Figure 5.

(A and B) Coronal T2 and T2* images of neck before injection. (A) Asterisk and white arrow indicate the trachea and level of the thyroid cartilage before injection of the nanoparticles. (B) There is no significant susceptibility artifact in paratracheal location as indicated by the arrow. (C and D) Coronal T2 and T2* images acquired 4 weeks after the injection. Asterisk and white arrow indicate the trachea and level of the thyroid cartilage after the injection of the nanoparticles. (D) T2* image confirms the presence of iron nanoparticles (small arrowheads) at the injection site in the right paratracheal location.