calculated glomerular filtration rate glomerular filtration rate index 2021-01-07T13:50:01Z CMO:0003628 K(cl) PMID:10913720 PMID:14561850 This index is the first order rate constant, k(cl), which describes the clearance of an extracellular contrast agent (Gd-DTPA (gadopentetic acid), Gd-DOTA (gadoteric acid), or gadoterate meglumine (organoammonium salt of gadoteric acid) from renal cortex to outer medulla as calculated according to the following equation: k(cl)=(dc[medulla]/dt)/c[cortex]. The concentration in the cortex (predominantly blood signal) is compared to the concentration in the medulla (predominantly urine). The clearance of the contrast agent can serve as a marker for the glomerular filtration rate. clinical_measurement_ontology slaulede