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Late adverse events after enhanced and unenhanced MRI and CT: a prospective study
Manal Azzouz1, Janne Rømsing, Henrik S Thomsen
1Department of Diagnostic Radiology, Copenhagen University Hospital Herlev, Herlev, Denmark.
Abstract:
Prospective evaluation of frequency of late and very late adverse events in patients undergoing enhanced or unenhanced magnetic resonance imaging (MRI) or computed tomography (CT). The imaging procedure was performed according to the protocols of the department. All patients were contacted 3 days after their imaging procedure for the occurrence of late adverse events (LAEs) and a month later for the occurrence of very late adverse events (VLAEs) using a structured questionnaire. A total of 1042 (71%) among 1473 patients completed both the 3-day and 1-month questionnaire. The incidence of LAEs was significantly higher in the enhanced MRI (38%) and CT (27%) groups than unenhanced MRI (20%) and CT (16%) groups. The frequency of nausea, dizziness, abdominal pain and diarrhoea was significantly higher in the enhanced MRI group than in the MRI control group, while taste sensation was reported more frequent in the enhanced CT group than in the CT control group. The incidence of VLAEs was significantly higher in the enhanced CT (21%) than unenhanced CT group (13%). The same LAEs and VLAEs were reported in all four groups. LAEs and VLAEs were reported more often in patients with allergy in both the enhanced and unenhanced groups. The incidence of LAEs and VLAEs was higher in the enhanced groups than in the unenhanced groups. The most reported adverse events in the enhanced groups were also reported in the unenhanced groups. Patients with allergy reported LAE and VLAE more often. This suggests that adverse events may not always be caused by the contrast media.
Insights
Adverse events after enhanced MRI and CT scans were more frequent, especially in patients with allergies. Some events occurred even without contrast media, suggesting other causes for these late and very late adverse events.
Area of Science:
- Radiology
- Patient Safety
- Clinical Trials
Background:
- Adverse events (AEs) following medical imaging, particularly magnetic resonance imaging (MRI) and computed tomography (CT), are a concern.
- Understanding the frequency and nature of late and very late adverse events (LAEs and VLAEs) is crucial for patient safety.
Purpose of the Study:
- To prospectively evaluate the frequency of LAEs and VLAEs in patients undergoing enhanced or unenhanced MRI and CT.
- To compare AE incidence between enhanced and unenhanced imaging procedures and identify potential contributing factors.
Main Methods:
- A prospective study involving 1473 patients undergoing MRI or CT.
- Patients completed structured questionnaires at 3 days (LAEs) and 1 month (VLAEs) post-procedure.
- Data analyzed for incidence of AEs in enhanced vs. unenhanced groups, considering patient allergies.
Main Results:
- LAEs were more frequent with enhanced MRI (38%) and CT (27%) compared to unenhanced scans (20% and 16%).
- VLAEs were significantly higher in enhanced CT (21%) versus unenhanced CT (13%).
- Nausea, dizziness, and abdominal pain were more common with enhanced MRI; taste changes with enhanced CT. Patients with allergies reported more AEs regardless of contrast use.
Conclusions:
- Enhanced MRI and CT are associated with a higher incidence of LAEs and VLAEs compared to unenhanced procedures.
- The occurrence of similar AEs in both enhanced and unenhanced groups, and more frequently in allergic patients, suggests contrast media may not be the sole cause.
- Further investigation into the etiology of AEs in medical imaging is warranted.
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