title: Development of an outdoor MRI system for measuring flow in a living tree.
abstract: An outdoor MRI system for noninvasive, long-term measurements of sap flow in a living tree in its natural environment has been developed. An open-access, 0.2 T permanent magnet with a 160 mm gap was combined with a radiofrequency probe, planar gradient coils, electromagnetic shielding, several electrical units, and a waterproofing box. Two-dimensional cross-sectional images were acquired for a ring-porous tree, and the anatomical structures, including xylem and phloem, were identified. The MRI flow measurements demonstrated the diurnal changes in flow velocity in the stem on a per-pixel basis. These results demonstrate that our outdoor MRI system is a powerful tool for studies of water transport in outdoor trees.
authors.affiliation: Institute of Applied Physics, University of Tsukuba, Tsukuba, Ibaraki, Japan.
authors.forename: Akiyoshi
authors.initials: A
authors.lastname: Nagata
authors.affiliation: Institute of Applied Physics, University of Tsukuba, Tsukuba, Ibaraki, Japan.
authors.forename: Katsumi
authors.initials: K
authors.lastname: Kose
authors.affiliation: Institute of Applied Physics, University of Tsukuba, Tsukuba, Ibaraki, Japan. Electronic address: terada@bk.tsukuba.ac.jp.
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Terada
mesh_terms: D000465:Algorithms; D019412:Anatomy, Cross-Sectional; D002940:Circadian Rhythm; D003198:Computer Simulation; D004574:Electromagnetic Fields; D008279:Magnetic Resonance Imaging / Q000379:methods*; D052585:Phloem / Q000033:anatomy & histology / Q000502:physiology; D011846:Radio Waves; D012621:Seasons; D014197:Trees / Q000033:anatomy & histology* / Q000502:physiology*; D014867:Water / Q000378:metabolism; D052584:Xylem / Q000033:anatomy & histology / Q000502:physiology
chemical_list: D014867:Water
keywords: Flow; Living tree; Outdoor MRI system; q-space imaging