Patient complaints in radiology: 9-year experience at a European tertiary care center.

• Approximately 14.4 written patient complaints per 100,000 radiological procedures are filed in a European tertiary care center, and they have not increased over a 9-year period. • Written patient complaints most frequently involve interventional radiology, and the main complaint categories are quality (34.0%), safety (22.3%), timing and access (18.1%), and communication (18.1%). • Knowledge of the nature of and circumstances under which patient complaints arise may reduce their number and improve patient care.