Head and neck vessel magnetic resonance angiography appearance and artifacts after therapeutic intravenous ferumoxytol infusion

Intravenous ferumoxytol infusions are an effective treatment option for iron deficiency anemia. Ferumoxytol contains a superparamagnetic iron oxide core which causes artifacts on multiple MRI brain sequences. However, in our experience, there is not much information on the appearance of intracranial and neck vessels on MR angiography (MRA) after recent therapeutic i.v. administration of ferumoxytol. MRA is an integral part of the work-up for multiple diseases processes including for acute stroke and for detection of aneurysm(s), vasculopathy/vasculitis, vascular malformations, among others and are often performed without the acquisition of MRI brain. Without proper knowledge of the appearance of vessels after administration of i.v. feruomoxytol, radiologists may misinterpret the findings leading to unnecessary further investigation or errant diagnosis. We present the case of a patient who underwent MRI brain and MRA head and neck imaging after recent therapeutic i.v. infusion of ferumoxytol and discuss relevant imaging findings and imaging artifact caused by this medication.