflection of the ultrasonic wave entering the human tissue from the outside, as well as heat dissipation and energy gathering during the operation, in the HIFU treatment system, the entire combined probe is soaked in the coupling agent. in degassed aqueous medium. When performing treatment, the skin at the patient's lesion is coupled with the coupling agent, and is imaged by an ultrasonic probe to observe the exact position and specific shape of the patient's lesion, and at the same time accurately position the focal area of the treatment head on the patient's lesion, so as to implement the treatment . Since there is a degassed water medium between the combination probe in the HIFU treatment system and the skin of the patient's lesion, the ultrasound probe in the combination probe is far away from the human body surface during imaging, so the diagnostic ultrasound emitted by the ultrasound probe will be in the Multiple reflections occur between the skin of the human body and the surface of the treatment head and the ultrasonic probe, so that the ultrasonic probe receives multiple repeated signals, and the echoes generated by the multiple reflections are mixed with the ultrasound entering the internal tissues of the human body, resulting in HIFU treatment system Artifacts exist in the ultrasound image (hereinafter referred to as the image) acquired by the ultrasound probe in .

The image artifacts in the HIFU treatment system have brought many adverse effects to the HIFU treatment system, such as:

1. Artifacts prevent the anatomical information of biological tissues from being accurately reflected on the image, which increases the possible risks during HIFU treatment and correspondingly increases the experience requirements for operators during HIFU treatment;

2. The appearance of artifacts makes some tumors with too serious artifacts unable to be treated, thus limiting the range of diseases and populations treated by the ultrasound-guided HIFU treatment system;

3. At present, gray enhancement is generally used to judge and treat injuries, and the existence of artifacts may affect the operator's observation of tissue damage in the treatment area in the image;

4. The artifact problem reduces the performance and safety factor of the overall HIFU treatment system.

Contents of the invention

The technical problem to be solved by the present invention is to provide a method and device capable of reducing artifacts in images in real time for the above-mentioned problems in the prior art, which can improve the positioning accuracy of the ultrasonic probe to the treatment target area, thereby improving the accuracy of ultrasound-guided surgery. treatment efficiency and efficacy.

The technical solution adopted to solve the technical problems of the present invention is:

The method for reducing artifacts in an image in real time comprises the steps of:

1) Acquiring a reference image: move the ultrasonic probe at the treatment position to the position for acquiring a reference image, and acquire an image of the lesion at the position of the reference image as a reference image, and the reference position is one of the images that can be acquired by the ultrasonic probe. A certain position corresponding to the treatment target area with less or no artifacts. The treatment position refers to when the ultrasonic probe is at this position, the operator can observe the ultrasonic image of the area to be treated in real time, and requires the treatment head The focus is within the treatment area;

2) Acquiring treatment images: moving the ultrasound probe back from the reference position to the treatment position, and acquiring current treatment images of the lesion;

3) Image registration and fusion: the collected treatment images are registered and fused with the reference image, and a fused image is output, which is the actual treatment image.

Preferably, in step 1), it is first judged whether there are more artifacts in the image collected by the ultrasonic probe at the treatment position, if there are more artifacts, then according to the position of the skin line in the image collected by the ultrasonic probe from the treatment Move the ultrasonic probe along the direction close to the skin until the ultrasonic probe moves to a position with a distance of 0-5 cm from the skin, that is, the ultrasonic probe moves to the reference position, stops moving the ultrasonic probe, and collects reference images of lesions at the reference position. image.

Preferably, in step 1), the collected reference images are multiple time-continuous reference images, and the multiple time-continuous reference images constitute a reference image sequence; while collecting the reference image sequence, the patient's physiological signal, and introducing said physiological signal into a reference image sequence;

In step 2), while collecting the treatment image, the physiological signal of the patient is collected, and the physiological signal is introduced into the current treatment image.

Further preferably, in step 1), the process of acquiring the reference image sequence is as follows: acquiring multiple sets of image sequences of multiple consecutive physiological signal periods, and each physiological signal period corresponds to a set of image sequences, and checking the Whether each group of image sequences acquired by the signal cycle is consistent or basically consistent, if consistent or basically consistent, select a group of image sequences of one of the physiological signal cycles as the reference image sequence; if inconsistent or not basically consistent, continue to collect the next The image sequence of the first physiological signal cycle is compared with the image sequence of the last physiological signal cycle until the multiple groups of image sequences collected for multiple consecutive physiological signal cycles are consistent or basically consistent, and then the multiple consecutive physiological signal cycles are selected. Any one of multiple sets of image sequences of the physiological signal cycle is used as a reference image sequence.

Preferably, in step 1), in the plurality of continuous physiological signal periods, each physiological signal period includes several different phases, according to the number of phases in a corresponding physiological signal period when the reference image sequence is collected. different phases, associating each reference image in the reference image sequence with a different phase in the corresponding physiological signal cycle is to introduce the physiological signal into the reference image sequence;

In step 2), according to a different phase in a corresponding physiological signal cycle when the therapeutic image is collected, associating the current therapeutic image with a different phase in the corresponding physiological signal cycle is Physiological signals are introduced into the current therapy image.

Preferably, in step 3), the collected current treatment image is registered and fused with the reference image in the reference image sequence, and the fused image is output in real time, and then the treatment image at the next moment is continued to be collected. It registers and fuses with the reference image in the reference image sequence, and outputs the fused image in real time, so that the continuous output of the actual treatment image can be obtained through a cycle like this.

