A positron floodlight for PET attenuation measurements

A new technique to image the patient surface has been developed to assist in the segmented attenuation correction, currently finding favor in positron emission tomography (PET). The goals of this approach are to outline the body's contours quickly, with an inherent surface enhancement that would permit transmission scanning after the emission scan. To achieve this, an orbiting, thin-windowed source, mounted out of the detector plane, illuminates the patient's skin with a soft positron flux, while a static emission scan quickly delineates the patient outline. The ability to visualize internal structures is a welcome, if unexpected, windfall. The measurements of resolution and sensitivity cover a grid of three positron radionuclides and two source assemblies imaging several phantoms to challenge four commercial scanners. Currently mounted on a CTI 933/04, the positron floodlight is well suited to virtually any ring-array PET scanner, with the potential for adaptation to the dual-headed camera instruments emerging on the market today.