Delayed Ferumoxtran-10-Enhanced Magnetic Resonance Neurography of the Lumbosacral Plexus: Impact on Vascular Suppression and Image Quality.

Background: Intravenous Ferumoxtran-10 belongs to ultra-small superparamagnetic iron oxide particles and can be used for magnetic resonance neurography (MRN) as an alternative to other imaging methods which use contrast agents.

Purpose: To examine the impact of intravenous Ferumoxtran-10 on vascular suppression and compare image quality to gadolinium (Gd)-enhanced image acquisition in MRN of lumbosacral plexus (LS).

Study type: Prospective.

Population/subjects: 17 patients with Ferumoxtran-10-enhanced MRN, and 20 patients with Gd-enhanced MRN.

Fieldstrength/sequence: 3T/3D STIR sequence.

Assessment: Image quality, nerve visibility and vascular suppression were evaluated by 3 readers using a 5-point Likert scale.

Statistical tests: Inter-reader agreement (IRA) was calculated using intraclass coefficients (ICC). Quantitative analysis of image quality was performed by signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) measurements and compared using Student's t-testing.

Results: Image quality, nerve visibility and vascular suppression were significantly higher for Ferumoxtran-10-enhanced MRN compared to Gd-enhanced MRN sequences (p < 0.05). IRA for image quality of nerves was good in Gd-enhanced and Ferumoxtran-10 MRN with ICC values of 0.76 and 0.89, respectively. IRA for nerve visibility was good in Gd- and Ferumoxtran-10 enhanced MR neurography (ICC 0.72 and 0.90). Mean SNR was significantly higher in Ferumoxtran-10-enhanced MRN for all analyzed structures, while mean CNR was for significantly better for S1 ganglion and femoral nerve in Ferumoxtran-10-enhanced MRN (p < 0.05).

Data conclusion: Ferumoxtran-10-enhanced MRN of the LS plexus showed significantly higher image quality and nerve visibility with better vascular suppression as compared to Gd-enhanced MRN.

Evidence level: 2 TECHNICAL EFFICACY: Stage 3.