A partially interconnected network comprises a plurality of allocated nodes, each allocated to one of a number of areas, a plurality of star nodes, and point-to-point interconnections between the allocated nodes and the star nodes. One or more imaging elements may be mounted to the anatomical positioning device in such a way that the placement of the imaging elements in relation to the anatomical positioning device and the subject can be easily controlled by the operator. Moreover, since the preserving vessel can be cooled by the liquid nitrogen when performing maintenance on the Stirling refrigerator, the specimens in the preserving vessel can always be cooled at a predetermined temperature or lower.