Meeting Banner
Abstract #1821

In Vivo 17O Measurements of Water Rotational Correlation Time and Hydrodynamic Radius in Rat Brain

Xiao-Hong Zhu1, Wei Chen1

1CMRR, Department of Radiology, University of Minnesota Medical School, Minneapolis, MN, United States

This study aims to exploit new MR approaches for noninvasively measuring the rotational correlation time (τ c) and hydrodynamic radius (Rh) of the brain tissue water. in vivo 17O MRS was used to measure T1 of the quadrupolar 17O spin of water in the rat brain at 9.4T, and to calculate τ c according to a simple, field-independent relation. 1H MRI was applied to image the brain translational diffusion coefficient (Dt); and the value of Rh was derived from the Dt/T1 ratio. It was found that i) the brain water τ c was in a range of several picoseconds and sensitive to brain temperature change, ii) Rh was about 1 that is in line with the water molecular size. This work indicates excellent utilities of in vivo 17O MRS for potentially imaging the microscopic matrix of brain tissue water properties in vivo.

Abstract PDF

Keywords

abundance according acquiring adiabatic animal animals applied approaches assessing asymmetry biological body brain brains bulk cellular chem coefficient coil colors conducted consisting console constant convincing correlation coupling covering dependence derived determine diffusion displays dominates dual dynamics electric environment equations essential evaluated evidence excellent expect exploits extra extreme extremely field fluctuation foundation frequency function functionalities gives gradients grants herein hong hydrodynamic in vivo increasing independence independent indicates indicating induced instance interact interaction interfaced intra inverse inversion leading limit linear local localized longer longitudinal magnet maintaining male measure measured measuring medical microscopic model molecular molecule moment motion narrowing natl natural novel obeys oval part picoseconds plays possesses potentially predicted probe process proposed pulse quantum radiology radius rats recovery reflect regression relation respectively reversed roles rotational scale school sensitive several shape shortened significantly simple slightly solid solving spaces spin stable stokes supported surface system temperature temporal theory though tissue translational trend unit utilities validity varied water