author = {G.~P.~Zientara and P.~Saiviroonporn  and P.~R.~Morrison and M.~P.~Fried and S.~G.~Hushek and R.~Kikinis and F.~A.~Jolesz},
  title = {{MRI Monitoring of Laser Ablation Using Optical Flow}},
  volume = 8,
  number = 6,
  pages = {1306-1318},
  year = {1998},
  abstract = {The optical flow method is used for visualizing and quantifying the
dynamics of tissue changes observed by MRI during thermal ablations. An
approach was implemented for parallel two-dimensional optical flow
calculations including the replacement of spurious velocities. Velocity
magnitude results were found to be accurate in low-noise cases in tests
using series of synthetic images. Optical flow results are presented
from thermal ablation experiments utilizing a homogeneous polyacrylamide
gel phantom and heterogeneous rabbit liver tissue in vivo, exhibiting
heating and cooling with the accompanying quantitative characterization
of the dilation and contraction of the thermally affected region.
Results demonstrate that optical flow is capable of noninvasive
real-time monitoring and control of interstitial laser therapy (ILT).  }