Mechanical Engineering Seminars - Second Harmonic Generation Imaging of Diseased States in Tissues
Ronald LaComb Ph.D.
We at Dr. Campagnola’s lab of the University of Connecticut Health Center (UCHC) are developing second harmonic generation SHG imaging microscopy as an “optical biopsy” tool to differentiate normal and diseases states. SHG microscopy produces three-dimensional images by galvanometricly scanning a laser focal spot in the XY directions, and stage translation in the Z “depth” direction. Images are produced in both the epi and transmission channels. Backward and forward images contain both coherent and incoherent signal components indicative of structurally dependent SHG creation and scattering. SHG is an exquisitely sensitive probe of the fibrillar structure in tissues as it directly visualizes supramolecular assembly, which may be different in diseased and healthy tissue. Quantitative tissue characterization is accomplished through utilization of a qualification metric. The qualification metric comprises of a set of SHG descriptors and phenomenological parameters ( which are determined through Monte Carlo techniques) to deconvolve SHG dependant morphological traits. Through comparative analysis, application of the metric enables differentiation between the diseased and normal state in noncentrosymmetric biological materials. Results will be presented for human ovarian cancer and murine Osteogenesis Imperfecta to demonstrate the efficacy of SHG imaging as a diagnostic tool.