This is the ValueSet that contains all the codes in eHDSI Imaging Observation Method (http://terminology.ehdsi.eu/ValueSet/eHDSIImagingObservationMethod) and eHDSI Imaging Observation Method (http://terminology.ehdsi.eu/ValueSet/eHDSIImagingObservationMethod). E.g. what you have to deal with if you get resources containing codes in either of them