Evaluation of performance of dedicated, compact scintillation cameras

As part of the development of dedicated scintillation cameras, the authors compared the performances of 2 dedicated cameras with a standard clinical camera (Siemens Orbiter). One dedicated camera was based on a single Position Sensitive Photomultiplier (PSPMT) coupled to a 6 cm by 6 cm by 6 mm NaI(Tl) crystal and the other was based on multiple-PSPMTs coupled to a 2 mm by 2 mm by 6 mm matrix of NaI(Tl) crystals. Spatial resolution was measured with all cameras as a function of depth. The ability of the cameras to measure small superficial tumors was tested with a phantom consisting of 6 hot cylindrical tumors of height 3 mm and varying diameters against a warm background. The tumors were imaged at various depths within the background using tumor to background activity concentration ratios of 10:1 and 5:1. The dedicated cameras show improved performance in imaging the breast tumor phantom, suggesting that these devices will have a role in scintimammography and assisting in O.R, procedures such as sentinel node dissection and other shallow depth of field applications.