CN105005974A - Global repair based method and system for assignment for vacant voxels in ultrasound volume data - Google Patents

Abstract

The invention discloses a global repair based method and system for assignment for vacant voxels in ultrasound volume data. The method comprises the steps of traversing the ultrasound volume data, separating vacant areas comprising non-assigned voxels, and extracting borders of the vacant areas; defining a data item and a smooth item, and calculating repairing weights of the non-assigned voxels; defining a cube area with the voxel with the largest repair weight as the center as an earliest repaired area, and seeking in the whole ultrasound volume data the area most similar to the earliest repaired area; repairing the non-assigned voxels in the earliest repaired area with the voxel gray value in the most similar area; and updating the vacant areas in the ultrasound volume data. Through adoption of the method, non-assigned voxels in the ultrasound volume data can be rapidly assigned accurately, so that high precision reconstruction of the ultrasound volume data can be realized.

Description

Based on ultrasonic volume data vacancy voxel assignment method and the system of global fix-up

Technical field

The present invention relates to medicine technology field, be specifically related to a kind of ultrasonic volume data vacancy voxel assignment method based on global fix-up and system.

Background technology

Ultrasonic imaging utilizes ultrasonic irradiation human body, by receiving and process the echo being loaded with tissue characteristic information, obtain the Method and Technology of the visual picture of tissue character and structure, is called 3 of modern medicine large iconographies with CT, MRI.Compared with CT, MRI, ultrasonic imaging have acquisition time short, need not intravenous injection contrast preparation, without ionising radiation, economical convenient, can the advantage such as real time imagery, become clinical requisite Diagnosis and Treat equipment.But when doctor thinks to understand anatomical feature more accurately, 2 traditional dimension imagings just seem and can not meet the demands.Tie up compared with ultrasonoscopy with traditional 2,3 dimensions are ultrasonic has image intuitive display, accurately measure the clear superiorities such as structural parameters, accurately location pathological tissues, become the important supplementary means of 2 dimension ultrasonic techniques.From clinical practice angle, Freehand scanning more meets doctor's custom and operating room environment, and Freehand 3 ties up ultrasonic having a wide range of applications.3 d reconstruction algorithm realizes Freehand 3 to tie up ultrasonic key, and therefore the 3 d reconstruction algorithm of Freehand ultrasonoscopy has important researching value.But there is the defect of vacancy voxel repair efficiency difference in current ultrasonoscopy three-dimensional rebuilding method.

Summary of the invention

Embodiment of the present invention technical matters to be solved is, provides a kind of ultrasonic volume data vacancy voxel assignment method based on global fix-up and system, can repair the vacancy voxel in ultrasonic volume data accurately.

For solving the problems of the technologies described above, embodiments providing a kind of ultrasonic volume data vacancy voxel assignment method based on global fix-up, comprising:

Travel through ultrasonic volume data, be separated the area of absence comprising the voxel not having assignment, and extract the border of area of absence;

Definition data item and level and smooth item, calculate the repairing weight not having the voxel of assignment;

Definition take the cubical area of repairing centered by the maximum voxel of weight as repairing area at first, the region that searching is the most similar to repairing area at first in whole ultrasonic volume data;

The voxel not having assignment in repairing area is at first repaired with the voxel gray values in the most similar region;

Upgrade the area of absence in ultrasonic volume data.

In other schemes of the present invention, the principle of the individual voxel of assignment arbitrarily around the voxel of assignment is not had to extract area of absence border according to ultrasonic volume data one.

In other schemes of the present invention, the number of the voxel of assignment in a scope around the voxel that data item record one does not have an assignment.

In other schemes of the present invention, level and smooth item records the intensity of variation that does not have voxel gray values in a scope around assignment voxel.

In other schemes of the present invention, this scope is 9 × 9 × 9.

In other schemes of the present invention, the most similar region be two all corresponding voxel intensity value differences in region with minimum.

