Anatomical findings in NCRNA. A–C. Orbital magnetic resonance images (MRI) of an 18-yr old male patient, showing absence or severe atrophy of the optic nerves and chiasm (red arrowheads), and bilateral detached retinas with vitreous consolidation (bright signal, blue arrowheads). A. Axial (TR/TE = 780/15 ms, 3 mm slices) and B. Oblique sagittal (right eye, TR/TE = 730/15 ms, 2 mm slice) T1-weighted SE views, with fat suppression and gadolinium contrast. C. Coronal T1-weighted SE views (TR/TE = 780/15, 5 mm slices) with no contrast or fat suppression, shown from anterior (left) to posterior (right). D. Matched coronal images from a normal 15-yr old female. T1-weighted SE views (TR/TE = 550/11 ms, 3 mm slices). The vitreae are clear (left panel, dark signal, blue arrowhead) and the optic nerves are prominent (middle panels, red arrowheads). The optic chiasm is visible above the suprasellar cistern and pituitary (right panel, red arrowhead). E. Matched axial images from the normal subject (TR/TE = 750/11 ms, 3 mm slices). F,G. Enlarged coronal views of NCRNA and normal subjects (left orbits, boxed areas in panels C and D). The red arrowhead shows the normal optic nerve. The bright T1W signal outlining the optic nerve, extraocular muscles (sr, lr, ir, mr, so, lps) and blood vessels (sov) originates from retrobulbar fat. 3v, third ventricle; cc, corpus callosum; cis, suprasellar cistern; eth, ethmoid sinus; hyp, hypothalamus; ica, internal carotid artery; io, inferior oblique; ir, inferior rectus; la, levator aponeurosis; lg, lacrimal gland; lps, levator palpebrae superioris; lr, lateral rectus; lv, lateral ventricle; max, maxillary sinus; mr, medial rectus; nph, nasopharynx; oa, ophthalmic artery; oc, optic canal; on, optic nerve; pit, pituitary gland; po, pons; ps, pituitary stalk; so, superior oblique; sov, superior orbital vein; sph, sphenoid sinus; sr, superior rectus; st, sella turcica; tem, temporal lobe; vit, vitreous; x, optic chiasm.