Preferably, in step 1), the spatial position of the ultrasonic probe is recorded when the ultrasonic probe is in the treatment position, and the spatial position of the ultrasonic probe is recorded when the ultrasonic probe is in the reference position;

In step 3), the registration and fusion of images are:

31) Perform physiological signal registration on the current treatment image that has introduced physiological signals and a reference image in the reference image sequence that has introduced physiological signals through a physiological signal registration algorithm, and the reference image and the current treatment image The phases of the two phases are the same, and the reference image after the registration of the physiological signal is output in real time, and then according to the different spatial positions of the ultrasound probe when the reference image sequence is collected and the current treatment image, the reference image after the registration of the physiological signal is compared with the current treatment image. Spatial registration is performed on the treatment images, and the reference images after spatial registration are output;

Or, according to the different spatial positions of the ultrasound probe when acquiring the reference image sequence and the current treatment image, spatially align the current treatment image into which the physiological signal has been introduced and all reference images in the reference image sequence into which the physiological signal has been introduced. and output the reference image sequence after the spatial registration is completed, and then use the physiological signal registration algorithm to integrate the current treatment image that has introduced the physiological signal and the reference image sequence that has introduced the physiological signal and completed the spatial registration. Physiological signal registration of a reference image, and the reference image has the same phase as the current treatment image, and output the reference image after the physiological signal registration is completed;

32) Real-time fusion of the reference image with the completed physiological signal registration and spatial registration and the current treatment image, and output the fused image in real time.

Further preferably, in step 31), the method for performing spatial registration between the current treatment image and the reference image is: converting the coordinate difference between the spatial position when the ultrasonic probe acquires the reference image and the spatial position when the current treatment image is acquired into the The pixel difference between the reference image and the current treatment image, and complete the spatial registration of the current treatment image and the reference image according to the pixel difference;

In step 32), when fusing the reference image with the treatment pattern, all or only the part containing the treatment target area in the reference image is selected for real-time fusion with the current treatment image, and the fusion method adopts the average gray level value method or pixel gray level product method.

More preferably, in step 31), the spatial registration method is specifically:

The spatial position coordinates when the ultrasonic probe collects the current treatment image is set as P1 (x1, y1, z1), and the spatial position coordinates when the ultrasonic probe collects the reference image is set as P2 (x2, y2, z2) ;

Assuming that the ultrasonic probe moves in the yz plane, then x1=x2, the coordinate difference between point P1 and point P2 is dy=y1-y2, dz=z1-z2;

Assuming that the size of each pixel in the current treatment image and the reference image is m×n, when spatially registering the current treatment image and the reference image, the reference image is moved by dy/m pixels in the y direction, and the z Move the reference image by dz/n pixels in the direction to complete the spatial registration of the current treatment image and the reference image;

In step 32), the fusion method specifically includes: when selecting a part of the reference image that only includes the treatment target area and performing real-time fusion with the current treatment image, if a certain point in the reference image exceeds the selected range, there is no need for fusion, and the gray value of the corresponding point in the current treatment image is directly output as the gray value of the fused image.

Preferably, the physiological signal registration algorithm includes a signal preprocessing algorithm and a signal registration algorithm, and the signal preprocessing algorithm is to normalize the real-time collected and processed physiological signals; the signal registration algorithm A dynamic temporal convolution algorithm is used.

Preferably, when the lesion is greatly affected by respiration, the one physiological signal cycle is a respiration signal cycle; when the lesion is greatly affected by heartbeat, the one physiological signal cycle is a heartbeat signal Period; when the lesion is affected by respiration and heartbeat at the same time, and the degree of influence is relatively large, the one physiological signal period is one respiration signal period.

A device for reducing artifacts in images in real time, the device comprising: an image registration unit, an image fusion unit, and a display unit,

The image registration unit is configured to receive the reference image collected by the ultrasound probe at the reference position and the treatment image collected at the treatment position, register the reference image collected by the ultrasound probe with the treatment image, and real-time register the reference image after registration. output;

An image fusion unit, configured to receive the registered reference image output by the image registration unit, perform real-time fusion of the registered reference image and the treatment image, and output the fused image in real time;

The display unit is used to receive and display the image output by the image fusion unit.

Preferably, the device further includes a physiological signal acquisition unit, and the reference images collected by the ultrasonic probe are multiple time-continuous reference images, and the multiple time-continuous reference images are multiple consistent or Any set of image sequences among multiple sets of image sequences with basically consistent continuous physiological signal cycles, the image sequence is the reference image sequence,

The physiological signal acquisition unit is used to collect the physiological signals of the patient in real time, and is used to receive the reference image collected by the ultrasonic probe at the reference position and the current treatment image collected at the treatment position, and then introduce the collected physiological signals of the patient into the ultrasound In the reference image sequence collected by the probe at the reference position and the current treatment image collected at the treatment position, the reference image sequence of the patient’s physiological signal and the current treatment image are then output to the image registration unit in real time, and the One of the sequence of reference images in which the patient's physiological signal has been introduced is registered with the current treatment image in which the patient's physiological signal has been introduced, and then the registered reference image is output to the image fusion unit in real time.

Preferably, the device also includes a motion unit and a control unit,

A motion unit for moving the ultrasound probe;

The control unit is used for instructing the motion unit to move the ultrasonic probe according to the information input from the outside.

Preferably, the image registration unit includes a physiological signal registration module and a spatial registration module,

The control unit is also used to record the spatial position of the ultrasonic probe when the ultrasonic probe is at the treatment position, record the spatial position of the ultrasonic probe when the ultrasonic probe is at the reference position, and record the recorded acquisition reference image sequence and current treatment image The spatial position signals of the probes are output to the spatial registration module,

The physiological signal registration module is used to receive the reference image sequence of the introduced patient's physiological signal and the current treatment image of the introduced patient's physiological signal, and combine the introduced current treatment image of the patient's physiological signal with the introduced patient's physiological signal Physiological signal registration is performed on a reference image in the reference image sequence of the physiological signal, and the phase of the reference image is the same as that of the current treatment image, and then the reference image after the physiological signal registration is completed is output to the spatial registration module in real time ,

The spatial registration module is used to receive the reference image output by the physiological signal registration module after the physiological signal registration is completed, and according to the different spatial positions of the ultrasonic probe transmitted by the control unit when acquiring the reference image sequence and the current treatment image performing spatial registration on the reference image after the physiological signal registration is completed and the current treatment image, and outputting the reference image after the spatial registration to the image fusion unit in real time;

Alternatively, the spatial registration module is used to receive different spatial position signals of the ultrasonic probe transmitted by the control unit when acquiring the reference image sequence and the current treatment image, and accordingly align the current treatment image and all the images in the reference image sequence in a spatial alignment. Registration, and then real-time output of the reference image sequence after spatial registration is completed to the physiological signal registration module;

The physiological signal registration module is used to receive the spatially registered reference image sequence output by the spatial registration module, and combine the current treatment image of the introduced patient's physiological signal and the introduced patient's physiological signal Physiological signal registration is performed on a reference image in the reference image sequence, and the phase of the reference image is the same as that of the current treatment image, and the registered reference image is output to the image fusion unit in real time.

