Absent Vascular Signal on Time-of-Flight Magnetic Resonance Angiography Due to Recent Ferumoxytol Infusion

Area of Science:

• Radiology
• Vascular Imaging
• Neuroimaging

Background:

• Time-of-flight magnetic resonance angiography (TOF-MRA) is a key technique for evaluating craniocervical arteries.
• Absent flow-related signals in TOF-MRA can indicate slow flow, complex flow patterns, or susceptibility artifacts.
• Ferumoxytol is an intravenous iron replacement therapy approved for anemia in patients with chronic kidney disease.

Observation:

• A case presented with complete absence of expected flow-related signal in both intracranial and cervical vessels.
• The magnetic resonance angiography was performed five days after the patient received an infusion of ferumoxytol.
• This observation suggests a potential interaction between ferumoxytol and MRA signal generation.

Findings:

• Ferumoxytol administration led to a complete lack of flow-related signal in craniocervical arteries on TOF-MRA.
• The absence of signal was observed despite the presence of blood flow, indicating a masking effect.
• This finding is distinct from typical causes of absent signal like slow or complex flow.

Implications:

• Clinicians and radiologists must be aware of the potential for ferumoxytol to interfere with TOF-MRA.
• Understanding this drug-imaging interaction is crucial for accurate interpretation of craniocervical vascular imaging in patients treated with ferumoxytol.
• Further research may be needed to elucidate the exact mechanism of ferumoxytol's effect on MRA signal and to establish guidelines for imaging after administration.