The embodiment of the present invention additionally provides a kind of ultrasonic volume data vacancy voxel assignment system based on global fix-up, it is characterized in that, comprising:

Area of absence extraction module, it travels through ultrasonic volume data, is separated the area of absence comprising the voxel not having assignment, and extracts the border of area of absence;

Repair weight computation module, its definition data item and level and smooth item, calculate the repairing weight not having the voxel of assignment;

Most similar area finds module, defines to repair cubical area centered by the maximum voxel of weight for repairing area at first, in whole ultrasonic volume data, finds the region the most similar to repairing area at first;

Area of absence repairs module, and it repairs the voxel not having assignment in repairing area at first with the voxel gray values in the most similar region;

Area of absence update module, it upgrades the area of absence in ultrasonic volume data.

The present invention can the body art assignment for not having assignment in ultrasonic volume data of fast accurate, and the high precision realizing ultrasonic volume data is rebuild.

Accompanying drawing explanation

Fig. 1 is the schematic flow sheet of the ultrasonic volume data vacancy voxel assignment method based on global fix-up of the embodiment of the present invention;

Fig. 2 is the most similar area schematic diagram of searching proposed by the invention;

Fig. 3 is the structural representation of the ultrasonic volume data vacancy voxel assignment system based on global fix-up of the embodiment of the present invention.

Embodiment

Below in conjunction with the drawings and specific embodiments, the present invention is described in further detail, but not as a limitation of the invention.

Fig. 1 is the schematic flow sheet of the ultrasonic volume data vacancy voxel assignment method based on global fix-up of the embodiment of the present invention, and concrete steps comprise:

Step S1,

Travel through ultrasonic volume data, be separated the area of absence comprising the voxel not having assignment, and extract the border of area of absence.

Each voxel in the ultrasonic volume data of order traversal, when a voxel does not have assignment time, judges voxels all in this voxel surrounding adjacent regions, if there is the voxel of assignment, so this does not have the voxel of assignment to be the borderline voxel of area of absence; If voxels all in surrounding adjacent regions does not all have assignment, so this does not have the voxel of assignment to be the voxel of area of absence inside.

Step S2,

Definition data item and level and smooth item, calculate the repairing weight not having the voxel of assignment.

Definition p is the borderline voxel not having an assignment of area of absence in ultrasonic volume data, definition Ψ _pfor the cube of 9 × 9 × 9 sizes centered by the voxel p not having assignment, definition C (p) is for treating cube Ψ _pin the number of the voxel of assignment.Data item C (p) can be obtained by the number of the voxel of assignment and the ratio of whole cube block size:

$C\left(p\right)=\frac{{\mathrm{\Σ}}_{q\∈{\mathrm{\Ψ}}_{\mathrm{\ρ}}\∩\left(I-\mathrm{\Ω}\right)}C\left(q\right)}{\left|{\mathrm{\Ψ}}_p\right|}$

Definition D (p) is cube Ψ _plevel and smooth item, α is normalized factor, n _pfor the vector of unit length orthogonal with not having the voxel p of assignment, ⊥ represents that orthogonal operation accords with, and level and smooth item D (p) is:

$D\left(p\right)=\frac{\left|\▿I_p^{\⊥}\·n_p\right|}{\mathrm{\α}}$

Cube Ψ _prepairing weight P (p) of central point p is:

P(p)＝C(p)D(p)

Step S3,

Definition take the cubical area of repairing centered by the maximum voxel of weight as repairing area at first, the region that searching is the most similar to repairing area at first in whole ultrasonic volume data.

Define repairing area Ψ at first _pto repair the cube of 9 × 9 × 9 sizes centered by the maximum voxel p not having assignment of weight, travel through whole ultrasonic volume data, find and Ψ _pthe most similar region.Defining the most similar is that in region, correspondence position voxel intensity difference absolute value sum is minimum, and most similar area is:

Wherein, expression and at first repairing area Ψ _pthe non-Ψ that size is identical _pregion, d (Ψ _a, Ψ _b) represent two region Ψ _aand Ψ _bbetween correspondence position voxel intensity difference absolute value sum.

Step S4,

The voxel not having assignment in repairing area is at first repaired with the voxel gray values in the most similar region.

According to the gray-scale value of the voxel of the assignment found in the most similar area that obtains, for there is no the voxel assignment of assignment in patch area at first.

Step S5,

Upgrade the area of absence in ultrasonic volume data.

After repairing according to the voxel gray values in the most similar region and there is no the voxel of assignment in repairing area at first, in ultrasonic volume data, area of absence changes, again need detect the area of absence in ultrasonic volume data and border thereof, rebuild the repairing weight calculating and do not have the voxel of assignment.

Fig. 3 is the structural representation of the ultrasonic volume data vacancy voxel assignment system based on global fix-up of the embodiment of the present invention.As shown in Figure 3, comprise area of absence extraction module based on the ultrasonic volume data vacancy voxel assignment system of global fix-up, repair weight computation module, most similar area finds module, area of absence repairs module, area of absence update module.

1, area of absence extraction module

Travel through ultrasonic volume data, be separated the area of absence comprising the voxel not having assignment, and extract the border of area of absence.

Each voxel in the ultrasonic volume data of order traversal, when a voxel does not have assignment time, judges voxels all in this voxel surrounding adjacent regions, if there is the voxel of assignment, so this does not have the voxel of assignment to be the borderline voxel of area of absence; If voxels all in surrounding adjacent regions does not all have assignment, so this does not have the voxel of assignment to be the voxel of area of absence inside.

2, weight computation module is repaired

Definition data item and level and smooth item, describe the repairing weight not having the voxel of assignment.

Definition p is the borderline voxel not having an assignment of area of absence in ultrasonic volume data, definition Ψ _pfor the cube of 9 × 9 × 9 sizes centered by the voxel p not having assignment, definition C (p) is for treating cube Ψ _pin the number of the voxel of assignment.Data item C (p) can be obtained by the number of the voxel of assignment and the ratio of whole cube block size:

$C\left(p\right)=\frac{{\mathrm{\Σ}}_{q\∈{\mathrm{\Ψ}}_{\mathrm{\ρ}}\∩\left(I-\mathrm{\Ω}\right)}C\left(q\right)}{\left|{\mathrm{\Ψ}}_p\right|}$

Definition D (p) is cube Ψ _plevel and smooth item, α is normalized factor, n _pfor the vector of unit length orthogonal with not having the voxel p of assignment, ⊥ represents that orthogonal operation accords with, and level and smooth item D (p) is:

$D\left(p\right)=\frac{\left|\▿I_p^{\⊥}\·n_p\right|}{\mathrm{\α}}$

Cube Ψ _prepairing weight P (p) of central point p is:

P(p)＝C(p)D(p)

3, most similar area finds module

Definition take the cubical area of repairing centered by the maximum voxel of weight as repairing area at first, the region that searching is the most similar to repairing area at first in whole ultrasonic volume data.

Define repairing area Ψ at first _pto repair the cube of 9 × 9 × 9 sizes centered by the maximum voxel p not having assignment of weight, travel through whole ultrasonic volume data, find and Ψ _pthe most similar region.Defining the most similar is that in region, correspondence position voxel intensity difference absolute value sum is minimum, and most similar area is:

Wherein, expression and at first repairing area Ψ _pthe non-Ψ that size is identical _pregion, d (Ψ _a, Ψ _b) represent two region Ψ _aand Ψ _bbetween correspondence position voxel intensity difference absolute value sum.

4, area of absence repairs module

The voxel not having assignment in repairing area is at first repaired with the voxel gray values in the most similar region.

According to the gray-scale value of the voxel of the assignment found in the most similar area that obtains, for there is no the voxel assignment of assignment in patch area at first.

