In this chapter we introduce and review molecular sensitive imaging techniques that bridge the gap between ex-vivo and in-vivo analysis. In detail, we describe spontaneous Raman spectral imaging, coherent anti-Stokes Raman scattering (CARS), stimulated Raman scattering (SRS), second harmonic generation (SHG), third harmonic generation (THG), two-photon excited fluorescence (TPEF) and fluorescence lifetime imaging (FLIM). After reviewing these imaging techniques, we briefly introduce the chemometric and machine learning methods required to use these imaging techniques in diagnostic applications.