Preferably, the spatial registration module is used to convert the coordinate difference between the spatial position of the ultrasonic probe when acquiring the reference image and the spatial position when acquiring the current treatment image into a pixel difference between the reference image and the current treatment image, The spatial registration of the current treatment image and the reference image is completed according to the pixel difference; the image fusion unit is used to select all of the registered reference image or only the part containing the treatment target area and the current treatment The images are fused in real time.

The method for reducing artifacts in images in real time according to the present invention significantly reduces the artifacts in the output image after the treatment image and the reference image are registered and fused. Experiments show that the method of the present invention can reduce the area of interest to the doctor. All the artifacts in the image (such as the treatment target area) are eliminated, and the overall artifacts in the overall image are reduced by more than 70%. At the same time, the edge definition of the output image is improved, so that the information of the patient's treatment target area is obtained on the image. More accurate reflection, thereby improving the positioning accuracy of the ultrasound probe to the treatment target area, and also improving the treatment efficiency and treatment effect of ultrasound-guided treatment operations. The method for reducing artifacts in images in real time can reduce The risk of surgery, thus expanding the scope of application of the HIFU treatment system.

Description of drawings

FIG. 1 is a flowchart of a method for reducing artifacts in an image in real time in Embodiment 1 of the present invention;

FIG. 2 is a schematic structural diagram of a device for reducing artifacts in an image in real time in Embodiment 1 of the present invention;

Fig. 3 is a flowchart of a method for reducing artifacts in an image in real time according to Embodiment 2 of the present invention.

detailed description

In order to enable those skilled in the art to better understand the technical solutions of the present invention, the method and device for reducing artifacts in images in real time according to the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

The method for reducing artifacts in an image in real time comprises the steps of:

1) Collect reference images: move the ultrasonic probe from the treatment position to the reference position, and collect images of the lesion at the reference position as the reference image, the reference position is the part corresponding to the treatment target area in the image collected by the ultrasonic probe A certain position with less or no artifacts;

2) Acquiring treatment images: moving the ultrasound probe back from the reference position to the treatment position, and acquiring current treatment images of the lesion;

3) Image registration and fusion: the collected treatment images are registered and fused with the reference image, and a fused image is output, which is the actual treatment image.

The device for reducing artifacts in images in real time includes: an image registration unit, an image fusion unit, and a display unit,

The image registration unit is configured to receive the reference image collected by the ultrasound probe at the reference position and the treatment image collected at the treatment position, register the reference image collected by the ultrasound probe with the treatment image, and real-time register the reference image after registration. Output to the image fusion unit;

An image fusion unit, configured to receive the registered reference image output by the image registration unit, fuse the registered reference image and the treatment image in real time, and output the fused image to the display unit in real time;

The display unit is used to receive and display the image output by the image fusion unit.

Example 1:

In this embodiment, the method for reducing artifacts in an image in real time includes:

1) Acquisition of reference images:

Move the ultrasonic probe to a position suitable for treatment and collect images of the current lesion. The treatment position means that when the ultrasonic probe is at this position, the operator can observe the ultrasonic image of the area to be treated in real time, and requires the treatment head to focus In the treatment area, record the spatial position of the ultrasonic probe at the treatment position at the same time, first judge whether there are many artifacts in the image of the lesion collected by the ultrasonic probe at the treatment position, if there are many artifacts, then according to the ultrasound In the image collected by the probe, the position of the skin line (the surface of the human skin appears as a curve on the section plane of the ultrasound image, and the curve is the skin line) moves the ultrasound probe from the treatment position along the direction close to the skin until the ultrasound probe moves to the position in line with the skin. When the distance between the skin is 0-5cm, the part of the image collected by the ultrasonic probe corresponding to the treatment target area has less or no artifacts, and the image quality is higher. Stop moving the ultrasonic probe at this moment and set the ultrasonic probe to The position is the reference position for acquiring the reference image, and the spatial position of the ultrasound probe at the position of the reference image is recorded at the same time, and the reference image of the lesion is acquired at the reference position.

There are many artifacts in the image of the lesion collected by the ultrasonic probe at the treatment position because: the ultrasonic probe is at the treatment position at a certain distance from the body surface of the human body, so the ultrasonic waves emitted by the ultrasonic probe are transmitted between the ultrasonic probe and the human body. There are multiple reflections with the treatment head, so that the ultrasonic probe receives multiple repeated signals, resulting in more artifacts in the collected images, which seriously affects the image quality. When the ultrasonic probe moves along the direction close to the skin, The scope of the ultrasonic reflection is gradually reduced, and the artifacts in the images collected are also gradually reduced. When the ultrasonic probe is close to the skin, the multiple reflections of the ultrasonic waves are eliminated, and the artifacts in the images collected by the ultrasonic probe disappear. .

When the ultrasonic probe is in close contact with the skin, the images collected by the doctor in the area of interest (such as the treatment target area, that is, the area where the patient needs to be treated, generally the lesion in the organ and where safe treatment can be implemented) Artifacts disappear in , and there may still be artifacts in areas not of interest to doctors, but since such artifacts do not affect treatment, they can be ignored. The images with less or no artifacts are collected as reference images for registration and fusion with subsequent treatment images collected by the ultrasound probe at the treatment position, which can effectively reduce the artifacts in the output image after fusion.

