title: Image registration and analysis for quantitative myocardial perfusion: application to dynamic circular cardiac CT.
abstract: Large area detector computed tomography systems with fast rotating gantries enable volumetric dynamic cardiac perfusion studies. Prospectively, ECG-triggered acquisitions limit the data acquisition to a predefined cardiac phase and thereby reduce x-ray dose and limit motion artefacts. Even in the case of highly accurate prospective triggering and stable heart rate, spatial misalignment of the cardiac volumes acquired and reconstructed per cardiac cycle may occur due to small motion pattern variations from cycle to cycle. These misalignments reduce the accuracy of the quantitative analysis of myocardial perfusion parameters on a per voxel basis. An image-based solution to this problem is elastic 3D image registration of dynamic volume sequences with variable contrast, as it is introduced in this contribution. After circular cone-beam CT reconstruction of cardiac volumes covering large areas of the myocardial tissue, the complete series is aligned with respect to a chosen reference volume. The results of the registration process and the perfusion analysis with and without registration are evaluated quantitatively in this paper. The spatial alignment leads to improved quantification of myocardial perfusion for three different pig data sets.
authors.affiliation: Philips Research Laboratories, X-ray Imaging Systems Department, Weisshausstrasse 2, D-52066 Aachen, Germany. Alfonso.Isola@Philips.com
authors.forename: A A
authors.initials: AA
authors.lastname: Isola
authors.forename: H
authors.initials: H
authors.lastname: Schmitt
authors.forename: U
authors.initials: U
authors.lastname: van Stevendaal
authors.forename: P G
authors.initials: PG
authors.lastname: Begemann
authors.forename: P
authors.initials: P
authors.lastname: Coulon
authors.forename: L
authors.initials: L
authors.lastname: Boussel
authors.forename: M
authors.initials: M
authors.lastname: Grass
mesh_terms: D000818:Animals; D002319:Cardiovascular System; D054893:Cone-Beam Computed Tomography / Q000379:methods*; D003326:Coronary Circulation / Q000502:physiology; D006321:Heart / Q000000981:diagnostic imaging* / Q000502:physiology; D006339:Heart Rate; D006439:Hemodynamics; D021621:Imaging, Three-Dimensional / Q000379:methods*; D023421:Models, Animal; D009038:Motion; D055414:Myocardial Perfusion Imaging / Q000379:methods*; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013552:Swine