Figure 5.
Distribution volume varies with injection rate, injection volume, and ethyl cellulose concentration. (a) Representative images of 50 μL of ethanol or 3% ethyl cellulose-ethanol injected into agarose tissue phantoms at 10 mL/hr. Images were taken from the perspective with the widest cross-sectional area (“Front”) and the orthogonal perspective (“Side”). Distribution volume was calculated from front and side images of each phantom, assuming that the distribution shape was an ellipsoid. (b) Distribution volume as a function of injection volume for 10 mL/hr injections of either ethanol or 3% ethyl cellulose-ethanol. The linear fits had slopes of 8.1 and 4.7, respectively. Each injection volume was performed 5 to 7 times. (c) Distribution volume as a function of injection rate for both pure ethanol and 3% ethyl cellulose-ethanol. Mean distribution volume of ethyl cellulose solution was higher than for ethanol alone (p < 0.01, exact p-value < 10−7, chi-square = 29.04, degrees of freedom = 1). Each injection rate was evaluated 7 times. All error bars depict standard error of the mean.