title: Virtual dye angiography: flow visualization for MRI-guided interventions.
abstract: In magnetic resonance imaging-guided cardiovascular interventional procedures, it is valuable to be able to visualize blood flow immediately and interactively in selected regions. In particular, it is useful to assess normal or pathological communications between specific heart chambers and vessels. Phase-contrast velocity mapping is not suitable for this purpose as it requires too much data and is not capable of determining directly if blood originating in one location travels to a nearby location. This article presents a novel flow visualization method called virtual dye angiography that enables visualization of blood flow analogous to selective catheter angiography. The method uses two-dimensional radio frequency pulses to achieve interactive, intermittent, targeted saturation of a localized region of the blood pool. The flow of the saturated spins is observed directly on real-time images or, in an enhanced manner, using ECG synchronized background subtraction. The modular nature of the technique allows for easy and seamless integration into a real-time, interactive imaging system with minimal overhead. We present initial results in animals and in a healthy human volunteer.
authors.affiliation: National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA.
authors.forename: Ashvin K
authors.initials: AK
authors.lastname: George
authors.forename: Anthony Z
authors.initials: AZ
authors.lastname: Faranesh
authors.forename: Kanishka
authors.initials: K
authors.lastname: Ratnayaka
authors.forename: J Andrew
authors.initials: JA
authors.lastname: Derbyshire
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Lederman
authors.forename: Michael S
authors.initials: MS
authors.lastname: Hansen
mesh_terms: D000818:Animals; D001013:Aorta, Thoracic / Q000502:physiology*; D016477:Artifacts; D001783:Blood Flow Velocity; D055424:Cardiac-Gated Imaging Techniques; D003326:Coronary Circulation / Q000502:physiology*; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007091:Image Processing, Computer-Assisted / Q000379:methods; D018810:Magnetic Resonance Angiography / Q000379:methods*; D053783:Magnetic Resonance Imaging, Interventional / Q000379:methods*; D019047:Phantoms, Imaging; D013552:Swine