title: Co-registration of acquired MR ventilation and perfusion images--validation in a porcine model.
abstract: Under controlled imaging conditions, functional, co-registered ventilation and perfusion images were obtained for quantitative MRI assessment of pulmonary function. Experiments were conducted on 25-35 kg Yorkshire pigs (N = 5) under ketamine/isoflurane anesthesia. Ventilation and perfusion MR images were obtained using laser polarized gas and gadolinium (Gd), respectively. The mutual information-based technique was used to quantify the initial misregistration between the acquired ventilation and perfusion images, to cope with different intensity characteristics. Means and standard deviations (SDs) of misregistrations for the five subjects, in terms of absolute translation and absolute rotations around each of the three coordinate axes, were computed to evaluate the hypothesis. For qualitative illustrations, plots of mutual information values under absolute translations and rotations around each of the three coordinate axes are presented. This preliminary study shows the feasibility of acquiring functional image data that are spatially co-registered. This method has potential applications in the quantitative assessment of regional alveolar ventilation and pulmonary perfusion ratio, in both normal and diseased lung.
authors.affiliation: Department of Radiology, Metabolic Magnetic Resonance Research and Computing Center, University of Pennsylvania, Philadelphia 19104, USA. rrizi@ginger.mmrrcc.upenn.edu
authors.forename: Rahim R
authors.initials: RR
authors.lastname: Rizi
authors.forename: Punam K
authors.initials: PK
authors.lastname: Saha
authors.forename: Binquan
authors.initials: B
authors.lastname: Wang
authors.forename: Margaret A
authors.initials: MA
authors.lastname: Ferrante
authors.forename: David
authors.initials: D
authors.lastname: Lipson
authors.forename: James
authors.initials: J
authors.lastname: Baumgardner
authors.forename: David A
authors.initials: DA
authors.lastname: Roberts
mesh_terms: D000818:Animals; D005682:Gadolinium; D006371:Helium; D007091:Image Processing, Computer-Assisted; D007554:Isotopes; D008279:Magnetic Resonance Imaging; D011652:Pulmonary Circulation; D012123:Pulmonary Ventilation; D013552:Swine; D014692:Ventilation-Perfusion Ratio
chemical_list: D007554:Isotopes; D006371:Helium; D005682:Gadolinium