Image fusion: Integrated PET-CT versus secondary image fusion [Bildfusionen: Integriertes PET-CT versus sekundäre bildfusion]

Electronic fusion of PET and CT image data sets obtained with hybrid PET-CT systems (integrated PET-CT) in order to improve the specificity of PET examinations is mainly supported by industrial and professional policy pressure groups. However, no qualitatively new diagnostic parameter is created by hybrid technologies. All diagnostic information is already provided by the original PET and CT images. There are only few medical indications for performing an integrated PET-CT based on the criteria of evidence-based medicine and radiation protection. Alternative electronic fusion of image data sets acquired independently from each other has the advantage of a free choice of modality (CT, MRI, PET) provided that the same body region was assessed using comparable geometric acquisition parameters. Comparatively lower costs and the independence of purchasing and maintenance of hybrid systems are further advantages. © 2009 Springer Medizin Verlag.