Written informed consent for i.v. contrast-enhanced radiography: patients' attitudes and common limitations.

In a multiinstitutional study, we surveyed 902 patients who were undergoing IV contrast-enhanced CT or IV urography; the purpose of the study was to determine patients' reactions to being given a written description of some of the risks associated with radiographic contrast material just before undergoing the examination. Ninety percent of the patients who responded said they would rather receive this information than not receive it. Ten percent said they preferred not to be given the information. Limitations in obtaining a truly informed consent were not rare and occurred in patients with medical emergencies (3% of cases) and in those with a limited understanding of risk disclosure (11% of cases). Patients in the latter category included those who were comatose or semicomatose (2%), those with dementia (1%), those with aphasia (0.8%), those who had psychiatric problems (0.8%), those who were sedated (0.6%), those who were unable to read (2%), those who were unable to understand English (2%), and those who perceived the information as too technical (0.9%). Two percent of the patients were minors. Our survey shows that practical limitations in obtaining adequate risk disclosure are common, but most patients want and accept information about the risks of having IV contrast-enhanced CT or IV urography before undergoing the procedure.