CSF biomarkers targeting tau proteins are available just like with A\(\beta\), but the imaging biomarkers targeting tau are very recent developments and finding the best PET tracers that can bind with high sensitivity and selectivity to phosphorylated tau is an ongoing research topic \cite{Villemagne_2015}. High levels of total tau (t-Tau) and of phosphorylated tau (p-Tau) in CSF along with low levels of A\(\beta42\) have been shown to be highly predictive of MCI to AD converters \cite{Shaw_2009}. Since the tau is an intracellular protein binding to microtubules, in the CSF of healthy subjects they are found in low numbers. In taupathies these normal tau proteins become phosphorylated and get dissociated from microtubules, eventually contributing to the formation of NFTs \cite{Goedert_1993}. Tau protein could be released into CSF during the process of formation of NFTs and the subsequent disruption of neuronal architecture and cell deaths \cite{Formichi_2006}. Hence the elevated levels of t-Tau and p-Tau in CSF can correlate with the the onset of neurodegeneration in AD \cite{Anoop_2010}. There are several tau imaging ligands currently under research \cite{Villemagne_2015} with fluroine-18 (\(^{18}\)F) isotopes based PET tracers being the most promising \cite{Murray_2014}.