Abstract
Purpose: :
To determine whether intraocular lenses are compatible with 7T high field MRI.
Methods: :
A set of 23 intraocular lenses (IOLs) was selected based on the presence of dyes, metal and shape and MRI compatibility was evaluated in a high field 7T MRI scan according to ASTM International Standard Test Method (F2052-06). The magnetically induced displacement force was measured by the angular deflection using a test device. The degree of magnetic susceptibility artifacts was evaluated by positioning the IOLs in a gel and scanning the IOLs on the 7T MRI scanner using a 3D GRE sequence with long echo time. All images were visually inspected to determine the spatial extent of any signal voids.
Results: :
No displacement force was detected with any of the tested IOLs. A susceptibility artifact was observed at the position of the platinum part of the Worst Iris Clip IOL. None of the other 22 lenses caused susceptibility artifacts.
Conclusions: :
This is the first time IOLs are tested for 7T MRI compatibility. None of the IOLs were subject to magnetically induced movement. Only the Worst Iris Clip IOL caused an imaging artifact, none of the other IOLs did. For completion of safety criteria, data on radiofrequency induced heating should be obtained.
Keywords: intraocular lens • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)