The scheme of the experimental and reconstruction procedures is shown in Fig. 2. Dealing with irregular/asymmetric shapes as in the case of animals, a light propagation model for such geometries is required and two specific problems have to be faced. The first issue consists of obtaining the object volume to be meshed and provided to the propagation model. The second issue consists of determining the portion of the surface that should be illuminated for each view of the object. The two problems can be addressed optically using the described system based on DMD and CCD. It is worth stressing that, even if other methods12 can be used to acquire the shape of the object, the proposed method is extremely effective because it does not require any extra device. First, the animal was illuminated by a wide field beam larger than the object and its shadow is acquired at a fine step angle, typically 1 deg. By applying the inverse Radon transform on the stack of shadows, the 3-D volume of the sample could be reconstructed. The whole procedure requires the sample to be convex along the rotational plane (, ). This condition can be satisfied by limiting the measurement volume to the thorax and the abdomen. Then, the 3-D volume was used for creating a mesh of tetrahedral finite elements. In this work the iso2mesh mesh generation toolbox has been used.13 The selection of the area to be illuminated for each of the views used for fluorescence measurement requires special care and an adaptive approach. In fact, considering a wide area generally leads to very high transmitted intensity at the excitation wavelength close to the outline of the mouse body where the tissues are thinner. This leads to the saturation of the camera and, hence, to a poor exploitation of its dynamic range. On the other hand, a small illumination area reduces the total excitation power and diminishes the effectiveness of the structured light approach. In practice, the shadow images corresponding to the desired views were segmented, e.g., by applying a threshold, to recover the area corresponding to the animal position. The largest rectangle inscribed within the obtained area was retained as the illumination area.