title: Experimental Evaluation of a Deformable Registration Algorithm for Motion Correction in PET-CT Guided Biopsy.
abstract: Positron emission tomography computed tomography (PET-CT) images are increasingly being used for guidance during percutaneous biopsy. However, due to the physics of image acquisition, PET-CT images are susceptible to problems due to respiratory and cardiac motion, leading to inaccurate tumor localization, shape distortion, and attenuation correction. To address these problems, we present a method for motion correction that relies on respiratory gated CT images aligned using a deformable registration algorithm. In this work, we use two deformable registration algorithms and two optimization approaches for registering the CT images obtained over the respiratory cycle. The two algorithms are the BSpline and the symmetric forces Demons registration. In the first optmization approach, CT images at each time point are registered to a single reference time point. In the second approach, deformation maps are obtained to align each CT time point with its adjacent time point. These deformations are then composed to find the deformation with respect to a reference time point. We evaluate these two algorithms and optimization approaches using respiratory gated CT images obtained from 7 patients. Our results show that overall the BSpline registration algorithm with the reference optimization approach gives the best results.
authors.affiliation: Children's National Medical Center, Washington, DC 20010 USA.
authors.forename: Rahul
authors.initials: R
authors.lastname: Khare
authors.affiliation: Kitware Inc., Carrboro, NC USA.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Sala
authors.affiliation: University of Washington, Seattle, WA, USA.
authors.forename: Paul
authors.initials: P
authors.lastname: Kinahan
authors.affiliation: Georgetown University hospital, Washington, DC, USA.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Esposito
authors.affiliation: Georgetown University hospital, Washington, DC, USA.
authors.forename: Filip
authors.initials: F
authors.lastname: Banovac
authors.affiliation: Children's National Medical Center, Washington, DC 20010 USA.
authors.forename: Kevin
authors.initials: K
authors.lastname: Cleary
authors.affiliation: Kitware Inc., Carrboro, NC USA.
authors.forename: Andinet
authors.initials: A
authors.lastname: Enquobahrie
keywords: PET-CT; deformable registration; image-guided surgery; motion correction