The reference images collected at the reference position are multiple temporally continuous reference images, and the multiple temporally continuous reference images constitute a reference image sequence. Specifically, since the patient's signs may be unstable during treatment, such as shortness of breath or rapid heartbeat, etc., resulting in different periods of physiological signals in different periods, it is necessary to collect multiple sets of images of multiple continuous physiological signal cycles sequence, and each physiological signal cycle corresponds to a group of image sequences, and check whether the image sequences of each group of image sequences collected in each physiological signal cycle are consistent or basically consistent, and if they are consistent or basically consistent, select one of the physiological signal cycles The group image sequence is used as the reference image sequence; if it is inconsistent or not basically consistent, continue to collect the image sequence of the next physiological signal cycle, and compare it with the image sequence of the previous physiological signal cycle until multiple consecutive physiological signal cycles are collected. The multiple sets of image sequences of the signal periods are consistent or substantially consistent, and any one of the multiple sets of image sequences of the multiple continuous physiological signal periods is selected as a reference image sequence.

While acquiring the reference image sequence, the physiological signal of the patient is acquired, and the physiological signal is introduced into the reference image sequence. In the plurality of continuous physiological signal cycles, each physiological signal cycle includes several different phases, and according to the several different phases in a corresponding physiological signal cycle when the reference image sequence is acquired, the reference Correlating each reference image in the image sequence with a different phase in the corresponding period of the physiological signal is to introduce the physiological signal into the reference image sequence.

2) Acquisition of treatment images:

The ultrasound probe is moved back from the reference position to the treatment position, and a current treatment image of the lesion is collected. While acquiring the current treatment image, the physiological signals of the patient are acquired and introduced into the current treatment image. According to a different phase in a corresponding physiological signal cycle when the therapeutic image is collected, associating the current therapeutic image with a different phase in the corresponding physiological signal cycle is to introduce the physiological signal into the current therapeutic image.

3) Image registration and fusion:

Register and fuse the collected current treatment image with the reference image in the reference image sequence, and output the fused image in real time, which is the current actual treatment image, and then continue to collect the treatment image at the next moment , register and fuse it with the reference image in the reference image sequence, and output the fused image in real time, so that the continuous output of the actual treatment image can be obtained.

The reason for performing physiological signal registration on the current treatment image and the reference image in the reference image sequence is:

Since the patient's lesions (organs in the treatment target area) will undergo periodic real-time deformation due to the influence of physiological signal factors such as breathing or heartbeat, the ultrasound probe may be in a different position when collecting the reference image and the current treatment image in the treatment target area. The different phases in the physiological signal cycle cause deviation or deformation between the collected reference image and the current treatment image, so that the reference image and the current treatment image cannot be fused in real time to reduce artifacts in the fused output image.

In order to solve the above problems, it is necessary to introduce physiological signals into the reference image sequence and the current treatment image respectively, so that each reference image in the current treatment image and the reference image sequence corresponds to a phase in a physiological signal cycle. Through phase matching, It can effectively eliminate the deviation or deformation between the reference image and the current treatment image caused by physiological signal factors such as breathing or heartbeat.

The reasons for spatially registering the current treatment image and the reference images in the reference image sequence are:

When the reference image and the current treatment image are collected, the spatial position of the ultrasonic probe is different, so that the collected reference image cannot completely correspond to the current treatment image, and there is a position deviation. At this time, spatial registration between the reference image and the current treatment image is required. , to eliminate the positional deviation.

Specifically, the method for registering the current treatment image with the reference image in the reference image sequence is as follows:

Physiological signal registration is performed on the current treatment image that has introduced physiological signals and a reference image in the sequence of reference images that have introduced physiological signals through a physiological signal registration algorithm, and the phase of the reference image and the current treatment image The same, and output the reference image after the physiological signal registration in real time, and then according to the different spatial positions of the ultrasonic probe when collecting the reference image sequence and the current treatment image, the reference image after the physiological signal registration is completed and the current treatment image Carry out spatial registration, and output the reference image after the spatial registration is completed;

Or, according to the different spatial positions of the ultrasound probe when acquiring the reference image sequence and the current treatment image, spatially align the current treatment image into which the physiological signal has been introduced and all reference images in the reference image sequence into which the physiological signal has been introduced. and output the reference image sequence after the spatial registration is completed, and then use the physiological signal registration algorithm to integrate the current treatment image that has introduced the physiological signal and the reference image sequence that has introduced the physiological signal and completed the spatial registration. Physiological signal registration is performed on a reference image, and the phase of the reference image is the same as that of the current treatment image, and the reference image after the physiological signal registration is completed is output.

Wherein, the physiological signal registration algorithm includes a signal preprocessing algorithm and a signal registration algorithm, and the signal preprocessing algorithm is to normalize the real-time collected and processed physiological signals; the signal registration algorithm adopts a dynamic Time Convolution (DTW) algorithm.

Wherein, the method for spatial registration of the current treatment image and the reference image is:

Convert the coordinate difference between the spatial position when the ultrasonic probe collects the reference image and the spatial position when the current treatment image is collected into the pixel difference between the reference image and the current treatment image, and complete the current treatment image and the reference treatment according to the pixel difference. Spatial registration of images.

The spatial registration method is specifically:

The spatial position coordinates when the ultrasonic probe collects the current treatment image is set as P1 (x1, y1, z1), and the spatial position coordinates when the ultrasonic probe collects the reference image is set as P2 (x2, y2, z2) ; Since the ultrasonic probe only needs to move in one plane when collecting reference images and current treatment images, assuming that the ultrasonic probe moves in the yz plane, then x1=x2, the coordinate difference between P1 and P2 is dy=y1-y2 , dz=z1-z2; assuming that in the current treatment image and the reference image, the size of each pixel is m×n, then when the current treatment image and the reference image are spatially registered, the reference image is moved in the y direction by dy/ By moving the reference image by dz/n pixels in the z direction by m pixels, the spatial registration between the current treatment image and the reference image is completed. The same applies when the ultrasonic probe needs to move in the xz and xy planes.

Then, the reference image that has completed the physiological signal registration and spatial registration is fused with the current treatment image in real time, and the fused image is output in real time.

When fusing the reference image with the treatment graphic, all or only the part containing the treatment target area in the reference image is selected for real-time fusion with the current treatment image. When selecting the part of the reference image that only includes the treatment target area and the current treatment image for real-time fusion, if a certain point in the reference image exceeds the selected range, no fusion is required, and the current treatment image is directly output The gray value of the corresponding point in is used as the gray value of the fused image.

