title: In vivo electrical conductivity imaging of a canine brain using a 3 T MREIT system.
abstract: Magnetic resonance electrical impedance tomography (MREIT) aims at producing high-resolution cross-sectional conductivity images of an electrically conducting object such as the human body. Following numerous phantom imaging experiments, the most recent study demonstrated successful conductivity image reconstructions of postmortem canine brains using a 3 T MREIT system with 40 mA imaging currents. Here, we report the results of in vivo animal imaging experiments using 5 mA imaging currents. To investigate any change of electrical conductivity due to brain ischemia, canine brains having a regional ischemic model were scanned along with separate scans of canine brains having no disease model. Reconstructed multi-slice conductivity images of in vivo canine brains with a pixel size of 1.4 mm showed a clear contrast between white and gray matter and also between normal and ischemic regions. We found that the conductivity value of an ischemic region decreased by about 10-14%. In a postmortem brain, conductivity values of white and gray matter decreased by about 4-8% compared to those in a live brain. Accumulating more experience of in vivo animal imaging experiments, we plan to move to human experiments. One of the important goals of our future work is the reduction of the imaging current to a level that a human subject can tolerate. The ability to acquire high-resolution conductivity images will find numerous clinical applications not supported by other medical imaging modalities. Potential applications in biology, chemistry and material science are also expected.
authors.affiliation: College of Electronics and Information, Kyung Hee University, Korea.
authors.forename: Hyung Joong
authors.initials: HJ
authors.lastname: Kim
authors.forename: Tong In
authors.initials: TI
authors.lastname: Oh
authors.forename: Young Tae
authors.initials: YT
authors.lastname: Kim
authors.forename: Byung Il
authors.initials: BI
authors.lastname: Lee
authors.forename: Eung Je
authors.initials: EJ
authors.lastname: Woo
authors.forename: Jin Keun
authors.initials: JK
authors.lastname: Seo
authors.forename: Soo Yeol
authors.initials: SY
authors.lastname: Lee
authors.forename: Ohin
authors.initials: O
authors.lastname: Kwon
authors.forename: Chunjae
authors.initials: C
authors.lastname: Park
authors.forename: Byeong Teck
authors.initials: BT
authors.lastname: Kang
authors.forename: Hee Myung
authors.initials: HM
authors.lastname: Park
mesh_terms: D000818:Animals; D001921:Brain / Q000502:physiology*; D004285:Dogs; D017097:Electric Impedance; D004566:Electrodes; D021621:Imaging, Three-Dimensional / Q000379:methods*; D009682:Magnetic Resonance Spectroscopy; D014054:Tomography / Q000379:methods*