title: Semi-automated brain tumor and edema segmentation using MRI.
abstract: OBJECTIVE
  Manual segmentation of brain tumors from magnetic resonance images is a challenging and time-consuming task. A semi-automated method has been developed for brain tumor and edema segmentation that will provide objective, reproducible segmentations that are close to the manual results. Additionally, the method segments non-enhancing brain tumor and edema from healthy tissues in magnetic resonance images.
  
  
  METHODS
  In this study, a semi-automated method was developed for brain tumor and edema segmentation and volume measurement using magnetic resonance imaging (MRI). Some novel algorithms for tumor segmentation from MRI were integrated in this medical diagnosis system. We exploit a hybrid level set (HLS) segmentation method driven by region and boundary information simultaneously, region information serves as a propagation force which is robust and boundary information serves as a stopping functional which is accurate. Ten different patients with brain tumors of different size, shape and location were selected, a total of 246 axial tumor-containing slices obtained from 10 patients were used to evaluate the effectiveness of segmentation methods.
  
  
  RESULTS
  This method was applied to 10 non-enhancing brain tumors and satisfactory results were achieved. Two quantitative measures for tumor segmentation quality estimation, namely, correspondence ratio (CR) and percent matching (PM), were performed. For the segmentation of brain tumor, the volume total PM varies from 79.12 to 93.25% with the mean of 85.67+/-4.38% while the volume total CR varies from 0.74 to 0.91 with the mean of 0.84+/-0.07. For the segmentation of edema, the volume total PM varies from 72.86 to 87.29% with the mean of 79.54+/-4.18% while the volume total CR varies from 0.69 to 0.85 with the mean of 0.79+/-0.08. The HLS segmentation method perform better than the classical level sets (LS) segmentation method in PM and CR.
  
  
  CONCLUSIONS
  The results of this research may have potential applications, both as a staging procedure and a method of evaluating tumor response during treatment, this method can be used as a clinical image analysis tool for doctors or radiologists.
authors.affiliation: Institute of Image Processing & Pattern Recognition, Shanghai Jiaotong University, 200030 Shanghai, China. xie_kai2001@sjtu.edu.cn
authors.forename: Kai
authors.initials: K
authors.lastname: Xie
authors.forename: Jie
authors.initials: J
authors.lastname: Yang
authors.forename: Z G
authors.initials: ZG
authors.lastname: Zhang
authors.forename: Y M
authors.initials: YM
authors.lastname: Zhu
mesh_terms: D000465:Algorithms; D001921:Brain / Q000473:pathology*; D001929:Brain Edema / Q000175:diagnosis*; D001932:Brain Neoplasms / Q000175:diagnosis* / Q000473:pathology; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008577:Meningeal Neoplasms / Q000175:diagnosis* / Q000473:pathology; D008579:Meningioma / Q000175:diagnosis* / Q000473:pathology; D009367:Neoplasm Staging / Q000379:methods; D018302:Neoplasms, Neuroepithelial / Q000175:diagnosis* / Q000473:pathology; D015588:Observer Variation; D019047:Phantoms, Imaging; D011379:Prognosis; D015203:Reproducibility of Results; D047368:Tumor Burden / Q000502:physiology