Pharmacokinetic models and parameters.

Ct(t), extracellular extravascular space contrast agent concentration; Cp(t), blood plasma contrast agent concentration; Ktrans, transfer constant; vp, blood plasma fraction; ve, extracellular extravascular volume fraction.Ct(t) 代表细胞外血管外间隙（extracellular extravascular space）内的对比剂浓度；Cp(t) 代表血浆内的对比剂浓度；Ktrans 为转运常数（transfer constant）；vp 为血浆分数；ve 为细胞外血管外容积分数。