Qualitative Solar Rotational Tomography (QSRT) is a breakthrough for mapping the coronal density structure. It uses normalized coronagraphic white light images for Fourier backprojection tomography, giving a detailed map of the coronal density structure. The technique is applied to LASCO/SOHO C2 data covering almost a whole solar activity cycle, and preliminary results are shown here. Reasonable agreement with the results of potential field source surface (PFSS) models is found, and the maps agree well with estimates of the density distribution estimated using global MHD models. A butterfly diagram of the latitude of coronal streamers against time over the last solar cycle is shown. The QSRT maps show direct evidence of differential rotation in the corona.