Near infrared topographic imaging is an effective instrument to image brain-cortex activity. The light scattering in tissue prevents us from improving the spatial resolution of the reconstructed image; hence it is important to evaluate the effect of scattering on the spatial resolution of the image. In this study, the light propagation in the adult head model was predicted by Monte Carlo simulation to investigate the effect of fiber arrangement on the spatial resolution of NIR topographic imaging. The image of absorbers in the topographic images obtained from the double-density arrangement of source-detector pairs was compared with that from the conventional single-density arrangement. The double density arrangement improved the spatial resolution and accuracy of the position of the absorbers in the topographic image.