Fuzzy-based Segmentation Algorithm for Brain Images

퍼지기반의 두뇌영상 영역분할 알고리듬

  • Lee, Hyo-Jong (Div. Computer Science and Engineering, Chonbuk National University, CAIIT)
  • 이효종 (전북대학교 전기전자컴퓨터공학부, 영상정보신기술연구센터)
  • Published : 2009.12.25

Abstract

As technology gets developed, medical equipments are also modernized and leading-edge systems, such as PACS become popular. Many scientists noticed importance of medical image processing technology. Technique of region segmentation is the first step of digital medical image processing. Segmentation technique helps doctors to find out abnormal symptoms early, such as tumors, edema, and necrotic tissue, and helps to diagnoses correctly. Segmentation of white matter, gray matter and CSF of a brain image is very crucial part. However, the segmentation is not easy due to ambiguous boundaries and inhomogeneous physical characteristics. The rate of incorrect segmentation is high because of these difficulties. Fuzzy-based segmentation algorithms are robust to even ambiguous boundaries. In this paper a modified Fuzzy-based segmentation algorithm is proposed to handle the noise of MR scanners. A proposed algorithm requires minimal computations of mean and variance of neighbor pixels to adjust a new neighbor list. With the addition of minimal compuation, the modified FCM(mFCM) lowers the rate of incorrect clustering below 30% approximately compared the traditional FCM.

기술의 발달로 의료장비의 현대화가 이루어지고 PACS와 같은 시스템이 보편화되면서 디지털 의료영상처리 기술에 대한 관심이 높아지고 있다. 영역분할 기술은 디지털의료영상처리에서 첫 번째 단계로 필요한 전처리기술이다. 영역분할을 통하여 특정 부위가 종양, 부종, 파손 및 괴사세포와 같은 이상 현상을 나타내는 것을 조기에 발견할 수 있도록 해주고, 의사들이 적절한 처방을 내려줄 수 있도록 도와줄 수 있다. 특히 두뇌영상에서 백질, 회백질 및 CSF(cerebral spinal fluid)의 영역분할은 두뇌연구의 핵심기술이다. 이들 의료영상에서 기존의 윤곽선이나 영역 확장법은 애매한 경계선과 장기내의 물리적 특성이 비균질하여 영역분할의 실패율을 높게 한다. 퍼지기반의 영역분할 알고리듬은 불분명한 경계를 이루는 장기의 영역분할에 강하다고 알려져 있다. 본 연구에서는 자기공명영상이 강하게 나타내는 잡음에도 안정적인 퍼지기반의 영역분할 알고리듬을 제안하였다. 제안된 알고리듬은 이웃화소들을 군집시킬 때에 평균과 분산의 정보를 이용하여 최소한의 계산을 추가함으로써, 기존의 퍼지기반 영역분할 방법에 비하여 실패율이 대략 30% 이하로 낮은 것을 확인하였다.

Keywords

References

  1. S. Franchi, M. Imperato and F. Prampolini, 'Multimedia perspective for next generation PAC systems,' IEEE Symposium on Computer-Based Medical Systems, pp. 156-169 June 1992
  2. H. Suzuki and J. Toriwaki, 'Automatic segmentation of head MRI images by knowledge guided thresholding,' Computing Medical Imaging and Graphics, vol.15,no.4,pp.233–240, 1991 https://doi.org/10.1016/0895-6111(91)90081-6
  3. L. Lemieux, G. Hagemann, K. Krakow, and F. G. Woermann, 'Fast, accurate, and reproducible automatic segmentation of the brain in T1-weighted volume MRI data,' Magn. Reson. Med.,vol.42,pp.127–135,1999 https://doi.org/10.1002/(SICI)1522-2594(199907)42:1<127::AID-MRM17>3.0.CO;2-O
  4. L. O. Hall, A. M. Bensaid, L. P. Clarke, R. P. Velthuizen, M. S. Silbiger, and J. C. Bezdek, 'A comparison of neural network and fuzzy clustering techniques in segmenting magnetic resonance images of the brain,' IEEE Trans. Neural Netw.,vol.3,no.5,pp.672–682,Sep.1992 https://doi.org/10.1109/72.159057
  5. D. L. Pham and J. L. Prince, 'Adaptive fuzzy segmentation of magnetic resonance images,' IEEE Trans. Med. Imag., vol. 18, no. 9, pp. 737–752, Sep. 1999 https://doi.org/10.1109/42.802752
  6. A. R. Robb, 'Biomedical Imaging, Visualization, and Analysis.' New York: Wiley, 2000
  7. R. Pohle and K. D. Toennies, 'Segmentation of medical images using adaptive region growing,' Proc. SPIE- Med. Imag., vol. 4322, pp.1337–1346, 2001
  8. T. Y. Law and P. A. Heng, 'Automated extraction of bronchus from 3D CT images of lung based on genetic algorithm and 3D region growing,' Proc.SPIE-Med. Imag., vol. 3979, pp. 906–916, 2000
  9. Y. A. Tolias and S. M. Panas. 'Image segmentation by a fuzzy clustering algorithm using adaptive spatially constrained membership fucntions.' IEEE Trans. on Systems, Man, and Cybernetics-PartA, vol. 28, no. 3, pp. 359-369, 1998 https://doi.org/10.1109/3468.668967
  10. J. C. Bezdek, 'Pattern Recognition with Fuzzy Objective Function Algorithms.' New York: Plenum, 1981
  11. J. C. Bezdek, L. O. Hall, and L. P. Clark, "Review of MR image segmentation techniques using pattern recognition," Med. Phys., vol. 20, pp. 1033–1048, 1993 https://doi.org/10.1118/1.597000
  12. A. Simmons, P. S. Tofts, G. J. Barker and S. R. Arridge, 'Sources of intensity nonuniformity in spin echo images at 1.5T,' Magn. Reson. Med., vol. 32, pp. 121-128, 1994 https://doi.org/10.1002/mrm.1910320117
  13. S. Shen, W. Sandham, M. Granat and A. Sterr, 'MRI Fuzzy segmentation of brain tissue using neighborhood attraction with neural-network optimization,' IEEE Transactions on information technology in biomedicine, vol. 9, no. 3, pp. 459-467, September 2005 https://doi.org/10.1109/TITB.2005.847500