Please see https://github.com/openmrs/openmrs-module-radiology#limitations. Ivo mentioned this here unable to add radiology orders in openmrs
Active development of the radiology module is going on under LibreHealth http://librehealth.io/projects/lh-radiology/ but it still doesn’t provide this feature. Right now we are currently building a new user interface for the module built as an OWA. Connecting the module to DCM4CHEE will be looked into once we wrap up with the UI.