UTE–ΔR2–ΔR2* combined MR whole‐brain angiogram using dual‐contrast superparamagnetic iron oxide nanoparticles. (7th April 2016)

• Record Type: Journal Article
• Authors: Jung, H. S.; Jin, S. H.; Cho, J. H.; Han, S. H.; Lee, D. K.; Cho, H.
• Is Part Of: NMR in biomedicine. Volume 29:Number 6(2016:Jun.)
• Page Start: 690
• Page End: 701
• Publication Date: 2016-04-07
• Subjects: micro‐MR angiography -- dual‐contrast SPION -- ultrashort echo; Nuclear magnetic resonance -- Periodicals; Magnetic Resonance Spectroscopy -- Periodicals; 574
• DOI: 10.1002/nbm.3514
• Languages: English
• ISSNs: 0952-3480

Abstract

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 Δ R 2 and Δ R 2 * 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 ( R 1 ) and transverse (Δ R 2 and Δ R 2 *) 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 Δ R 2 and Δ R 2 * MRA simultaneously improves the sensitivity to intracortical penetrating vessels and reduces vessel size overestimation. Consequently, UTE–Δ R 2 –Δ R 2 * 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. Abstract : Through Monte Carlo (MC) simulation and MR angiography (MRA) experiments in normal and tumor‐bearing animals with intravascular superparamagnetic iron oxide nanoparticles (SPION), we show that ultrashort TE (UTE) MRA acquires well‐defined vascularization on the brain surface, minimizing air–tissue artifacts, and the multiplied ΔR2 and ΔR2 * MRAs simultaneously improve the sensitivity to intracortical penetrating vessels and reduce 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 a more robust in vivo whole‐brain micro‐MRA.