title: A spin echo sequence with a single-sided bipolar diffusion gradient pulse to obtain snapshot diffusion weighted images in moving media.
abstract: In vivo MRI data can be corrupted by motion. Motion artifacts are particularly troublesome in Diffusion Weighted MRI (DWI), since the MR signal attenuation due to Brownian motion can be much less than the signal loss due to dephasing from other types of complex tissue motion, which can significantly degrade the estimation of self-diffusion coefficients, diffusion tensors, etc. This paper describes a snapshot DWI sequence, which utilizes a novel single-sided bipolar diffusion sensitizing gradient pulse within a spin echo sequence. The proposed method shortens the diffusion time by applying a single refocused bipolar diffusion gradient on one side of a refocusing RF pulse, instead of a set of diffusion sensitizing gradients, separated by a refocusing RF pulse, while reducing the impact of magnetic field inhomogeneity by using a spin echo sequence. A novel MRI phantom that can exhibit a range of complex motions was designed to demonstrate the robustness of the proposed DWI sequence.
authors: Division of Computational Bioscience, Center for Information Technology, National Institutes of Health, Bethesda, MD, USA. raisa@helix.nih.gov
authors: R Z
authors: RZ
authors: Freidlin
authors: J W
authors: JW
authors: Kakareka
authors: T J
authors: TJ
authors: Pohida
authors: M E
authors: ME
authors: Komlosh
authors: P J
authors: PJ
authors: Basser
mesh_terms: D000465:Algorithms; D000818:Animals; D016477:Artifacts; D003287:Contrast Media; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D019786:Gadolinium DTPA; D006321:Heart / Q000033:anatomy & histology / Q000502:physiology; D009038:Motion; D019047:Phantoms, Imaging; D015656:Respiratory Mechanics / Q000502:physiology; D013116:Spinal Cord / Q000033:anatomy & histology; D013552:Swine
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA