1. A method for real time Diffusive Optical Tomographic (DOT) imaging of a biological tissue of a subject comprising: (a) administering a fluorescent imaging probe to the subject for accumulation in a three-dimensional target region comprising the biological tissue, wherein the biological tissue of the subject has a volume V bounded by boundary S, and wherein the volume V is of arbitrary geometry; (b) directing excitation light waves into the biological tissue to cause the fluorescent imaging probe in the three-dimensional target region to emit fluorescent light; (c) using a detector to detect an intensity of the fluorescent light and the excitation light waves emitted from multiple points from the biological tissue by using non-contact measurements of the excitation light waves and the fluorescent light outside the biological tissue, where there is air between the detector and the biological tissue; and (d) processing the detected intensity of fluorescent light and the detected intensity of the excitation light waves to generate a tomographic image indicating the quantity of fluorescent imaging probe in the three-dimensional target region within the subject; wherein the tomographic image is generated by modeling propagation of diffuse photon waves inside the volume V taking into account the boundary surface S and a modeling of the intensities at the detector located outside the biological tissue of the subject.