title: Expiration-phase template-based motion correction of free-breathing abdominal dynamic contrast enhanced MRI.
abstract: This paper studies a novel method to compensate for respiratory and peristaltic motions in abdominal dynamic contrast enhanced magnetic resonance imaging. The method consists of two steps: 1) expiration-phase "template" construction and retrospective gating of the data to the template; and 2) nonrigid registration of the gated volumes. Landmarks annotated by three experts were used to directly assess the registration performance. A tri-exponential function fit to time intensity curves from regions of interest was used to indirectly assess the performance. One of the parameters of the tri-exponential fit was used to quantify the contrast enhancement. Our method achieved a mean target registration error (MTRE) of 2.12, 2.27, and 2.33 mm with respect to annotations by expert, which was close to the average interobserver variability (2.07 mm). A state-of-the-art registration method achieved an MTRE of 2.83-3.10 mm. The correlation coefficient of the contrast enhancement parameter to the Crohn's disease endoscopic index of Severity (r = 0.60, p = 0.004) was higher than the correlation coefficient for the relative contrast enhancement measurements values of two observers ( r(Observer 1) = 0.29, p = 0.2; r(Observer 2) = 0.45, p = 0.04). Direct and indirect assessments show that the expiration-based gating and a nonrigid registration approach effectively corrects for respiratory motion and peristalsis. The method facilitates improved enhancement measurement in the bowel wall in patients with Crohn's disease.
authors.affiliation: Quantitative Imaging Group, Delft University of Technology, Delft, The Netherlands.
authors.forename: Zhang
authors.initials: Z
authors.lastname: Li
authors.affiliation: Department of Radiology, Academic Medical Center.
authors.forename: Jeroen A W
authors.initials: JAW
authors.lastname: Tielbeek
authors.affiliation: Department of Radiology, Academic Medical Center.
authors.forename: Matthan W A
authors.initials: MWA
authors.lastname: Caan
authors.affiliation: Department of Radiology, Academic Medical Center.
authors.forename: Carl A J
authors.initials: CAJ
authors.lastname: Puylaert
authors.affiliation: Department of Radiology, Academic Medical Center.
authors.forename: Manon L W
authors.initials: MLW
authors.lastname: Ziech
authors.affiliation: Department of Radiology, Academic Medical Center.
authors.forename: Chung Y
authors.initials: CY
authors.lastname: Nio
authors.affiliation: Department of Radiology, Academic Medical Center.
authors.forename: Jaap
authors.initials: J
authors.lastname: Stoker
authors.affiliation: Quantitative Imaging Group, Delft University of Technology.
authors.forename: Lucas J
authors.initials: LJ
authors.lastname: van Vliet
authors.affiliation: Quantitative Imaging Group, Delft University of Technology.
authors.forename: Frans M
authors.initials: FM
authors.lastname: Vos
mesh_terms: D000005:Abdomen / Q000502:physiology; D003287:Contrast Media; D003424:Crohn Disease / Q000473:pathology / Q000503:physiopathology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D010528:Peristalsis / Q000502:physiology*; D015656:Respiratory Mechanics / Q000502:physiology*
chemical_list: D003287:Contrast Media