Test liquids for quantitative MRI measurements of self-diffusion coefficient in vivo

A range of liquids suitable as quality control test objects for measuring t he accuracy of clinical MRI diffusion sequences (both apparent diffusion co efficient and tensor) has been identified and characterized. The self-diffu sion coefficients for 15 liquids (3 cyclic alkanes: cyclohexane to cyclooct ane, 9 n-alkanes: n-octane to n-hexadecane, and 3 n-alcohols: ethanol to 1- propanol) were measured at 15-30 degrees C using an NMR spectrometer. Value s at 22 degrees C range from 0.36 to 2.2 10(-9) m(2)s(-1). Typical 95% conf idence limits are +/-2%. Temperature coefficients are 1.7-3.2 %/degrees C. T-1 and T-2 values at 1.5 T and proton density are given. n-tridecane has a diffusion coefficient close to that of normal white matter. The longer n-a lkanes may be useful T-2 standards. Measurements from a spin-echo MRI seque nce agreed to within 2%. (C) 2000 Wiley-Liss, Inc.