Integrating imaging modalities: what makes sense from a workflow perspective?

PURPOSE: From a workflow/cost perspective integrated imaging is not an obvious solution. An analysis of scanning costs as a function of system cost and relevant imaging times is presented. This analysis ignores potential clinical advantages of integrated imaging.
METHODS: An analysis comparing separate vs integrated imaging costs was performed by deriving pertinent equations and using reasonable cost numbers for imaging devices and systems, room and other variable costs. Integrated systems were divided into those sequentially and simultaneously. Sequential scanning can be done with two devices placed in a single or in two different scanning rooms. Graphs were derived which represent the cost difference between integrated imaging system options and their separate counterparts vs scanning time on one of the devices and cost ratio of an integrated system and its counterpart of separate devices.
RESULTS: Integrated systems are favoured by the fact that patients have to be up- and downloaded only once. If imaging times become longer than patient changing times, imaging on separate devices is advantageous. An integrated imaging cost advantage is achieved if the integrated systems typically and overall cost three fourths or less of the separate systems. If PET imaging takes 15 min or less, PET/CT imaging costs less than separate PET and CT imaging, while this time is below 5 min for SPECT/CT. A two-room integrated system has the added advantage that patient download time is not cost relevant, when imaging times on the two devices differ by more than the patient download time.
CONCLUSION: PET/CT scanning is a cost-effective implementation of an integrated system unlike most current SPECT/CT systems. Integration of two devices in two rooms by a shuttle seems the way how to make PET/MR cost-effective and may well also be a design option for SPECT/CT systems.