In this letter, we demonstrate that back-directional gated imaging allows to dominantly attribute to the intensity of light backscattered from tissue, independent of scattering coefficients, and that the -weighted imaging method can provide a novel contrast for tumors in a mesoscopic (i.e., between microscopic and macroscopic) imaging setup. In our previous studies,3,4 we reported that back-directional gating can enhance contrast, resolution, imaging depth (1 to 1.5 mm), and imaging area (). In back-directional gating, a small aperture in the detection 4-focal length (4-f) lens system collects nearly exact backscattered light from tissue within a small angular cone of 2 to 5 deg. Unexpectedly from a Fourier optics standpoint, this configuration is highly beneficial to remove unwanted diffusive light because tissue is a highly anisotropic diffusive medium. Another key advantage of -weighted imaging is a large imaging area, compared with conventional microscopy methods. When tumors are heterogeneous in a large tissue area (e.g., ), examining a small area using microscopic techniques can fail to provide a representative or accurate assessment. In this study, we also show that the utilization of will be useful for mesoscopic imaging.