title: New parametric imaging method with fluorescein angiograms for detecting areas of capillary nonperfusion.
abstract: OBJECTIVE
  Fluorescein angiography (FAG) is currently the most useful diagnostic modality for examining retinal circulation, and it is frequently used for the evaluation of patients with diabetic retinopathy, occlusive diseases, such as retinal venous and arterial occlusions, and wet macular degeneration. This paper presents a method for objectively evaluating retinal circulation by quantifying circulation-related parameters.
  
  
  METHODS
  This method allows the semiautomatic preprocessing and registering of FAG images. The arterial input function is estimated from the registered set of FAG images using gamma-variate fitting. Then, the parameters can be computed by deconvolution on the basis of truncated singular value decomposition, and they can finally be presented as parametric color images in a combination of three colors, red, green, and blue.
  
  
  RESULTS
  After the estimation of arterial input function, the parameters of relative blood flow and mean transit time were computed using deconvolution analysis based on truncated singular value decomposition.
  
  
  CONCLUSIONS
  The parametric color image is helpful to interpret the status of retinal blood circulation and provides quantitative data on retina ischemia without interobserver variability. This system easily provides the status of retinal blood circulation both qualitatively and quantitatively. It also helps to standardize FAG interpretation and may contribute to network-based telemedicine systems in the future.
authors.affiliation: Biomedical Engineering Branch, Division of Convergence Technology, Research Institute, National Cancer Center, Goyang, Korea. ; Department of Plasma Bio Display, Kwangwoon Universiy, Seoul, Korea.
authors.forename: Young Jae
authors.initials: YJ
authors.lastname: Kim
authors.affiliation: Biomedical Engineering Branch, Division of Convergence Technology, Research Institute, National Cancer Center, Goyang, Korea.
authors.forename: Chang Bu
authors.initials: CB
authors.lastname: Jeong
authors.affiliation: Department of Ophthalmology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea.
authors.forename: Jeong-Min
authors.initials: JM
authors.lastname: Hwang
authors.affiliation: Department of Ophthalmology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea.
authors.forename: Hee Kyung
authors.initials: HK
authors.lastname: Yang
authors.affiliation: Department of Plasma Bio Display, Kwangwoon Universiy, Seoul, Korea.
authors.forename: Seung Hyun
authors.initials: SH
authors.lastname: Lee
authors.affiliation: Biomedical Engineering Branch, Division of Convergence Technology, Research Institute, National Cancer Center, Goyang, Korea.
authors.forename: Kwang Gi
authors.initials: KG
authors.lastname: Kim
keywords: Biomedical Engineering; Computer-Assisted Diagnosis; Eye Disease; Fluorescein Angiography; Ophthalmology