Detection of apoptosis by optical coherence tomography (OCT)

Apoptosis is the effector of regulated cell death and plays a role in many physiologic and pathologic processes. It is characterized by a highly regulated condensation and fragmentation of the cell nucleus, a large scatterer, and breakup of the entire cell into vesicles, (apoptotic bodies) containing cell organelles and fragments of the nucleus. A two-fold increase in attenuation coefficient (mu) is observed in cell culture after chemical induction of apoptosis. An identical increase in scattering is observed in a tissue culture of porcine carotid artery, in which apoptosis is induced by balloon dilation. These observations are theoretically supported by calculations based on Mie theory. The preliminary results of this study indicate that the apoptotic process may be detected using OCT due to an increase in scattering by the typical disintegration of cellular material. The described increase in scattering may also be detected by other optical techniques.