Successful use of gadolinium contrast medium for flow-diverter stent placement in a patient with hypersensitivity to iodinated contrast: A case report.

Gadolinium contrast medium can serve as an alternative to iodinated contrast medium when the latter is unsuitable. In this report, we describe a case of a carotid-ophthalmic aneurysm in which angiograms were obtained using gadolinium contrast medium for flow-diverter stent placement due to the patient's history of bronchial asthma and hypersensitivity reactions to iodinated contrast medium. To enhance the visibility of gadolinium contrast medium, which typically provides lower contrast compared to iodinated contrast medium, we employed a contrast-enhancing and noise-reducing protocol on our image-guided therapy system. We performed catheterization and established working angles guided by a roadmap based on previous magnetic resonance angiography, the position of which was adjusted using cone-beam computed tomography performed before the intervention. This approach helped reduce the amount of contrast medium required. The procedure was successful and did not induce hypersensitivity reactions, morbidity, or mortality. Thus, the efficacy of the contrast-enhancing imaging protocol and the magnetic resonance angiography-based roadmap was confirmed. Measures must be taken to address gadolinium contrast medium-specific adverse events, limitations on the amount of contrast medium used, and the issue of low-contrast angiograms.