In this embodiment, the fusion method adopts the average gray value method or the pixel gray value product method.

The average gray value method is specifically:

Assuming that the gray value of a certain pixel point P2 in the reference image is g2, and the gray value of the pixel point P1 corresponding to point P2 in the reference image in the current treatment image is g1, then the image after fusion and P1 , The gray value of the pixel point P3 corresponding to the point P2 is g3=(g1+g2)/2.

The pixel gray level product method is specifically:

Assuming that the gray value of a certain pixel point P2 in the reference image is g2, and the gray value of the pixel point P1 corresponding to point P2 in the reference image in the current treatment image is g1, then the image after fusion and P1 , The gray value of the pixel point P3 corresponding to the point P2 is g3=sqrt(g1*g2).

According to the patient's lesion is affected by respiration and/or heartbeat, when the lesion is greatly affected by respiration, the one physiological signal period is one respiration signal period. In this embodiment, the patient's lesion is greatly affected by respiration, so several image sequences of several consecutive respiration signal periods are collected, and one of them is selected as a reference image sequence. As shown in Figure 1, the specific steps of the method for reducing artifacts in an image in real time are as follows:

s101. Move the ultrasound probe to the treatment position and collect images of the current lesion, and record the spatial position of the ultrasound probe at this time;

s102. Judging whether there are many artifacts in the treatment image collected by the current ultrasonic probe, if yes, execute s103, if not, execute s113;

s103. Detect whether the reference image sequence containing the artifact area and the patient's breathing signal has been saved, if yes, execute s106, if no, execute s104;

s104. Automatically detect the position of the skin line in the image currently collected by the ultrasound probe, and move the ultrasound probe in a direction close to the skin according to the position of the skin line until the image collected by the ultrasound probe has fewer or no artifacts When the ultrasound probe moves to the position where the distance between the ultrasound probe and the skin is 0-5cm, stop moving the ultrasound probe, and set the position of the ultrasound probe at this moment as the reference position, and record the spatial position of the ultrasound probe at the same time. Acquiring several groups of image sequences of several consecutive breathing cycles at the reference position, and selecting a group of image sequences of one of the breathing cycles as a reference image sequence;

S105. While collecting the reference image sequence, collect the respiratory signal of the patient, introduce the respiratory signal into the reference image sequence, and save the reference image sequence into which the respiratory signal has been introduced;

s106. Move the ultrasound probe from the reference position to the treatment position according to the spatial position recorded in s101, and collect the current treatment image;

s107. Collecting the patient's breathing signal while collecting the current treatment image, and introducing the breathing signal into the current treatment image;

s108. Load the reference image sequence that has introduced the respiratory signal, and perform respiratory signal registration on the current treatment image that has introduced the respiratory signal and a reference image in the reference image sequence that has introduced the respiratory signal, and The phase of the reference image is the same as that of the current treatment image, and the reference image after the physiological signal registration is completed is output in real time;

s109. According to the different spatial positions of the ultrasonic probe when collecting the reference image and the treatment image, perform spatial registration on the reference image that has been output in real time in s108 and complete the physiological signal registration and the current treatment image, and perform spatial registration on the space-registered Real-time output of reference images;

s110. Fusing the reference image of the completed physiological signal registration and spatial registration output in s109 in real time with the current treatment image in real time, and outputting the fused image in real time;

s111. Determine whether the artifacts in the treatment image collected by the ultrasonic probe are significantly reduced at the next moment, if yes, execute s113, if not, execute s112;

s112. Collect the treatment image at the next moment, collect the patient's respiratory signal at the same time, and introduce the respiratory signal into the treatment image, and then execute s108;

s113. Real-time output of treatment images collected by the ultrasound probe.

This embodiment also provides a device for reducing artifacts in images in real time. As shown in FIG. 2 , the device includes: a motion unit, a physiological signal acquisition unit, an image registration unit, a control unit, an image fusion unit, and a display unit.

Motion unit for moving the ultrasound probe.

The physiological signal acquisition unit is used to collect the physiological signals of the patient in real time, and is used to receive the reference image collected by the ultrasonic probe at the reference position and the current treatment image collected at the treatment position, and then introduce the collected physiological signals of the patient into the ultrasonic probe In the reference image sequence acquired at the reference position and the current treatment image acquired at the treatment position, then the reference image sequence into which the patient's physiological signal has been introduced and the current treatment image are output to the image registration unit in real time, which One of the sequence of reference images into which the patient's physiological signal is introduced is registered with the current treatment image into which the patient's physiological signal has been introduced. Wherein, the reference image collected by the ultrasonic probe is a plurality of time-continuous reference images, and the multiple time-continuous reference images are a plurality of image sequences of multiple consistent or substantially consistent continuous physiological signal periods collected by the ultrasonic probe Any set of image sequences in , this image sequence is the reference image sequence.

In this embodiment, the physiological signal acquisition unit includes: a physiological signal sensor, an amplifier, an analog-to-digital converter, and a single-chip microcomputer. The physiological signal sensor is used to detect and collect physiological signals in real time, and then transmit them to the amplifier; the amplifier is used to amplify the collected physiological signals, and then output them to the analog-to-digital converter; the analog-to-digital The converter is used to convert the amplified physiological signal into a digital signal, and then output it to the single-chip microcomputer; the single-chip microcomputer is used to transmit the digital signal to the computer. The computer introduces the physiological signal converted into a digital signal into a sequence of reference images or a current treatment image.

The physiological signal acquisition unit is an existing product, wherein the physiological signal sensor includes a respiratory signal sensor and a pulse signal sensor, and the two sensors can be selected from any one that can stably detect the two signals. For example, the respiratory signal sensor can use JKY/314959 type, the pulse signal sensor can use DT&SDT type MEAS piezoelectric film sensor.

The image registration unit is configured to receive the reference image collected by the ultrasound probe at the reference position and the treatment image collected at the treatment position, register the reference image collected by the ultrasound probe with the treatment image, and real-time register the reference image after registration. output to the image fusion unit.

