SAR Tomography (TomoSAR) is a multidimensional imaging technique that has proven its ability in localizing multiple scatterers in the three dimensional observed scene, allowing the reconstruction of the elevation profile of the structures on the ground. Tomographic approaches usually estimate the elevation distribution of the scetterers in each range-azimuth pixel independently from the neighboring ones (local approaches). Then, any relation among the elevations of neighboring pixels is imposed in the tomographic processing. In this paper a local contextual information contained in the data is exploited with the aim of improving the 3D reconstruction (semi-local approaches) and increase the number of reliable reconstructed scatterers in the tomographic scatterers cloud. Results on real data validate the proposed approach.