[en] The signal intensity obtained from an organism is determined by its tissue composition, the scanning technique, parameters of the apparatus, and other factors. We examined the influence of the partial volume effect on signal intensity and vision in the relation between voxel and photographic subject. We studied the influence that the photographic subject and slice thickness (slice face) exerted on signal intensity, and measured changes in signal intensity according to the positional relation between pixels and the photographic subject. From the results, we clarified the mechanism by which signal is given out from the voxel and examined the relation between the partial volume effect and signal intensity (contrast to noise ratio). We found that signal intensity is determined by the partial volume effect as determined by the ratio between the signal body and a substance set in the surroundings using a macro target and micro target. Moreover, the stimulation given to vision has the relation of a logarithm in contrast. We clarified that the CNR is applied as an approximate value. (author)