Wherein, the image registration unit includes a physiological signal registration module and a spatial registration module.

The physiological signal registration module is used to receive the reference image sequence of the introduced patient's physiological signal and the current treatment image of the introduced patient's physiological signal, and combine the introduced current treatment image of the patient's physiological signal with the introduced patient's physiological signal Physiological signal registration is performed on a reference image in the reference image sequence of the physiological signal, and the phase of the reference image is the same as that of the current treatment image, and then the reference image after the physiological signal registration is completed is output to the spatial registration module in real time ,

The spatial registration module is used to receive the reference image output by the physiological signal registration module after the physiological signal registration is completed, and according to the different spatial positions of the ultrasonic probe transmitted by the control unit when acquiring the reference image sequence and the current treatment image performing spatial registration on the reference image after the physiological signal registration is completed and the current treatment image, and outputting the reference image after the spatial registration to the image fusion unit in real time;

Alternatively, the spatial registration module is used to receive different spatial position signals of the ultrasonic probe transmitted by the control unit when acquiring the reference image sequence and the current treatment image, and accordingly align the current treatment image and all the images in the reference image sequence in a spatial alignment. Registration, and then real-time output of the reference image sequence after spatial registration is completed to the physiological signal registration module;

The physiological signal registration module is used to receive the spatially registered reference image sequence output by the spatial registration module, and combine the current treatment image of the introduced patient's physiological signal and the introduced patient's physiological signal Physiological signal registration is performed on a reference image in the reference image sequence, and the phase of the reference image is the same as that of the current treatment image, and the registered reference image is output to the image fusion unit in real time.

Specifically, the spatial registration module is used to convert the coordinate difference between the spatial position of the ultrasonic probe when acquiring the reference image and the spatial position when acquiring the current treatment image into the pixel difference between the reference image and the current treatment image, according to The pixel difference completes the spatial registration of the current treatment image and the reference image; the image fusion unit is used to select all of the registered reference image or only the part containing the treatment target area and the current treatment image Perform real-time fusion.

The control unit is used to instruct the motion unit to move the ultrasonic probe according to the information input from the outside; it is also used to record the spatial position of the ultrasonic probe when the ultrasonic probe is in the treatment position, record the spatial position of the ultrasonic probe when the ultrasonic probe is in the reference position, and Outputting the recorded spatial position signals of the ultrasonic probes when acquiring the reference image sequence and the current treatment image to the spatial registration module.

The image fusion unit is configured to receive the registered reference image output by the image registration unit, fuse the registered reference image and the treatment image in real time, and output the fused image to the display unit in real time.

The display unit is used to receive and display the image output by the image fusion unit.

Example 2:

According to the patient's lesion being affected by respiration and/or heartbeat, when the lesion is greatly affected by heartbeat, the one physiological signal cycle is one heartbeat signal cycle. In this embodiment, the patient's lesions are greatly affected by the heartbeat. Since the frequency of the human body's heartbeat is the same as the pulse, the pulse cycle can also be equivalent to the heartbeat cycle. Therefore, several groups of image sequences of several continuous pulse signal cycles are collected. One is used as a reference image sequence. As shown in Figure 3, the specific steps of the method for reducing artifacts in an image in real time are as follows:

s201. Move the ultrasound probe to the treatment position and collect images of the current lesion, and record the spatial position of the ultrasound probe at this time;

s202. Judging whether there are many artifacts in the treatment image collected by the current ultrasonic probe, if yes, execute s103, if not, execute s113;

s203. Detect whether the reference image sequence containing the artifact region and the pulse signal of the patient has been saved, if yes, execute s106, if no, execute s104;

s204. Automatically detect the position of the skin line in the image currently collected by the ultrasound probe, and move the ultrasound probe in a direction close to the skin according to the position of the skin line until the image collected by the ultrasound probe has fewer or no artifacts When the ultrasound probe moves to the position where the distance between the ultrasound probe and the skin is 0-5cm, stop moving the ultrasound probe, and set the position of the ultrasound probe at this moment as the reference position, and record the spatial position of the ultrasound probe at the same time. Acquisition of several groups of image sequences of several consecutive pulse cycles at the reference position, and selecting a group of image sequences of one of the pulse cycles as a reference image sequence;

s205. While acquiring the reference image sequence, acquire the pulse signal of the patient, and introduce the pulse signal into the reference image sequence, and keep the reference image sequence into which the pulse signal has been introduced;

s206. Move the ultrasound probe from the reference position to the treatment position according to the spatial position recorded in s101, and collect the current treatment image;

s207. Collecting the pulse signal of the patient while collecting the current treatment image, and introducing the pulse signal into the current treatment image;

s208. Load the reference image sequence that has introduced the respiratory signal, and combine the current treatment image that has introduced the pulse signal with all the reference image sequences in the reference image sequence according to the different spatial positions of the ultrasonic probe when acquiring the reference image and the treatment image. The image is spatially registered, and the reference image sequence after spatial registration is output in real time;

s209. Perform pulse signal registration on the current treatment image into which the pulse signal has been introduced and a reference image in the reference image sequence output in real time in s108, and the phase of the reference image is the same as that of the current treatment image, and Real-time output of reference images after physiological signal registration;

s210. Fusing the reference image of the completed physiological signal registration and spatial registration output in s109 in real time with the current treatment image in real time, and outputting the fused image in real time;

s211. Judging whether the artifacts in the treatment image collected by the ultrasonic probe are significantly reduced at the next moment, if yes, execute s113, if not, execute s112;

s212. collect the treatment image at the next moment, and collect the pulse signal of the patient at the same time, and introduce the pulse signal into the treatment image, and then execute s109;

s213. Real-time output of treatment images collected by the ultrasound probe.

The apparatus for reducing artifacts in an image in real time proposed in this embodiment is the same as that in Embodiment 1, and will not be repeated here.

