A two-dimensional (2D) shape-based approach of image reconstruction using a boundary element method is developed for diffuse optical tomography (DOT). The experimental validation uses a four-channel time-correlated single photon counting (TCSPC) system for detection and an intensity data-type for image reconstruction. The optical and geometric parameters are simultaneously recovered using a difference imaging scheme. Results demonstrate that the proposed DOT modality is a promising methodology of in vivo reconstruction of the optical structures of tissues.