Perfusion computed tomography in renal cell carcinoma

Table 2 Computed tomography perfusion parameters[2-4]

Perfusion parameters	Definition	Unit	Biomarker
Regional blood flow	Blood flow per unit volume or mass of tissue	mL/100 mL per minute	Tumour vascularization
Regional tumour blood volume	Ratio of blood volume to tumour volume	mL/100 mL	Tumour vascularization
Permeability/blood flow extraction (PMB/PS/k-trans)	Rate of transfer of contrast agent from the intravascular to the extravascular compartment	mL/100 gm per minute	Vascular immaturity
Mean transit time	Average time taken to travel from artery to vein	s	Perfusion pressure
Time to peak	Time from arrival of the contrast in major arterial vessels to thepeak enhancement	s	Perfusion pressure
Maximum peak intensity	Maximum increase in tissue density after contrast injection	HU	Tissue blood volume