3D Motion Artifact Compensation in CT image with Depth Camera

People

Youngjun Ko, Jongduk Baek and Hyunjung Shim

Abstract

  Computed tomography (CT) is a medical imaging technology that projects computer-processed X-rays to acquire tomographic images or the slices of specific organ of body. A motion artifact caused by patient motion is a common problem in CT system and may introduce undesirable artifacts in CT images. This paper analyzes the critical problems in motion artifacts and proposes a new CT system for motion artifact compensation. We employ depth cameras to capture the patient motion and account it for the CT image reconstruction. In this way, we achieve the significant improvement in motion artifact compensation, which is not possible by previous techniques.

Overview

                            Geometry of propose method                           Schematic diagram of propose method

  We introduce a new motion-free CT system to handle personalized motions using depth cameras. Because the depth camera is effective for the motion capture, motion estimation can be performed effectively from depth video taken by depth cameras. Since we extract the accurate patient motion data using depth cameras, we alleviate the errors of motion assumption in the previous approach. With the exact patient motion data, we modify the raw measurements (referred to as sinogram) that are corrupted by a patient motion and minimize motion artifacts in the reconstructed CT images.

Results

  We simulated translating cube and ellipse. By extracting the translation motion, we modified corrupted sinogram and figured non-artifact images out. The simulation results are shown below.

                                      (a)                                         (b)                                             (c)                                         (d)

Simulated data; (a) translating cube, (b) corrected cube by our method, (c) translating ellipse and (d) corrected ellipse by our method 

As shown in pictures, we successfully modified the translation motion artifact.

Publification

3D Motion Artifact Compensation in CT image with Depth Camera

 Y Ko, J Baek, H Shim, IS&T/SPIE Electronic Imaging, 2015