Figure 1.

Phases of acute kidney injury. This figure illustrates progression from kidney damage (or injury) occurring after contrast media exposure to clinical changes in kidney function. The subclinical AKI occurs in few hours following contrast media exposure. This phase may be captured only by biomarkers of kidney damage (like neutrophil gelatinase-associated lipocalin (NGAL)) but not those of kidney function (like serum creatinine (sCr) or cystatin C (sCyC)). Kidney damage, in the majority of cases, remains subclinical (subclinical AKI). However, subclinical AKI may progress in the clinical phase, as defined by a deterioration of kidney function, detectable by the eventual (within 48 hours) increase in sCyC and/or sCr.