@TechReport{Uhercik-TR-2009-11,
  IS = { zkontrolovano 25 Jan 2010 },
  UPDATE  = { 2009-09-29 },
author =      {Uher{\v c}{\'\i}k, Mari{\' a}n and
               Kybic, Jan and
               Liebgott, Herv{\'e} and
               Cachard, Christian},
title =       {Model Fitting using {RANSAC} for Surgical Tool
               Localization in {3D} Ultrasound Images},
institution = {Center for Machine Perception, K13133 FEE
               Czech Technical University},
address =     {Prague, Czech Republic},
year =        {2009},
month =       {September},
type =        {Research Report},
number =      {CTU--CMP--2009--11},
issn =        {1213-2365},
pages =       {7},
figures =     {8},
authorship =  {50-40-5-5},
psurl       = {[Uhercik-TR-2009-11.pdf]},
project =     {MEST-CT-021024 WARTHE, MSM6840770012},
annote = {Ultrasound guidance is used for many surgical interventions
  like biopsy or electrode insertion. We present a method for
  localization of a thin surgical tool such as a biopsy needle or a
  micro-electrode in a three dimensional (3D) ultrasound image. The
  proposed method starts with thresholding and model fitting using
  RANSAC for robust localization of the axis. Subsequent local
  optimization refines its position. Finally, the tip of the tool is
  localized by finding an intensity drop along the axis. Two different
  tool models are presented, one simple and fast, the second using a
  learnt a priori information about voxel intensities of the tool and
  the background. The simulation study shows that our algorithm can
  localize the tool at almost real time speed even using a Matlab
  implementation, with accuracy better than 1 mm. In experimental
  comparison to several alternative localization methods our method
  appears to be the fastest and the most robust one. We also show
  results on real 3D ultrasound data from a PVA cryogel phantom and
  breast biopsy.},
keywords =    {Medical Imaging, 3D ultrasound, electrode, needle,
localization, image guidance, RANSAC, randomized algorithm},
comment =     { Submitted to Transactions of Biomedical Engineering},
}