BS 1. The role of MRI in PET/MRI

Key Questions

• How could we structure the examination protocols for PET/MRI for optimal diagnostic information in a minimum amount of time?

• Are there MR sequences which can be improved or adapted to the needs of PET/MRI and workflow?

• What are the best software solutions and approaches for convenient and reliable data storage?

Status Quo

◼ Two general approaches towards combined PET/MRI are available (simultaneous and sequential) facing similar problems, i.e. choice and amount of MRI sequences.

◼ There are several possibilities to create PET/MRI protocols depending on the choice of MR sequences, leading to examination times between 25 and 90 min or longer.

◼ MRI currently is performed in a multi-station, multi-contrast weighting fashion requiring time-consuming examination planning for whole-body imaging, thus resulting in non-optimized workflow.

◼ MR-based motion correction is promising in fully integrated systems with several limitations. Further developments will have an influence on the acceptance of MR-based motion corrections in clinical routine examinations.

Conclusions and Open Questions

➢ The amount of MRI performed depends on the underlying pathology, the clinical work-up as well as patient tolerance.

➢ MRI protocol and imaging workflow optimization is required since MRI is the limiting factor. This may involve the development and integration of easy-to-use moving table data acquisition strategies.

➢ Reimbursement will also influence the PET/MRI workflow since it has a major impact on the patient throughput.