title: MRI monitoring of laser ablation using optical flow.
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).
authors.affiliation: Department of Radiology, Harvard Medical School and Brigham and Women's Hospital, Boston, MA 02115, USA. zientara@bwh.harvard.edu
authors.forename: G P
authors.initials: GP
authors.lastname: Zientara
authors.forename: P
authors.initials: P
authors.lastname: Saiviroonporn
authors.forename: P R
authors.initials: PR
authors.lastname: Morrison
authors.forename: M P
authors.initials: MP
authors.lastname: Fried
authors.forename: S G
authors.initials: SG
authors.lastname: Hushek
authors.forename: R
authors.initials: R
authors.lastname: Kikinis
authors.forename: F A
authors.initials: FA
authors.lastname: Jolesz
mesh_terms: D000180:Acrylic Resins; D000818:Animals; D005782:Gels; D007091:Image Processing, Computer-Assisted; D017075:Laser Coagulation; D008099:Liver / Q000033:anatomy & histology* / Q000601:surgery; D008279:Magnetic Resonance Imaging; D008962:Models, Theoretical; D016343:Monitoring, Intraoperative / Q000379:methods*; D055095:Optics and Photonics; D019047:Phantoms, Imaging; D011817:Rabbits; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D000099166:Polyacrylamides
chemical_list: D000180:Acrylic Resins; D005782:Gels; D000099166:Polyacrylamides