Implementation of true continuous 2D/3D whole body PET scanning

Abstract

True continuous axial bed motion has been implemented on a high resolution PET scanner for use in both 2D and 3D acquisition modes. This has been accomplished by modifications in the bed motion controller firmware and the use of acquiring data in list mode. The new bed controller firmware was shown to provide an accurate and constant bed speed down to 0.25 mm/s with patient weight load. The constant bed motion eliminates previously reported dead-time due to bed positioning when using small discrete bed steps. The continuous bed motion was tested on uniform phantoms, in 2D and 3D. As a result of the continuous axial motion, a uniform axial sensitivity is achieved. This was also reflected in the reconstructed images which showed an improved axial image uniformity (1.4% for continuous sampling, 5.0% for discrete) as well as an improvement in %SD uniformity in comparison to conventional step-and-shoot acquisitions. The use of the continuous axial motion also provide slight improvements in 2D emission and transmission scanning, resulting in an overall improved image quality in WB-PET.