Applications of a PET device with 1.5 mm FWHM intrinsic spatial resolution to breast cancer imaging

Operation of a high resolution compact clinical PET Scanner (PEM Flex/spl trade/) device as a breast scanner is described. The device features high spatial resolution (1.5 mm FWHM intrinsic resolution) as a result of small crystals and compact position-sensitive photomultipliers. The compactness of the system allows it to reside within a stereotactic X-ray mammography unit, or as a separate standalone system capable of breast compression. The gamma rays are detected for a volumetric reconstruction by two heads, each of which contains 2,028 2 mm by 2 mm by 10 mm lutetium-containing crystals. The heads travel within X-ray transparent compression paddles. A window is provided in one of the paddles for direct correlation with ultrasound transducers and for interventional access. To enable real-time interventions, images are reconstructed and displayed while the detectors are still acquiring data. The maximum-likelihood reconstruction provides quantitative images with threefold improved contrast as compared to simple back-projections.