Example 3:

According to the influence of respiration and/or heartbeat on the focus of the patient, when the focus is affected by respiration and heartbeat at the same time, and the degree of influence is relatively large, the time between the respiration signal period and the heartbeat signal period is used for the one physiological signal period. longer period. In this embodiment, the patient's lesions are affected by breathing and heartbeat at the same time, and the degree of influence is relatively large. Since the time of a breathing signal cycle is longer than that of a heartbeat signal cycle, a breathing signal cycle is used as a physiological signal cycle. , that is, to collect several groups of image sequences of several consecutive respiratory signal periods, and select one of them as a reference image sequence.

The method for reducing artifacts in images in real time and the device for reducing artifacts in images in real time proposed in this embodiment are the same as those in Embodiment 1, and will not be repeated here.

It can be understood that, the above embodiments are only exemplary embodiments adopted for illustrating the principle of the present invention, but the present invention is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also regarded as the protection scope of the present invention.

Claims (11)

1. reduce a method for artifact in image in real time, comprise the steps:

1) reference picture is gathered: the ultrasonic probe being in treatment position is moved to the position obtaining reference picture, and the image being gathered focus in the position of described reference picture by ultrasonic probe is as with reference to image, the position of described reference picture is the less or artifact-free a certain position of part artifact corresponding with therapy area in the image that ultrasonic probe can be made to gather, the locus of ultrasonic probe is recorded when ultrasonic probe is in treatment position, the locus of ultrasonic probe is recorded when ultrasonic probe is in the position of reference picture, the reference picture gathered is the reference picture of several Time Continuous, the reference picture of these several Time Continuous forms reference image sequence, while the described reference image sequence of collection, gather the physiological signal of patient, and described physiological signal is introduced in described reference image sequence, make a phase place in all corresponding physiological signal cycle of each the width reference picture in reference image sequence,

2) treatment image is gathered: ultrasonic probe is moved back to described treatment position from the position of described reference picture, and gather focus Current therapeutic image by ultrasonic probe, while collection treatment image, gather the physiological signal of patient, and described physiological signal is introduced Current therapeutic image, make a phase place in the Current therapeutic image corresponding physiological signal cycle;

3) registration of image and fusion: the treatment image collected and described reference picture are carried out registration and fusion, and export the image after merging, this image is actual therapeutic image, wherein, the treatment image collected and described reference picture is carried out registration and fusion comprises:

31) by physiological signal registration Algorithm, the Current therapeutic image and the width reference picture introduced in the reference image sequence of physiological signal of introducing physiological signal are carried out physiological signal registration, and this reference picture is identical with the phase place of Current therapeutic image, and the reference picture exported in real time after physiological signal registration, again according to the different spatial of ultrasonic probe when gathering reference image sequence and Current therapeutic image, the reference picture after physiological signal registration is completed and Current therapeutic image carries out spatial registration by described, and exported the reference picture after spatial registration,

Or, according to the different spatial of ultrasonic probe when gathering reference image sequence and Current therapeutic image, the Current therapeutic image and all reference pictures introduced in the reference image sequence of physiological signal of introducing physiological signal are carried out spatial registration, and exported the reference image sequence after spatial registration, the Current therapeutic image having introduced physiological signal by physiological signal registration Algorithm by described again and introduced physiological signal and the width reference picture completed in the reference image sequence after spatial registration carries out physiological signal registration, and this reference picture is identical with Current therapeutic image phase, and the reference picture exported after physiological signal registration,

32) reference picture and described Current therapeutic image that complete physiological signal registration and spatial registration are carried out real time fusion, and the image after merging is exported in real time.

2. method according to claim 1, it is characterized in that, step 1) in, first judge whether there is more artifact in the image that ultrasonic probe gathers at described treatment position, if artifact is more, then move ultrasonic probe from treatment position along the direction close to skin according to the position of skin line in the image of ultrasonic probe collection, until it is the position of 0 ~ 5cm that described ultrasonic probe moves to the distance of skin, namely ultrasonic probe moves to the position of reference picture, stop mobile ultrasonic probe, at the reference picture of the station acquisition focus of described reference picture.

3. method according to claim 1, it is characterized in that, step 1) in, the process gathering described reference image sequence is as follows: the multiple series of images sequence gathering multiple continuous physiological signal cycle, and corresponding one group of image sequence of each physiological signal cycle, and whether inspection is consistent at each group of image sequence of each physiological signal cycle collection, if unanimously, then one group of image sequence in one of them physiological signal cycle optional is as reference image sequence; If inconsistent, then continue the image sequence gathering the next physiological signal cycle, and its image sequence with the last physiological signal cycle is compared, until the multiple series of images sequence in the multiple continuous physiological signal cycle collected is consistent, then select in the multiple series of images sequence in described multiple continuous physiological signal cycle any one group as with reference to image sequence.

4. method according to claim 3, is characterized in that,

Step 1) in, in described multiple continuous physiological signal cycle, each physiological signal cycle all comprises several different phase places, according to several the different phase places in physiological signal cycle when gathering reference image sequence corresponding to it, namely one in the described physiological signal cycle corresponding from it respectively by the every width reference picture in described reference image sequence different phase place is associated is that physiological signal is introduced reference image sequence;

Step 2) in, according to the phase place that in physiological signal cycle during collection treatment image corresponding to it is different, namely the phase place that described Current therapeutic image is different from the described physiological signal cycle corresponding to it be associated is that physiological signal is introduced Current therapeutic image.

5. method according to claim 4, it is characterized in that, step 3) in, reference picture in the Current therapeutic image collected and reference image sequence is carried out registration and fusion, and exports the image after merging in real time, then continue the treatment image gathering subsequent time, reference picture in itself and reference image sequence is carried out registration and fusion, and export the image after merging in real time, so circulate, namely obtain the actual therapeutic image exported continuously.

6. method according to claim 1, it is characterized in that, step 31) in, the method that described Current therapeutic image and reference picture carry out spatial registration is: locus when ultrasonic probe being gathered reference picture is converted to the pixel value difference of described reference picture and Current therapeutic image with the coordinate difference of locus when gathering Current therapeutic image, completes the spatial registration of Current therapeutic image and reference picture according to described pixel value difference;

Step 32) in, when merging with treatment figure with reference to image, the part chosen whole in described reference picture or only comprise therapy area carries out real time fusion with described Current therapeutic image, and fusion method adopts average gray value method or pixel grey scale area method.

