“…Exploiting the spectrum of PA signal amplitude at a range of PA wave frequency, frequency domain analysis has shown potential in determining important parameters, such as the size and concentration, of the optical absorber and thus enabling the quantitative characterization of the prostate tissue, as demonstrated by Kumon et al, Sinha et al, and Patterson et al [87][88][89] Several challenges, however, are faced in the development of both PAI spectroscopy and frequency domain analysis towards clinical implementation. The spectral parameters are likely to be di®erent in an in vivo system, due to the overlying tissue; the algorithm for chromophore PA image reconstrucion is more complicated in reality, given that there are more components than dHb, HbO 2 , lipids, and water in biological tissues.…”