Frequency of Acute Adverse Events to a Non-Ionic Low-Osmolar Contrast Medium: The Effect of Verbal Interview

Abstract

The effect of a standardized verbal interview on the frequency of reported adverse events to an intravenous injection of a non-ionic low-osmolar magnetic resonance (MR) contrast medium was studied during a low noise (low anxiety) magnetic resonance imaging (MRI) examination. During a 26-month period 863 patients had an intravenous bolus (< 10 sec.) injection of either 0.1 mmol/kg b.wt. or 0.3 mmol/kg b.wt. gadodiamide, were examined in 0.1 Tesla (T) MRI unit. All patients received written information about the examination, but no specific information about possible adverse events to the contrast medium. During the first 15 months, 479 patients were asked after the examination by the same radiographer the following question "Did you feel anything in relation to or after the contrast medium injection?". If the answer was affirmative, the patient was asked to specify the experience. During the subsequent 11-month period, 384 patients had no interview about whether they felt anything in relation to the contrast medium injection. Only 9 out of 863 patients reported an adverse event and they all belonged to the group, which was interviewed. In 8 cases the adverse events lasted less than 5 min. The ninth patient had an attack of migraine 20 min. after the injection of the contrast medium. In one of the patients, who experienced nausea, it was necessary to postpone scanning for 2 min. Two of the 9 adverse events were considered to be unrelated to the contrast medium. None of the 121 patients receiving the triple dose reported an adverse event. The frequency of reported adverse events depends on whether this information is obtained by active questioning. All reported adverse events were clinically mild and no dose-response effect was observed.