title: UTE-ΔR2 -ΔR2 * combined MR whole-brain angiogram using dual-contrast superparamagnetic iron oxide nanoparticles.
abstract: The ability to visualize whole-brain vasculature is important for quantitative in vivo investigation of vascular malfunctions in cerebral small vessel diseases, including cancer, stroke and neurodegeneration. Transverse relaxation-based ΔR2 and ΔR2 * MR angiography (MRA) provides improved vessel-tissue contrast in animal deep brain with the aid of intravascular contrast agents; however, it is susceptible to orientation dependence, air-tissue interface artifacts and vessel size overestimation. Dual-mode MRA acquisition with superparamagnetic iron oxide nanoparticles (SPION) provides a unique opportunity to systematically compare and synergistically combine both longitudinal (R1 ) and transverse (ΔR2 and ΔR2 *) relaxation-based MRA. Through Monte Carlo (MC) simulation and MRA experiments in normal and tumor-bearing animals with intravascular SPION, we show that ultrashort TE (UTE) MRA acquires well-defined vascularization on the brain surface, minimizing air-tissue artifacts, and combined ΔR2 and ΔR2 * MRA simultaneously improves the sensitivity to intracortical penetrating vessels and reduces vessel size overestimation. Consequently, UTE-ΔR2 -ΔR2 * combined MRA complements the shortcomings of individual angiograms and provides a strategy to synergistically merge longitudinal and transverse relaxation effects to generate more robust in vivo whole-brain micro-MRA. Copyright © 2016 John Wiley & Sons, Ltd.
authors.affiliation: Department of Biomedical Engineering, Ulsan National Institute of Science and Technology, Ulsan, South Korea.
authors.forename: H S
authors.initials: HS
authors.lastname: Jung
authors.affiliation: Department of Biomedical Engineering, Ulsan National Institute of Science and Technology, Ulsan, South Korea.
authors.forename: S H
authors.initials: SH
authors.lastname: Jin
authors.affiliation: Department of Biomedical Engineering, Ulsan National Institute of Science and Technology, Ulsan, South Korea.
authors.forename: J H
authors.initials: JH
authors.lastname: Cho
authors.affiliation: Department of Biomedical Engineering, Ulsan National Institute of Science and Technology, Ulsan, South Korea.
authors.forename: S H
authors.initials: SH
authors.lastname: Han
authors.affiliation: Department of Biomedical Engineering, Ulsan National Institute of Science and Technology, Ulsan, South Korea.
authors.forename: D K
authors.initials: DK
authors.lastname: Lee
authors.affiliation: Department of Biomedical Engineering, Ulsan National Institute of Science and Technology, Ulsan, South Korea.
authors.forename: H
authors.initials: H
authors.lastname: Cho
mesh_terms: D000818:Animals; D001932:Brain Neoplasms / Q000098:blood supply / Q000000981:diagnostic imaging* / Q000473:pathology; D045744:Cell Line, Tumor; D002533:Cerebral Angiography / Q000379:methods*; D002536:Cerebral Arteries / Q000000981:diagnostic imaging*; D002560:Cerebrovascular Circulation; D003287:Contrast Media; D003911:Dextrans; D007089:Image Enhancement / Q000379:methods; D018810:Magnetic Resonance Angiography / Q000379:methods*; D058185:Magnetite Nanoparticles; D009389:Neovascularization, Pathologic / Q000000981:diagnostic imaging* / Q000473:pathology; D051381:Rats; D017207:Rats, Sprague-Dawley; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; D003911:Dextrans; D058185:Magnetite Nanoparticles; C097921:ferumoxtran-10
keywords: dual-contrast SPION; micro-MR angiography; ultrashort echo