Ct image correction

Patent metadata

Field	Value
Publication number	US-2016143604-A1
Application number	US-201514952864-A
Country	US
Kind code	A1
Filing date	Nov 25, 2015
Priority date	Nov 26, 2014
Publication date	May 26, 2016
Grant date	—

Abstract

A method and system for CT image correction are provided. Contour data of a scanned subject can be obtained, and a shape image of the scanned subject can be reconstructed according to the contour data, wherein the contour data of the scanned subject can be obtained by scanning the scanned subject through a piece of visual equipment. Original CT projection data of the scanned subject can be obtained, and a CT image can be reconstructed according to the original CT projection data. For determining a supervision field image, image matching can be performed between the shape image and the CT image of the scanned subject. Supervision field projection data can be obtained, and the supervision field projection data can be used to correct the CT image.

First claim

1 . A method for CT image correction, the method comprising:
obtaining contour data of a scanned subject, and reconstructing a shape image of the scanned subject according to the contour data, wherein the contour data of the scanned subject is obtained by scanning the scanned subject through a piece of visual equipment; obtaining original CT projection data of the scanned subject, and reconstructing a CT image according to the original CT projection data; performing image matching between the shape image and the CT image of the scanned subject for determining a supervision field image; and obtaining supervision field projection data, and using the supervision projection data to correct the CT image.

2 . The method of claim 1 , wherein when the visual equipment is mounted on a gantry of a CT device, said reconstructing the shape image of the scanned subject according to the contour data comprises:
obtaining scan data by scanning the scanned subject with the visual equipment; reconstructing an original visual image of the scanned subject according to the scan data, wherein the reconstructed original visual image of the scanned subject comprises an image of an appendage blocking the scanned subject; and obtaining the shape image of the scanned subject by removing the image of the appendage from the original visual image of the scanned subject.

3 . The method of claim 1 , wherein when the visual equipment is mounted on the gantry of the CT device, said performing the image matching on the shape image and the CT image of the scanned subject comprises:
obtaining a relative position relationship between the shape image and the CT image according to a consistency between the shape image and the CT image of the scanned subject in space; and performing the image matching on the shape image and the CT image of the scanned subject according to the relative position relationship.

4 . The method of claim 1 , further comprising:
placing a positioning assisting device on the scanned subject, wherein the positioning assisting device is used to assist the image matching of the shape image and the CT image.

5 . The method of claim 4 , wherein when the visual equipment is not mounted on the gantry of the CT device, and wherein said performing an image matching between the shape image and the CT image of the scanned subject comprises:
providing the shape image and the CT image of the scanned subject, respectively; performing image segmentation on the shape image for screening out a corresponding first image of the positioning assisting device in the shape image; screening out, from the CT image, a corresponding second image of the positioning assisting device in the CT image; extracting a predetermined characteristic of the first image and a predetermined characteristic of the second image, respectively; implementing the image matching of the shape image and the CT image of the scanned subject by performing a characteristic matching on the predetermined characteristic of the first image and the predetermined characteristic of the second image.

6 . The method of claim 5 , said performing a characteristic matching on the predetermined characteristic of the first image and the predetermined characteristic of the second image comprises:
setting the predetermined characteristic of the first image to form a first predetermined pattern, and setting the predetermined characteristic of the second image to form a second predetermined pattern; calculating a rotation-and-translation matrix of converting the first predetermined pattern to the second predetermined pattern; and implementing the characteristic matching of the predetermined characteristic of the shape image and the predetermined characteristic of the CT image by performing a spatial transformation on the shape image based on the rotation-and-translation matrix.

7 . The method of claim 5 , wherein the predetermined characteristic comprises one or any number of combinations of an edge, a contour, a center, and a corner of a corresponding image of the positioning assisting device.

8 . The method of claim 4 , wherein the positioning assisting device comprises a plurality of markers.

9 . The method of claim 1 , said obtaining the supervision field projection data, and using the supervision projection data to correct the CT image comprises:
obtaining the supervision field projection data by orthographically projecting the supervision field image; and using the supervision projection data to correct the CT image.

10 . The method of claim 9 , wherein said obtaining the supervision projection data by orthographically projecting the supervision field image comprises:
filling an initial CT value in the supervision field; and obtain the supervision projection data by generating a CT attenuation value by using a simulated X-ray to irradiate the filled supervision field.

11 . A device for CT image correction, the device comprising:
a processor configured to execute machine-readable instructions corresponding to a control logic for CT image correction stored on a storage medium, wherein the machine-readable instructions, when executed, cause the processor to: obtain contour data of a scanned subject, and reconstruct a shape image of the scanned subject according to the contour data, wherein the contour data of the scanned subject is obtained by scanning the scanned subject through a piece of visual equipment; obtain original CT projection data of the scanned subject, and reconstruct a CT image according to the original CT projection data; perform image matching between the shape image and the CT image of the scanned subject for determining a supervision field image; and obtain a supervision projection data, and use the supervision projection data to correct the CT image.

12 . The device according to claim 11 , wherein said machine readable instructions further cause the processor to:
obtain scan data by scanning the scanned subject using the visual equipment; reconstruct an original visual image of the scanned subject according to the scan data, wherein the reconstructed original visual image of the scanned subject comprises an image of the appendage blocking the scanned subject; and obtain the shape image of the scanned subject by removing the image of the appendage from the original visual image of the scanned subject.

13 . The device according to claim 11 , wherein said machine readable instructions further cause the processor to:
obtain a relative position relationship between the shape image and the CT image according to a consistency between the shape image and the CT image of the scanned subject in space; and perform the image matching on the shape image and the CT image of the scanned subject according to the relative position relationship.

14 . The device according to claim 11 , further comprising:
a positioning assisting device, placed on the scanned subject, wherein the positioning assisting device is used to assist the image matching of the shape image and the CT image.

15 . The device according to claim 14 , wherein said machine readable instructions further cause the processor to:
provide the shape image and the CT image of the scanned subject, respectively; perform image segmentation on the shape image for screening out a corresponding first image of the positioning assisting device in the shape image; screen out, from the CT image, a corresponding second image of the positioning assisting device in the CT image; extract a predetermined characteristic of the first image and a predetermined characteristic of the second im

Assignees

• Shenyang Neusoft Medical Sys

Inventors

• Lou Shanshan
• Liu Changkun
• Wang Hongbo

Classifications

• G06T12/10

  Image preprocessing, e.g. calibration, positioning of sources or scatter correction · CPC title

• A61B6/5205 Primary

  involving processing of raw data to produce diagnostic data · CPC title

• A61B6/5258

  involving detection or reduction of artifacts or noise · CPC title

• A61B6/0492

  using markers or indicia for aiding patient positioning · CPC title

• A61B6/032

  Transmission computed tomography [CT] · CPC title