title: Free-breathing cardiac MR with a fixed navigator efficiency using adaptive gating window size.
abstract: A respiratory navigator with a fixed acceptance gating window is commonly used to reduce respiratory motion artifacts in cardiac MR. This approach prolongs the scan time and occasionally yields an incomplete dataset due to respiratory drifts. To address this issue, we propose an adaptive gating window approach in which the size and position of the gating window are changed adaptively during the acquisition based on the individual's breathing pattern. The adaptive gating window tracks the breathing pattern of the subject throughout the scan and adapts the size and position of the gating window such that the gating efficiency is always fixed at a constant value. To investigate the image quality and acquisition time, free breathing cardiac MRI, including both targeted coronary MRI and late gadolinium enhancement imaging, was performed in 67 subjects using the proposed navigator technique. Targeted coronary MRI was acquired from eleven healthy adult subjects using both the conventional and proposed adaptive gating window techniques. Fifty-six patients referred for cardiac MRI were also imaged using late gadolinium enhancement with the proposed adaptive gating window technique. Subjective and objective image assessments were used to evaluate the proposed method. The results demonstrate that the proposed technique allows free-breathing cardiac MRI in a relatively fixed time without compromising imaging quality due to respiratory motion artifacts.
authors.affiliation: Department of Medicine, Cardiovascular Division, Harvard Medical School and Beth Israel Deaconess Medical Center, Boston, Massachusetts 02215, USA.
authors.forename: Mehdi H
authors.initials: MH
authors.lastname: Moghari
authors.forename: Raymond H
authors.initials: RH
authors.lastname: Chan
authors.forename: Susie N
authors.initials: SN
authors.lastname: Hong
authors.forename: Jaime L
authors.initials: JL
authors.lastname: Shaw
authors.forename: Lois A
authors.initials: LA
authors.lastname: Goepfert
authors.forename: Kraig V
authors.initials: KV
authors.lastname: Kissinger
authors.forename: Beth
authors.initials: B
authors.lastname: Goddu
authors.forename: Mark E
authors.initials: ME
authors.lastname: Josephson
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; D062485:Breath Holding; D003287:Contrast Media; D005260:Female; D019786:Gadolinium DTPA; D006331:Heart Diseases / Q000175:diagnosis*; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009038:Motion; D015203:Reproducibility of Results; D055425:Respiratory-Gated Imaging Techniques / Q000379:methods*; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA