The perfect diagnostic imaging machine and what it means for quantitative MRI reproducibility

Starting from the recently published idea of the “perfect machine”, we argue that quantitative MRI (qMRI) supported by a rigorous metrological framework could not only drastically improve reproducibility in MRI and support large-scale studies, there is also scope to accredit individual MRI scanners in particular applications via a suitable accreditation scheme. We present the idea of the perfect diagnostic imaging machine, including describing the background of the ideas and how they lead to the idea of accreditation in qMRI. The scheme presented here is not intended to be the last word in accreditation, but to stimulate debate in the idea and whether or not is has merit for qMRI and its clinical and research context.