title: A false color fusion strategy for drusen and geographic atrophy visualization in optical coherence tomography images.
abstract: OBJECTIVE
  To display drusen and geographic atrophy (GA) in a single projection image from three-dimensional spectral domain optical coherence tomography images based on a novel false color fusion strategy.
  
  
  METHODS
  We present a false color fusion strategy to combine drusen and GA projection images. The drusen projection image is generated with a restricted summed-voxel projection (axial sum of the reflectivity values in a spectral domain optical coherence tomography cube, limited to the region where drusen is present). The GA projection image is generated by incorporating two GA characteristics: bright choroid and thin retina pigment epithelium. The false color fusion method was evaluated in 82 three-dimensional optical coherence tomography data sets obtained from 7 patients, for which 2 readers independently identified drusen and GA as the gold standard. The mean drusen and GA overlap ratio was used as the metric to determine accuracy of visualization of the proposed method when compared with the conventional summed-voxel projection, (axial sum of the reflectivity values in the complete spectral domain optical coherence tomography cube) technique and color fundus photographs.
  
  
  RESULTS
  Comparative results demonstrate that the false color image is more effective in displaying drusen and GA than summed-voxel projection and CFP. The mean drusen/GA overlap ratios based on the conventional summed-voxel projection method, color fundus photographs, and the false color fusion method were 6.4%/100%, 64.1%/66.7%, and 85.6%/100%, respectively.
  
  
  CONCLUSIONS
  The false color fusion method was more effective for simultaneous visualization of drusen and GA than the conventional summed-voxel projection method and color fundus photographs, and it seems promising as an alternative method for visualizing drusen and GA in the retinal fundus, which commonly occur together and can be confusing to differentiate without methods such as this proposed one.
authors: *School of Computer Science and Engineering, Nanjing University of Science and Technology, Nanjing, China; †Byers Eye Institute at Stanford, Stanford University School of Medicine, Palo Alto, California; and ‡Department of Radiology and Medicine (Biomedical Informatics Research), Stanford University School of Medicine, Stanford, California.
authors: Qiang
authors: Q
authors: Chen
authors: Theodore
authors: T
authors: Leng
authors: Sijie
authors: S
authors: Niu
authors: Jiajia
authors: J
authors: Shi
authors: Luis
authors: L
authors: de Sisternes
authors: Daniel L
authors: DL
authors: Rubin
mesh_terms: D003116:Color; D005654:Fundus Oculi; D057092:Geographic Atrophy / Q000175:diagnosis*; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D015593:Retinal Drusen / Q000175:diagnosis*; D055213:Retinal Pigment Epithelium / Q000473:pathology; D041623:Tomography, Optical Coherence / Q000379:methods*