Retrobulbar vasculature using 7-T magnetic resonance imaging with dedicated eye surface coil
To determine the resolution and utility of using a dedicated, single-loop eye coil at 7 T to image the posterior ocular structures and vascular anatomy.
Imaging was performed on eight subjects (age range 26–54 years, four female, four male) with 7 T using a transmit head coil for excitation and a dedicated 5-cm eye surface receive coil. Acquisition parameters at 7 T for 3D spoiled gradient echo (3D-SPGR) sequences were optimized.
It was possible to delineate the retina, sclera, and choroid, and fine details within the anterior and posterior segments of the eye. Retro-orbital and posterior ocular anatomy remained well visualized despite motion and susceptibility artifacts of anterior ocular structures. The ophthalmic arteries and their first-order branches were consistently visualized and improved with registration and summation of repeat scans. Furthermore, the central retinal vessels could be visualized. Intravenous gadolinium contrast reagent did not noticeably improve image quality.
High-resolution 7-T MRI with a dedicated eye coil can provide unique high-resolution noninvasive images of retro-orbital and posterior ocular structural and vascular anatomy and is able to resolve structures as small as the central retina vein.
KeywordsMagnetic resonance imaging Surface coil Orbital vessels
We thank Kathryn Richdale, OD, for her role and guidance in the development of MRI surface eye coil for patient use.
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