Novel finding of optic nerve central T2 hypointensity utilizing 3 Tesla MR imaging.
We sought to report a central T2 hypointensity within the optic nerve on 3 T MRI studies obtained as part of the NASA Flight Medicine Visual Impairment Intracranial Pressure Protocol that had not been described previously. Twenty-one astronauts, who had undergone MRI of both orbits with direct coronal T2 sequences between 2010 and 2012, were retrospectively included. Two of the astronauts did not have previous exposure to microgravity at the time of their scans. A central T2 hypointensity was observed in 100% of both right and left eyes. It was completely visualized throughout the nerve course in 15 right eyes (71.4%) and in 19 left eyes (90.5%).We describe a new finding seen in all study participants: a central T2 hypointensity in the epicenter of the optic nerve. We speculate that this T2 hypointensity may represent flow voids caused by the central retinal vessels.
Department of Diagnostic and Interventional Imaging, The University of Texas in Houston roy.f.riascos@uth.tmc.edu.
Roy
R
Riascos
Department of Radiology, University of Texas Medical Branch, Houston, TX, USA.
John C
JC
Heymann
Department of Radiology, University of Texas Medical Branch, Houston, TX, USA.
Reza
R
Hakimelahi
Department of Diagnostic and Interventional Imaging, The University of Texas in Houston.
Khader
K
Hasan
Wyle Science, Technology & Engineering Group; USA.
Ashot
A
Sargsyan
University of Texas Medical Branch / NASA Johnson Space Center Bioastronautics Contract, Houston, TX, USA.
Yael R
YR
Barr
Department of Radiology, University of Texas Medical Branch, Houston, TX, USA.
James
J
Tom
Department of Radiology, The University of Miami, Coral Gables, FL, USA.
Noam
N
Alperin
Department of Diagnostic and Interventional Imaging, The University of Texas in Houston.
Larry A
LA
Kramer
D018480:Astronauts; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D036421:Nerve Fibers, Unmyelinated / Q000648:ultrastructure*; D009900:Optic Nerve / Q000166:cytology*; D014893:Weightlessness
3 Tesla; MR imaging; T2 hypointensity; optic nerve