title: Quantitative analysis of respiration-related movement for abdominal artery in multiphase hepatic CT.
abstract: OBJECTIVE
  Respiration-induced motion in the liver causes potential errors on the measurement of contrast medium in abdominal artery from multiphase hepatic CT scans. In this study, we investigated the use of hepatic CT images to quantitatively estimate the abdominal artery motion due to respiration by optical flow method.
  
  
  METHODS
  A total of 132 consecutive patients were included in our patient cohort. We apply the optical flow method to compute the motion of the abdominal artery due to respiration.
  
  
  RESULTS
  The minimum and maximum displacement of the abdominal artery motion were 0.02 and 30.87 mm by manual delineation, 0.03 and 40.75 mm calculated by optical flow method, respectively. Both high consistency and correlation between the present method and the physicians' manual delineations were acquired with the regression equation of movement, y = 0.81x + 0.25, r = 0.95, p < 0.001.
  
  
  CONCLUSIONS
  We estimated the motion of abdominal artery due to respiration using the optical flow method in multiphase hepatic CT scans and the motion estimations were validated with the visualization of physicians. The quantitative analysis of respiration-related movement of abdominal artery could be used for motion correction in the measurement of contrast medium passing though abdominal artery in multiphase CT liver scans.
authors.affiliation: Department of Diagnostic Radiology, Peng Hu Hospital, Ministry of Health and Welfare, Peng Hu City, Taiwan.
authors.forename: Yang-Hsien
authors.initials: YH
authors.lastname: Lin
authors.affiliation: Department of Radiology, China Medical University Hospital, Taichung City, Taiwan.
authors.forename: Shih-Min
authors.initials: SM
authors.lastname: Huang
authors.affiliation: Department of Diagnostic Radiology, Peng Hu Hospital, Ministry of Health and Welfare, Peng Hu City, Taiwan.
authors.forename: Chin-Yi
authors.initials: CY
authors.lastname: Huang
authors.affiliation: Department of Diagnostic Radiology, Peng Hu Hospital, Ministry of Health and Welfare, Peng Hu City, Taiwan.
authors.forename: Yun-Niang
authors.initials: YN
authors.lastname: Tu
authors.forename: Shing-Hong
authors.initials: SH
authors.lastname: Liu
authors.affiliation: Department of Biomedical Imaging and Radiological Science, China Medical University, Taichung City, Taiwan; Department of Biomedical Informatics, Asia University, Taichung City, Taiwan.
authors.forename: Tzung-Chi
authors.initials: TC
authors.lastname: Huang
mesh_terms: D000005:Abdomen / Q000098:blood supply*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001158:Arteries / Q000502:physiology*; D016477:Artifacts; D005260:Female; D006801:Humans; D008099:Liver / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D009068:Movement; D012044:Regression Analysis; D012119:Respiration; D014057:Tomography, X-Ray Computed / Q000379:methods*