Reducing MRI scanner duration project

Hi all, 

I'm scoping a project to help a secondary care team quantify carbon savings from work they've done to reduce the time people spent in MRI scanners, including reducing the need for general anaesthetics in kids. 

I think they'd be significant energy savings given my understanding is MRI scanners are 20-30kw/hr depending on scan (?), as well as benefits around anaesthetic gas/inpatient beds regarding the general anaesthetics.

Has anyone looked at anything similar or can signpost me to any useful resources / papers? 

Thanks!