Figure 6. Converting signal intensity into contrast concentration and model fitting. Data obtained from the patient illustrated Figure 4 for the tumour region of interest. Quantification of signal intensity data () into contrast agent concentration (•) is performed first according to the method described by Parker et al [61]. The model fitting procedure (continuous line) is done using the Tofts' model [81]. Note that model fitting to contrast agent concentration data is not perfect. Calculated quantified parameters are transfer constant=2.31 min^–1, leakage space 59%, maximum contrast medium concentration 0.50 mmol l^–1). Corresponding transfer constant (K^trans, colour scale 0–1 min^–1) and leakage space (v_e, colour scale 0–100%) pixel maps are also shown.