Arterial Input Function (AIF) is fundamental for quantitative perfusion analysis. However, AIF peak is underestimated when using common perfusion sequence such SR-turboFLASH due to signal saturation effect. This leads to biased perfusion parameters estimation. Accurate AIF sampling requires specific sequence or protocol imaging not widely available. We proposed a solution to correct AIF peak retrospectively from standard perfusion data. We evaluated the proposed algorithm in simulation on more than 90000 different AIF sampling scenarios. Eventually, we tested our algorithm on clinical data and compared the population AIF estimated from our solution to literature population AIF.