5, area of absence update module

Upgrade the area of absence in ultrasonic volume data.

After repairing according to the voxel gray values in the most similar region and there is no the voxel of assignment in repairing area at first, in ultrasonic volume data, area of absence changes, again need detect the area of absence in ultrasonic volume data and border thereof, rebuild the repairing weight calculating and do not have the voxel of assignment.

Utilize the present invention, can the ultrasonic volume data of reconstruction of fast accurate, for clinical foci diagnosis and treatment provide theoretical direction.

Certainly, the above is the preferred embodiment of the present invention.For convenience of description, employ the sequence number such as step S1, S2, but it will be recognized that these steps itself can also comprise other processes, can also have other steps between these steps, this is also within protection scope of the present invention.It should be pointed out that for those skilled in the art, under the premise without departing from the principles of the invention, can also make some improvements and modifications, these improvements and modifications are also considered as protection scope of the present invention.

Claims (10)

1., based on a ultrasonic volume data vacancy voxel assignment method for global fix-up, it is characterized in that, comprising:

Travel through ultrasonic volume data, be separated the area of absence comprising the voxel not having assignment, and extract the border of area of absence;

Definition data item and level and smooth item, calculate the repairing weight not having the voxel of assignment;

Definition take the cubical area of repairing centered by the maximum voxel of weight as repairing area at first, the region that searching is the most similar to repairing area at first in whole ultrasonic volume data;

The voxel not having assignment in repairing area is at first repaired with the voxel gray values in the most similar region;

Upgrade the area of absence in ultrasonic volume data.

2. the ultrasonic volume data vacancy voxel assignment method based on global fix-up according to claim 1, is characterized in that, does not have the principle of the individual voxel of assignment arbitrarily around the voxel of assignment to extract area of absence border according to ultrasonic volume data one.

3. the ultrasonic volume data vacancy voxel assignment method based on global fix-up according to claim 1, is characterized in that, the number of the voxel of assignment in a scope around the voxel that data item record one does not have an assignment.

4. the ultrasonic volume data vacancy voxel assignment method based on global fix-up according to claim 1, it is characterized in that, level and smooth item records the intensity of variation that does not have voxel gray values in a scope around assignment voxel.

5. the ultrasonic volume data vacancy voxel assignment method based on global fix-up according to claim 3 or 4, it is characterized in that, this scope is 9 × 9 × 9.

6. the ultrasonic volume data vacancy voxel assignment method based on global fix-up according to claim 1, is characterized in that, the most similar region be two all corresponding voxel intensity value differences in region with minimum.

7., based on a ultrasonic volume data vacancy voxel assignment system for global fix-up, it is characterized in that, comprising:

Area of absence extraction module, it travels through ultrasonic volume data, is separated the area of absence comprising the voxel not having assignment, and extracts the border of area of absence;

Repair weight computation module, its definition data item and level and smooth item, calculate the repairing weight not having the voxel of assignment;

Most similar area finds module, defines to repair cubical area centered by the maximum voxel of weight for repairing area at first, in whole ultrasonic volume data, finds the region the most similar to repairing area at first;

Area of absence repairs module, and it repairs the voxel not having assignment in repairing area at first with the voxel gray values in the most similar region;

Area of absence update module, it upgrades the area of absence in ultrasonic volume data.

8. the ultrasonic volume data vacancy voxel assignment system based on global fix-up according to claim 7, is characterized in that, does not have the principle of the individual voxel of assignment arbitrarily around the voxel of assignment to extract area of absence border according to ultrasonic volume data one.

9. the ultrasonic volume data vacancy voxel assignment system based on global fix-up according to claim 7, is characterized in that, the number of the voxel of assignment in a scope around the voxel that data item record one does not have an assignment.

10. the ultrasonic volume data vacancy voxel assignment system based on global fix-up according to claim 7, it is characterized in that, level and smooth item records the intensity of variation that does not have voxel gray values in a scope around assignment voxel.