Figure 2From: Intraoperative renal near-infrared spectroscopy indicates developing acute kidney injury in infants undergoing cardiac surgery with cardiopulmonary bypass: a case–control study Example of calculating the area under the curve with the baseline of >25 % decrease of the preoperative individual averaged value of renal near-infrared spectroscopy. In this case, the area is calculated as 75% × 0.25 = 56%. NIRS, Near-infrared spectroscopy; rSO2, Regional oxygenation.Back to article page