A method and apparatus of obtaining and reconstructing an image of a portion of a body, administered by a radiopharmaceutical substance, by using Single-photon emission computerized tomography for determination of functional information thereon. The switching fabric is operable to couple select one or more visualization resource units to select one or more compute resource units for generating at least one graphical image. Where each of the light-emitting devices produces light having a non-uniform luminous intensity, each of the light-emitting devices is positioned with respect to one another to illuminate the surface of the light diffuser with an aggregate light having a substantially uniform luminous intensity. The foam made by this process and methods of protecting structures using the present foam system are also provided. The elongated light source is generally at the source focal point of the elongated reflector. The voltage can be incrementally varied until the head makes contact with the disk.