7. method according to claim 6, is characterized in that, step 31) in, spatial registration method is specially:

Locus setting coordinate when ultrasonic probe being gathered described Current therapeutic image is P1 (x1, y1, z1), and locus setting coordinate when ultrasonic probe being gathered described reference picture is P2 (x2, y2, z2);

Assuming that ultrasonic probe moves in yz plane, then the coordinate difference of x1=x2, P1 point and P2 point is dy=y1-y2, dz=z1-z2;

Assuming that in Current therapeutic image and reference picture, the size of each pixel is m × n, when then Current therapeutic image and reference picture being carried out spatial registration, reference picture is made to move dy/m pixel in y-direction, make reference picture move dz/n pixel in a z-direction, just complete the spatial registration of Current therapeutic image and reference picture;

Step 32) in, described fusion method specifically comprises: choose the part only comprising therapy area in described reference picture when carrying out real time fusion with described Current therapeutic image, if certain in described reference picture a bit exceeds the scope chosen, then without the need to merging, directly export the gray-scale value of gray-scale value as fused image of corresponding point in Current therapeutic image.

8. method according to claim 1, is characterized in that, described physiological signal registration Algorithm comprises Signal Pretreatment algorithm and signal registration algorithm, and described Signal Pretreatment algorithm is by Real-time Collection and the physiological signal processed is normalized; Described signal registration algorithm adopts dynamic time convolution algorithm.

9. the method according to any one of claim 1-8, is characterized in that, when the impact that described focus is breathed is larger, a described physiological signal cycle is a breath signal cycle; When described focus is subject to the impact of heartbeat larger, a described physiological signal cycle is a heartbeat signal cycle; When described focus is breathed and the impact of heartbeat simultaneously, and when effect is all larger, a described physiological signal cycle is a breath signal cycle.

10. reduce a device for artifact in image in real time, it is characterized in that, this device comprises: image registration unit, image co-registration unit and display unit,

Image registration unit, for receiving the reference picture that ultrasonic probe gathers in reference position and the treatment image gathered at treatment position, and carries out registration by the reference picture of ultrasonic probe collection and treatment image, and is exported in real time by the reference picture after registration; Wherein, described reference position is that in the image that gathers of ultrasonic probe, the part artifact corresponding with therapy area is less or without the position at ultrasonic probe place during artifact;

Image co-registration unit, for receiving the reference picture after registration that image registration unit exports, carries out real time fusion by the reference picture after described registration and treatment image, and is exported in real time by the image after merging;

Display unit, for receive and show image co-registration unit export image;

Physiological signal collection unit is also included in this device, the reference picture that described ultrasonic probe gathers is the reference picture of several Time Continuous, the reference picture of these several Time Continuous is any one group of image sequence in the multiple series of images sequence in multiple continuous physiological signal cycles unanimously that ultrasonic probe gathers, this image sequence is reference image sequence

Described physiological signal collection unit is used for the physiological signal of Real-time Collection patient, and for receiving the reference picture that ultrasonic probe gathers in reference position and the Current therapeutic image gathered at treatment position, the physiological signal of the patient it gathered again is introduced in reference image sequence that ultrasonic probe gathers in reference position and the Current therapeutic image that treatment position gathers respectively, then the reference image sequence and Current therapeutic image of introducing the physiological signal of patient is exported to image registration unit in real time, by it, described Current therapeutic image having introduced the width in the reference image sequence of the physiological signal of patient and the physiological signal of having introduced patient is carried out registration, then image co-registration unit is exported in real time to by completing the reference picture after registration,

This device also includes moving cell and control module,

Moving cell, for mobile ultrasonic probe;

Control module, the information for inputting according to outside is carried out instruction moving cell and is moved ultrasonic probe;

Described image registration unit comprises physiological signal registration module and spatial registration module,

Described control module is also for recording the locus of ultrasonic probe when ultrasonic probe is in treatment position, the locus of ultrasonic probe is recorded when ultrasonic probe is in reference position, and export the locus signal that ultrasonic probe when recorded collection reference image sequence and Current therapeutic image is residing respectively to spatial registration module

Described physiological signal registration module is for receiving the reference image sequence of the physiological signal introducing patient and having introduced the Current therapeutic image of physiological signal of patient, and the width reference picture in the reference image sequence of the described Current therapeutic image having introduced the physiological signal of patient and the physiological signal having introduced patient is carried out physiological signal registration, and this reference picture is identical with the phase place of described Current therapeutic image, export the reference picture after physiological signal registration more in real time to spatial registration module

The reference picture completed after physiological signal registration that described spatial registration module exports for receiving described physiological signal registration module, and according to the different spatial of ultrasonic probe when gathering reference image sequence and Current therapeutic image that control module transmits, complete the reference picture after physiological signal registration and Current therapeutic image carries out spatial registration by described, and export image co-registration unit in real time to by completing the reference picture after spatial registration;

Or, described spatial registration module is used for the different spatial signal of ultrasonic probe when gathering reference image sequence and Current therapeutic image that reception control unit transmits, and accordingly all images in Current therapeutic image and reference image sequence are carried out spatial registration, then the reference image sequence exported in real time after spatial registration is to physiological signal registration module;

The reference image sequence completed after spatial registration that described physiological signal registration module exports for receiving spatial registration module, and the Current therapeutic image having introduced the physiological signal of patient by described and the described width reference picture introduced in the reference image sequence of the physiological signal of patient carry out physiological signal registration, and this reference picture is identical with the phase place of described Current therapeutic image, and export the reference picture after registration to image co-registration unit in real time.

11. devices according to claim 10, it is characterized in that, the coordinate difference of locus when described spatial registration module is used for locus when ultrasonic probe being gathered reference picture and gathers Current therapeutic image is converted to the pixel value difference of described reference picture and Current therapeutic image, completes the spatial registration of Current therapeutic image and reference picture according to described pixel value difference; Described image co-registration unit carries out real time fusion for the whole of the reference picture after choosing described registration or the part that only comprises therapy area with described Current therapeutic image.