Figure 7. Scattergrams showing the change in bolus width within a single slice of brain tissue plotted against contrast arrival time (TTM, time to mean contrast concentration). (a) The graph shows values from pixels with blood volume values greater than 5% (i.e. vessels) whereas (b) shows values from all pixels within the image. There is a clear linear relationship between contrast to age and duration and resulting from bolus dispersion of the contrast agent passes through the brain.