Para-aminohippurate <unk>  is a method used in renal physiology to measure renal plasma flow, which is a measure of renal function.<unk>  is completely removed from blood that passes through the kidneys <unk>  undergoes both glomerular filtration and tubular secretion), and therefore the rate at which the kidneys can clear<unk>  from the blood reflects total renal plasma flow. The concentration of<unk>  is measured in one arterial blood sample (PPAH) and one urine sample(UPAH). The urine flow (V) is also measured. Renal perfusion flow is then calculated by: : What is calculated is the effective renal plasma flow (eRPF). However, since the renal extraction ratio of<unk>  almost equals 1, then eRPF almost equals RPF.
PAH clearance
Arterial input function
Free water clearance
Renal clearance ratio
Vascular resistance
Arterial resistivity index
Diffusing capacity
Oxygen enhancement ratio