title: Free-breathing 3D cardiac MRI using iterative image-based respiratory motion correction.
abstract: Respiratory motion compensation using diaphragmatic navigator gating with a 5 mm gating window is conventionally used for free-breathing cardiac MRI. Because of the narrow gating window, scan efficiency is low resulting in long scan times, especially for patients with irregular breathing patterns. In this work, a new retrospective motion compensation algorithm is presented to reduce the scan time for free-breathing cardiac MRI that increasing the gating window to 15 mm without compromising image quality. The proposed algorithm iteratively corrects for respiratory-induced cardiac motion by optimizing the sharpness of the heart. To evaluate this technique, two coronary MRI datasets with 1.3 mm(3) resolution were acquired from 11 healthy subjects (seven females, 25 ± 9 years); one using a navigator with a 5 mm gating window acquired in 12.0 ± 2.0 min and one with a 15 mm gating window acquired in 7.1 ± 1.0 min. The images acquired with a 15 mm gating window were corrected using the proposed algorithm and compared to the uncorrected images acquired with the 5 and 15 mm gating windows. The image quality score, sharpness, and length of the three major coronary arteries were equivalent between the corrected images and the images acquired with a 5 mm gating window (P-value > 0.05), while the scan time was reduced by a factor of 1.7.
authors.affiliation: Department of Medicine (Cardiovascular Division), Harvard Medical School and Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA.
authors.forename: Mehdi H
authors.initials: MH
authors.lastname: Moghari
authors.forename: Sébastien
authors.initials: S
authors.lastname: Roujol
authors.forename: Raymond H
authors.initials: RH
authors.lastname: Chan
authors.forename: Susie N
authors.initials: SN
authors.lastname: Hong
authors.forename: Natalie
authors.initials: N
authors.lastname: Bello
authors.forename: Markus
authors.initials: M
authors.lastname: Henningsson
authors.forename: Long H
authors.initials: LH
authors.lastname: Ngo
authors.forename: Beth
authors.initials: B
authors.lastname: Goddu
authors.forename: Lois
authors.initials: L
authors.lastname: Goepfert
authors.forename: Kraig V
authors.initials: KV
authors.lastname: Kissinger
authors.forename: Warren J
authors.initials: WJ
authors.lastname: Manning
authors.forename: Reza
authors.initials: R
authors.lastname: Nezafat
mesh_terms: D000328:Adult; D000465:Algorithms; D016477:Artifacts; D003331:Coronary Vessels / Q000033:anatomy & histology*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D008297:Male; D009038:Motion; D015203:Reproducibility of Results; D015656:Respiratory Mechanics; D055425:Respiratory-Gated Imaging Techniques / Q000379:methods*; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted
keywords: coronary MRI; diaphragmatic navigators; respiratory motion; retrospective motion correction